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This is RefScout-Newsletter 35/2004 for user Jeff32630.






REQUEST: [ leishmaniasis ]

(26 articles match this request)



PMID: 15322004
 

TITLE: Senescent BALB/c Mice Are Able To Develop Resistance to Leishmania major
Infection.

AUTHORS: Jan Ehrchen, Anca Sindrilaru, Stephan Grabbe, Frank Schönlau,
Christian Schlesiger, Clemens Sorg, Karin Scharffetter-Kochanek, Cord
Sunderkötter

AFFILIATION: Department of Dermatology and Allergology, University of Ulm,
Maienweg 12, 89081 Ulm, Germany. cord.sunderkoetter at medizin.uni-ulm.de

REFERENCE: Infect Immun 2004 Sep 72(9):5106-14

Aging has been associated with a decline in immunocompetence and 
resistance to infections, partially due to dysregulated NO production by
 macrophages and deficits in mounting Th2 cell responses. We wondered if
 these alterations would reverse the immune response in experimental 
leishmaniasis. Bone-marrow-derived macrophages from 2- and 18-month-old
 (senescent) C57BL/6 or BALB/c mice showed no marked difference in 
leishmanicidal functions. In vivo infections of resistant C57BL/6 mice 
with Leishmania major revealed no difference between senescent and young
 mice. However, among susceptible BALB/c mice, senescent animals showed 
less foot-pad swelling than young mice, and 40 to 60% of them even 
showed healing of ulcers, reduced parasite dissemination, and a Th1 cell
 response. These changes were associated with a spontaneous release of 
interleukin-12 (IL-12) by macrophages from aged but not from young mice
. Since exogenous microbial stimulation can influence immune responses 
during aging, we also infected senescent mice who were raised under 
specific-pathogen-free (SPF) conditions. They showed neither resistance 
nor a Th1 response, but their macrophages still spontaneously released 
IL-12. A microbiological analysis showed that conventionally kept mice, 
but not SPF mice, had experienced infection with murine hepatitis virus
 (MHV), an infection associated with a Th1-like response. We conclude 
that for the reversal of the immune response, senescence is the premier 
requirement but needs to be completed by another mandatory event such as
 microbial stimulation. One of the age-related, but not environment-
related, factors is the spontaneous release of IL-12 by macrophages, 
while confrontation with MHV presents an environment-related difference
, with both having the potential to support a Th1 response.








PMID: 15271903
 

TITLE: CD4+ Th1 cells induced by dendritic cell-based immunotherapy in mice
chronically infected with Leishmania amazonensis do not promote healing.

AUTHORS: Yannick F Vanloubbeeck, Amanda E Ramer, Fei Jie, Douglas E Jones

AFFILIATION: Department of Veterinary Pathology, College of Veterinary Medicine,
Iowa State University, Ames, IA 50011-1250, USA.

REFERENCE: Infect Immun 2004 Aug 72(8):4455-63

The susceptibility of mice to Leishmania amazonensis infection is 
thought to result from an inability to develop a Th1 response. Our data 
show that the low levels of gamma interferon (IFN-gamma) produced by the
 draining lymph node (DLN) cells of chronically infected mice could be 
enhanced in vitro and in vivo with L. amazonensis antigen-pulsed bone 
marrow-derived dendritic cells (BM-DC) and the Th1-promoting cytokine 
interleukin-12 (IL-12). Given intralesionally to chronically infected 
mice, this treatment induced the upregulation of mRNA levels for IFN-
gamma, the transcription factor T-box expressed in T cells, and IL-12 
receptor beta 2 in CD4(+) T cells from the DLN and an increase in 
parasite-specific immunoglobulin G2a in the serum. However, this Th1 
response was not associated with healing, and the antigen-specific 
enhancement of IFN-gamma production remained impaired in the DLN. 
However, addition of IL-12 to the in vitro recall response was able to 
recover this defect, suggesting that antigen-presenting cell-derived IL-
12 production may be limited in infected mice. This was supported by the
 fact that L. amazonensis amastigotes limited the production of IL-12p40
 from BM-DC in vitro. Altogether, our data indicate that the immune 
response of mice chronically infected with L. amazonensis can be 
enhanced towards a Th1 phenotype but that the presence of Th1 CD4(+) T 
cells does not promote healing. This suggests that the phenotype of the 
CD4(+) T cells may not always be indicative of protection to L. 
amazonensis infection. Furthermore, our data support growing evidence 
that antigen-presenting cell function, such as IL-12 production, may 
limit the immune response in L. amazonensis-infected mice.




PMID: 15278443
 

TITLE: The efficacy of enrofloxacin, alone or combined with metronidazole, in
the therapy of canine leishmaniasis.

AUTHORS: Paolo Bianciardi, Antonio Fasanella, Valentina Foglia Manzillo, Teresa
Trotta, Annalisa Pagano, Simona Sorino, Luigi Gradoni, Gaetano Oliva

AFFILIATION: DVM, Milano, Via Dell'Usignolo 1, 20147, Milan, Italy,
paolobianci at libero.it

REFERENCE: Parasitol Res 2004 Aug 93(6):486-92

We evaluated the efficacy of enrofloxacin, alone or combined with 
metronidazole, against Leishmania infantum. The in vitro activity of 
this fluoroquinolone was assessed using two different methods: a direct 
test aimed at assessing the drug activity on the parasite, and an 
indirect test aimed at evaluating the drug effect on macrophage killing
, lymphomonocyte activation and nitric oxide production. An in vivo test
 was also performed on 36 dogs with leishmaniasis, subdivided into three
 groups, one treated with enrofloxacin, another with enrofloxacin plus 
metronidazole, and a control group with meglumine antimoniate. The 
direct test did not show any action of enrofloxacin on the parasite, 
while the indirect testing showed an enhancement of macrophage killing 
and an increase in nitric oxide production. These findings show that 
enrofloxacin does not exert a direct anti-leishmanial activity in vitro
. However, on the basis of the positive immunostimulation results shown 
in vitro and the clinical improvement, particularly of the cutaneous 
lesions, obtained in several dogs in the in vivo trial, the use of 
enrofloxacin in association with a specific anti-leishmanial drug can be
 proposed in the therapeutic protocol of canine leishmaniasis.




PMID: 15271962
 

TITLE: DNA-Salmonella enterica serovar Typhimurium primer-booster vaccination
biases towards T helper 1 responses and enhances protection against Leishmania
major infection in mice.

AUTHORS: Uta G Lange, Pietro Mastroeni, Jenefer M Blackwell, Carmel B Stober

AFFILIATION: Cambridge Institute for Medical Research, and Department of
Medicine, School of Clinical Medicine, University of Cambridge, United
Kingdom.

REFERENCE: Infect Immun 2004 Aug 72(8):4924-8

Successful resolution of infections by intracellular pathogens requires 
gamma interferon (IFN-gamma). DNA vaccines promote T helper 1 (Th1) 
responses by triggering interleukin-12 (IL-12) release by dendritic 
cells (DC) through Toll-like receptor 9 (TLR9). In humans TLR9 is 
restricted to plasmacytoid DC. Here we show that DNA-Salmonella enterica
 serovar Typhimurium primer-booster vaccination, which provides 
alternative ligands to bind TLR4 on myeloid DC, strongly biases towards 
Th1 responses compared to vaccination with DNA alone. This results in 
higher immunoglobulin G2a (IgG2a) responses compared to IgG1 responses, 
higher IFN-gamma responses compared to IL-10 CD4(+)-T-cell responses, 
and enhanced protection against Leishmania major infection in 
susceptible BALB/c mice.




PMID: 15271961
 

TITLE: Involvement of the chemokine RANTES (CCL5) in resistance to experimental
infection with Leishmania major.

AUTHORS: Helton da Costa Santiago, Carolina Ferreira Oliveira, Luciana Santiago,
Fernanda Oliveira Ferraz, Daniele da Glória de Souza, Luiz Antônio Rodrigues
de-Freitas, Luís Carlos Crocco Afonso, Mauro Martins Teixeira, Ricardo Tostes
Gazzinelli, Leda Quercia Vieira

AFFILIATION: Departamento de Bioquímica e Imunologia, Instituto de Ciências
Biológicas, Universidade Federal de Minas Gerais, Brazil.

REFERENCE: Infect Immun 2004 Aug 72(8):4918-23

The expression and putative role of chemokines during infection with 
Leishmania major in mice were investigated. CCL5 expression correlates 
with resistance, and blockade of CCL5 rendered mice more susceptible to 
infection. CCL5 is part of the cascade of events leading to efficient 
parasite control in L. major infection.




PMID: 15271907
 

TITLE: Characterization of an I-E-restricted, gp63-specific, CD4-T-cell clone
from Leishmania major-resistant C3H mice that secretes type 2 cytokines and
exacerbates infection with L. major.

AUTHORS: Cynthia M Theodos, Robin V Morris, Jeanette V Bishop, Jeremy D Jones, W
Robert McMaster, Richard G Titus

AFFILIATION: Biogen, Inc., Cambridge, Massachusetts 02142, USA.

REFERENCE: Infect Immun 2004 Aug 72(8):4486-93

A T-cell clone (designated KLmB-3) was derived from resistant C3H mice 2
 weeks after infection with Leishmania major. KLmB-3 was a CD4-T-cell 
clone that utilized the V beta 8.1 T-cell receptor. When adoptively 
transferred to naive C3H mice, KLmB-3 unexpectedly exacerbated infection
 with L. major (it increased the cutaneous lesion size and the parasite 
burden within the lesion). The ability of KLmB-3 to exacerbate disease 
correlated with its ability to produce the type 2-associated cytokines 
interleukin-4 (IL-4), IL-5, IL-10, and transforming growth factor beta. 
Interestingly, KLmB-3 was specific for an epitope in the amino-terminal 
end of the L. major surface gp63 zinc metalloproteinase (leishmanolysin
) that has been shown to be capable of inducing a protective immune 
response. Moreover, KLmB-3 was activated when this epitope was presented
 in the context of H-2 I-E rather than H-2 I-A.




PMID: 15264486
 

TITLE: Causes of lymphadenopathy in the dog and cat.

AUTHORS: R Ruiz de Gopegui, B Peñalba, Y Espada

AFFILIATION: Department of Animal Medicine and Surgery, Facultad de Veterinaria,
Universidad Autónoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.

REFERENCE: Vet Rec 2004 Jul 155(1):23-4




PMID: 15311474
 

TITLE: Sand fly (Lutzomyia vexator) (Diptera: Psychodidae) populations in
upstate New York: abundance, microhabitat, and phenology.

AUTHORS: Richard S Ostfeld, Pamela Roy, Wendy Haumaier, Lauren Canter, Felicia
Keesing, Edgar D Rowton

AFFILIATION: Institute of Ecosystem Studies, Millbrook, NY 12545, USA.
rostfeld at ecostudies.org

REFERENCE: J Med Entomol 2004 Jul 41(4):774-8

Visceral leishmaniasis is an endemic protozoal disease of humans and 
dogs in tropical and subtropical regions in Asia, Africa, southern 
Europe, Central America, and South America, where sand flies (genera 
Phlebotomus and Lutzomyia) act as vectors. An outbreak in a New York 
foxhound kennel and subsequent surveillance revealed widespread 
Leishmania infantum infection of dogs in the United States, outside the 
known range of the vector sand flies. For this study, we conducted 
surveillance for sand flies during the summers of 2001 and 2002 at two 
areas: on the grounds of the New York kennel and at the Institute of 
Ecosystem Studies (IES) 10 km away. CO2-baited light traps were used for
 surveillance. Populations of Lutzomyia vexator, not previously known in
 New York, were widespread and locally abundant (range, 0.26-1.16 flies/
trap night) at the IES site. These populations showed a bimodal, 
midsummer activity peak and were most abundant on steep slopes within 
mature mixed hardwood forests. Further research will be necessary to 
determine whether the New York populations of L. vexator in the vicinity
 of the kennel could be involved in transmission of canine leishmaniasis.




PMID: 15316302
 

TITLE: [Mediterranean visceral leishmaniasis in immunocompetent children. Report
of two cases relapsed after specific therapy]

AUTHORS: C Colomba, F Scarlata, L Salsa, V Frasca Polara, L Titone

AFFILIATION: Istituto di Patologia Infettiva e Virologia, Universita degli Studi
di Palermo, Italy.

REFERENCE: Infez Med 2004 Jun 12(2):139-43

Visceral leishmaniasis (VL) is endemic in areas bordering the 
Mediterranean Sea (Spain, Italy, France, Greece, Morocco, Tunisia) where
 it is caused by Leishmania infantum and is transmitted by the bite of a
 hematophagous sandfly belonging to Phlebotomus spp.; the dog 
constitutes the main reservoir of infection. Two cases of VL in 
immunocompetent children are described. Both patients lived in endemic 
areas for leishmaniasis (Sicily) and at admission were febrile, pale and
 had splenomegaly. In both patients anti-leishmania antibodies were 
present and a definitive diagnosis was confirmed by demonstration of 
leishmania parasites by microscopy or polymerase chain reaction (PCR) in
 the bone marrow aspirates. The use of PCR performed on peripheral blood
 has been reported to be highly sensitive for the diagnosis and follow-
up of children with VL. One patient was treated with N-dimethylglucamine
, Glucantim, the other one with liposomal Amphotericin B (AmBisome). 
Both had symptomatic relapses 3 months later, and recovered following re
-treatment with AmBisome administered intravenously at a dosage of 3 mg/
Kg for ten consecutive days. The patients were monitored for one year 
after treatment was completed.




PMID: 15135980
 

TITLE: Sub-clinical infection as an effective protocol for obtaining
anti-Leishmania chagasi amastigote antibodies of different animal species.

AUTHORS: Adriana M Fróes, Cláudia V D dos Santos, Manoel L Penha-Filho,
Márcia C A Teixeira, Tânia Maria Correa Silva, Geraldo G Oliveira, Washington
L C dos Santos, Lain C Pontes-de-Carvalho, Neuza M Alcântara-Neves

AFFILIATION: Instituto de Ciências da Saúde, Universidade Federal da Bahia,
Avenida Reitor Miguel Calmon, s/n, Canela, 40.110-100 Salvador, Bahia, Brazil.

REFERENCE: Vet Immunol Immunopathol 2004 Jun 99(3-4):135-41

This work aims at identifying an effective protocol to raise anti-
Leishmania chagasi amastigote antibodies in different animal species. 
Protocols of immunization by subcutaneous injections of L. chagasi 
promastigote and amastigote lysates or by either intravenous or 
subcutaneous inoculation of live metacyclic promastigotes were assessed 
in mice, rabbits, and dogs. The immunization with live promastigotes 
produced a strong humoral immune response against L. chagasi amastigotes
 in all three animal species. The sera from animals immunized with the 
promastigote lysate did not react with amastigotes and, conversely, the 
sera from mice immunized with the amastigote lysate did not react with 
promastigotes. Taken all data together, the immunization through 
infection with metacyclic promastigotes was considered the most 
satisfactory way to immunize animals for obtaining anti-amastigote and 
anti-promastigote antibodies, since it did not only allowed the 
obtention of antibody against the two forms of the parasite, but it is 
also cheap, less laborious than carrying out the purification of 
amastigotes from infected tissues and avoid the use of a large number of
 hamsters for obtention the amastigotes, necessary to produce the 
immunogenic lysates. Furthermore, this immunization protocol was 
comparable to the amastigote lysate immunization protocol for the 
obtaining of mouse monoclonal antibodies (mAbs).




********************************************************************************************************************

 The following references are revised files and are brought to you in accordance
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PMID: 15107845
 

TITLE: Reciprocal CD40 signals through p38MAPK and ERK-1/2 induce counteracting
immune responses.

AUTHORS: Ram Kumar Mathur, Amit Awasthi, Pallavi Wadhone, B Ramanamurthy,
Bhaskar Saha

AFFILIATION: National Centre for Cell Science, Ganeshkhind, Pune 411007, India.

REFERENCE: Nat Med 2004 May 10(5):540-4

Macrophages play host to Leishmania major, a parasite that causes 
leishmaniasis in 500,000 people annually. Macrophage-expressed CD40, a 
costimulatory molecule, induces interleukin-12 (IL-12)-dependent and 
interferon-gamma (IFN-gamma)-dependent host-protective immune responses 
to Leishmania and other intracellular pathogens. Paradoxically, IL-10, 
another CD40-induced cytokine in macrophages, promotes Leishmania 
infection. How CD40 signaling regulates the secretion of these two 
counteractive cytokines remains unknown. Here we show that weak CD40 
signals induce extracellular stress-related kinase-1/2 (ERK-1/2)-
dependent IL-10 expression, whereas stronger signals induce p38 mitogen-
activated protein kinase (p38MAPK)-dependent IL-12 production. p38MAPK 
and ERK-1/2 therefore have counter-regulatory actions. Leishmania skews 
CD40 signaling toward ERK-1/2, inducing IL-10, which inhibits activation
 of CD40-induced p38MAPK and expression of inducible nitric oxide 
synthase-2 (iNOS-2) and IL-12. ERK-1/2 inhibition or IL-10 
neutralization restores CD40-induced p38MAPK activation and parasite 
killing in macrophages and the BALB/c mouse, a susceptible host. These 
data uncover a new immune evasion strategy, whereby Leishmania 
differentially modulates CD40-engaged, reciprocally functioning 
signaling modules, and provide a new conceptual framework for immune 
homeostasis.




PMID: 12585038
 

TITLE: Cytology of peritoneal leishmaniasis in a patient with AIDS.

AUTHORS: Olivier Oregioni, Pierre Marty, Yves Le Fichoux, Kathleen Angeli,
Céline Gorlier, Eric Rosenthal, Christophe Perrin

REFERENCE: Acta Cytol 2003 Jan-Feb 47(1):98-9




PMID: 12443799
 

TITLE: Molecular identification of vectors of Leishmania in Colombia:
mitochondrial introgression in the Lutzomyia townsendi series.

AUTHORS: J M Testa, J Montoya-Lerma, H Cadena, M Oviedo, P D Ready

AFFILIATION: Department of Entomology, The Natural History Museum, Cromwell
Road, London SW7 5BD, UK.

REFERENCE: Acta Trop 2002 Dec 84(3):205-18

The identity of the sandfly vectors of Leishmania braziliensis in Valle 
del Cauca Department, Colombia, was originally given as Lutzomyia 
townsendi, but then changed to L. youngi, another member of the L. 
townsendi series (Verrucarum group) with isomorphic females. To identify
 members of this series in Valle del Cauca, we analyzed the nuclear gene
 elongation factor-alpha (EF-alpha) and the mitochondrial gene 
cytochrome b (Cyt b). DNA sequences from the L. verrucarum series (L. 
columbiana, L. evansi and L. ovallesi) were used as outgroups. Flies 
from two locations on the western cordillera of the Andes were 
identified as L. townsendi s.s., according to male morphology and 
distinctive gene lineages. In the third location, on the central 
cordillera of the Andes, most specimens were identified as belonging to 
a geographical population of L. youngi, according to male morphology, an
 EF-alpha lineage shared with L. youngi from the Venezuelan-type 
locality, and a distinctive Cyt b sub-lineage. All other specimens were 
identified as L. youngi with the introgressed Cyt b sequences of L. 
townsendi. Such interspecific introgression implies that vectorial 
traits and ecological associations may no longer be viewed as fixed 
properties of different morphospecies.




PMID: 12516542
 

TITLE: Blockade of CD86 in BALB/c mice infected with Leishmania major does not
prevent the expansion of low avidity T cells.

AUTHORS: Monica Moro, Christophe Filippi, Alexandra Gallard, Laurent Malherbe,
Gilles Foucras, Hisaya Akiba, Hideo Yagita, Jean-Charles Guéry, Nicolas
Glaichenhaus

AFFILIATION: Centre National de la Recherche Scientifique, Valbonne, France.

REFERENCE: Eur J Immunol 2002 Dec 32(12):3566-75

The interactions between CD28 and its ligand CD86 are critical for the 
regulation of T cell responses. However, it is not clear whether CD4+ T 
cells expressing low and high avidity TCR are equally dependent on CD28 
costimulation for their activation and expansion. To address this issue
, we have used multimers of I-Ad molecules linked to a peptide derived 
from the Leishmania major homolog for the receptor of activated C kinase
 (LACK) antigen to compare the fate of LACK-specific CD4+ T cells in 
Leishmania-infected BALB/c mice which have been treated or not with anti
-CD86 mAb. Although the administration of anti-CD86 mAb did not 
completely prevent the expansion of LACK-specific T cells, their 
frequency and number were markedly reduced. In mice treated with anti-
CD86 mAb as well as in control animals, L. major induced the clonal 
expansion of LACK-specific T cells which expressed a canonical low 
avidity Valpha8/Vbeta4 TCR. Taken together, our results suggest that the
 molecular interactions between CD28 on T cells and CD86 on APC serve to
 amplify and modulate T cell responses without promoting breadth in the 
TCR repertoire.




PMID: 12653478
 

TITLE: The heat shock proteins, Hsp70 and Hsp83, of Leishmania infantum are
mitogens for mouse B cells.

AUTHORS: Ana I Rico, Núria Gironès, Manuel Fresno, Carlos Alonso, Jose M
Requena

AFFILIATION: Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Universidad
Autónoma de Madrid, Madrid 28049, Spain.

REFERENCE: Cell Stress Chaperones 2002 Oct 7(4):339-46

Extending earlier studies, this report demonstrates that Leishmania 
infantum heat shock proteins (Hsps), Hsp70 and Hsp83, expressed as 
recombinant proteins fused to the Escherichia coil maltose-binding 
protein (MBP), are potent mitogens for murine splenocytes. The response 
was not due to lipopolysaccharide (LPS) because the stimulatory activity
 of Hsp preparations was sensitive to boiling and trypsin treatments, 
whereas the corresponding activity of LPS was resistant to both 
treatments. It was found that in vitro incubation of spleen cells with 
the Leishmania Hsps leads to the expansion of CD220-bearing populations
, suggesting a direct effect of these proteins on B lymphocytes. In fact
, splenocytes from B cell-deficient mice did not proliferate in response
 to the Leishmania Hsps. In contrast, spleen cells from athymic nude 
mice were significantly stimulated by these recombinant proteins as an 
indication that the MBP-Hsp70 and MBP-Hsp83 recombinant proteins behave 
as T cell-independent mitogens of B cells. Furthermore, both proteins 
were able to induce proliferation on B cell populations purified from 
BALB/c spleen.




PMID: 12144696
 

TITLE: The period gene and genetic differentiation between three Brazilian
populations of Lutzomyia longipalpis.

AUTHORS: L G S R Bauzer, N A Souza, R D Ward, C P Kyriacou, A A Peixoto

AFFILIATION: Departamento de Bioquímica e Biologia Molecular, Departamento de
Entomologia, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.
apeixoto at ioc.fiocruz.br

REFERENCE: Insect Mol Biol 2002 Aug 11(4):315-23

Lutzomyia longipalpis (Diptera: Psychodidae: Phlebotominae), the main 
vector of visceral leishmaniasis in the Americas, is a putative species 
complex. Molecular polymorphism was characterized in a 266 bp fragment 
of L. longipalpis homologous to period, a 'speciation gene' from 
Drosophila. Samples from the Brazilian localities of Jacobina (BA), 
Lapinha (MG) and Natal (RN) were analysed and the data indicate that the
 three populations are highly differentiated, with a very low level of 
gene flow between them. These results are in agreement with published 
pheromone and copulation song studies that suggest the existence of a 
sibling species complex in Brazil.








PMID: 12117930
 

TITLE: Immunization with a polyprotein vaccine consisting of the T-Cell antigens
thiol-specific antioxidant, Leishmania major stress-inducible protein 1, and
Leishmania elongation initiation factor protects against leishmaniasis.

AUTHORS: Rhea N Coler, Yasir A W Skeiky, Karen Bernards, Kay Greeson, Darrick
Carter, Charisa D Cornellison, Farrokh Modabber, Antonio Campos-Neto, Steven G
Reed

AFFILIATION: Infectious Disease Research Institute, Seattle, Washington 98104,
USA. coler at idri.org

REFERENCE: Infect Immun 2002 Aug 70(8):4215-25

Development of an effective vaccine against Leishmania infection is a 
priority of tropical disease research. We have recently demonstrated 
protection against Leishmania major in the murine and nonhuman primate 
models with individual or combinations of purified leishmanial 
recombinant antigens delivered as plasmid DNA constructs or formulated 
with recombinant interleukin-12 (IL-12) as adjuvant. In the present 
study, we immunized BALB/c mice with a recombinant polyprotein 
comprising a tandem fusion of the leishmanial antigens thiol-specific 
antioxidant, L. major stress-inducible protein 1 (LmSTI1), and 
Leishmania elongation initiation factor (LeIF) delivered with adjuvants 
suitable for human use. Aspects of the safety, immunogenicity, and 
vaccine efficacy of formulations with each individual component, as well
 as the polyprotein referred to as Leish-111f, were assessed by using 
the L. major challenge model with BALB/c mice. No adverse reactions were
 observed when three subcutaneous injections of the Leish-111f 
polyprotein formulated with either MPL-squalene (SE) or Ribi 529-SE were
 given to BALB/c mice. A predominant Th1 immune response characterized 
by in vitro lymphocyte proliferation, gamma interferon production, and 
immunoglobulin G2A antibodies was observed with little, if any, IL-4. 
Moreover, Leish-111f formulated with MPL-SE conferred immunity to 
leishmaniasis for at least 3 months. These data demonstrate success at 
designing and developing a prophylactic leishmaniasis vaccine that 
proved effective in a preclinical model using multiple leishmanial 
antigens produced as a single protein delivered with a powerful Th1 
adjuvant suitable for human use.




PMID: 11820434
 

TITLE: ABC transporters in the protozoan parasite Leishmania.

AUTHORS: J M Pérez-Victoria, A Parodi-Talice, C Torres, F Gamarro, S Castanys

AFFILIATION: Instituto de Parasitología y Biomedicina López-Neyra, CSIC,
Granada, Spain.

REFERENCE: Int Microbiol 2001 Sep 4(3):159-66

ATP-binding cassette (ABC) transporters constitute one of the biggest 
and most conserved protein families in the evolutionary scale. Many of 
them are of enormous clinical relevance, due to their relationship with 
genetic diseases and drug resistance during the treatment of cancer and 
infectious diseases. Leishmaniasis is a major and globally widespread 
group of parasitic diseases, whose treatment has been complicated by the
 expansion of resistance to conventional drugs. Here, we review the 
current knowledge about ABC transporters in Leishmania spp, with special
 attention to their relationship with the drug-resistance phenotype.




PMID: 11207597
 

TITLE: Macrophage subsets harbouring Leishmania donovani in spleens of infected
BALB/c mice: localization and characterization.

AUTHORS: T Lang, P Avé, M Huerre, G Milon, J C Antoine

AFFILIATION: Département de Physiopathologie, Institut Pasteur, Paris, France.
tlang at pasteur.fr

REFERENCE: Cell Microbiol 2000 Oct 2(5):415-30

The purpose of the current study was to characterize parasite-containing
 cells located in spleens of BALB/c mice infected with Leishmania 
donovani. In particular, expression of MHC class II molecules by these 
cells was examined to determine whether they could potentially act as 
cells capable of immunostimulating Leishmania-reactive CD4+ T 
lymphocytes. To this end, an immunohistological analysis of spleens 
taken at various time points after infection was undertaken. Using this 
approach, we observed, in the red pulp, the formation of small cellular 
infliltrates containing heavily infected macrophages that could be 
stained with the monoclonal antibodies MOMA-2 and FA/11. All of them 
expressed high levels of MHC class II molecules. Parasites were also 
detected in the white pulp, especially in MOMA-2+, FA/11+ and MHC class 
II+ macrophages of the periarteriolar lymphocyte sheath and in MOMA-2+ 
marginal zone macrophages. Infected cells were further characterized by 
fluorescence microscopy after their enrichment by adherence. All 
infected mononuclear cells recovered by this procedure could be stained 
with MOMA-2 and FA/11 and thus very probably belonged to the mononuclear
 phagocyte lineage. Furthermore, all of them strongly expressed both MHC
 class II as well as H-2M molecules, regardless of the time points after
 infection. Analysis of the parasitophorous vacuoles (PV) by confocal 
microscopy showed that these compartments were surrounded by a membrane 
enriched in lysosomal glycoproteins lamp-1 and lamp-2, in macrosialin (a
 membrane protein of prelysosomes recognized by FA/11) and in MOMA-2 
antigen. About 80% of the PV also had MHC class II and H-2M molecules on
 their membrane. Altogether, these data indicate that in the spleens of 
L. donovani-infected mice, a high percentage of amastigotes are located 
in macrophages expressing MHC class II molecules and that they live in 
PV exhibiting properties similar to those of PV detected in mouse bone 
marrow-derived macrophages exposed to a low dose of interferon gamma (
IFN-gamma) and infected in vitro.




PMID: 10637281
 

TITLE: Critical contribution of OX40 ligand to T helper cell type 2
differentiation in experimental leishmaniasis.

AUTHORS: H Akiba, Y Miyahira, M Atsuta, K Takeda, C Nohara, T Futagawa, H
Matsuda, T Aoki, H Yagita, K Okumura

AFFILIATION: Department of Immunology, Juntendo University School of Medicine,
Tokyo 113-8421, Japan.

REFERENCE: J Exp Med 2000 Jan 191(2):375-80

Infection of inbred mouse strains with Leishmania major is a well 
characterized model for analysis of T helper (Th)1 and Th2 cell 
development in vivo. In this study, to address the role of costimulatory
 molecules CD27, CD30, 4-1BB, and OX40, which belong to the tumor 
necrosis factor receptor superfamily, in the development of Th1 and Th2 
cells in vivo, we administered monoclonal antibody (mAb) against their 
ligands, CD70, CD30 ligand (L), 4-1BBL, and OX40L, to mice infected with
 L. major. Whereas anti-CD70, anti-CD30L, and anti-4-1BBL mAb exhibited 
no effect in either susceptible BALB/c or resistant C57BL/6 mice, the 
administration of anti-OX40L mAb abrogated progressive disease in BALB/c
 mice. Flow cytometric analysis indicated that OX40 was expressed on CD4
(+) T cells and OX40L was expressed on CD11c(+) dendritic cells in the 
popliteal lymph nodes of L. major-infected BALB/c mice. In vitro 
stimulation of these CD4(+) T cells showed that anti-OX40L mAb treatment
 resulted in substantially reduced production of Th2 cytokines. Moreover
, this change in cytokine levels was associated with reduced levels of 
anti-L. major immunoglobulin (Ig)G1 and serum IgE. These results 
indicate that anti-OX40L mAb abrogated progressive leishmaniasis in BALB
/c mice by suppressing the development of Th2 responses, substantiating 
a critical role of OX40-OX40L interaction in Th2 development in vivo.




PMID: 10461949
 

TITLE: Possible role of the 34-kilodalton hyaluronic acid-binding protein in
visceral Leishmaniasis.

AUTHORS: C M Rao, P Salotra, K Datta

AFFILIATION: Biochemistry Laboratory, School of Environmental Sciences,
Jawaharal Nehru University, New Delhi, India.

REFERENCE: J Parasitol 1999 Aug 85(4):682-7

Leishmania donovani, the causative organism of human visceral 
leishmaniasis, invades host macrophages through its interaction with the
 cell surface molecules of target cells. The presence of a cell surface 
protein (Mr 34 kDa) having specific affinity toward hyaluronan (HA), a 
major extracellular matrix component, has been previously reported in 
macrophage cell lines. In order to identify the possible role of this HA
-binding protein (HABP) in leishmaniasis, initially we demonstrated its 
overexpression in spleen, liver, macrophages, and serum of hamsters 
infected with L. donovani. We further observed higher levels of HABP in 
the macrophage cell line J774.G8 upon infection with L. donovani. 
Finally, we observed a significant increase in the level of HABP in the 
serum of patients with kala-azar. In order to understand its functional 
role in leishmaniasis, we report here a significant inhibition of 
cellular phosphorylation of HABP in hamster macrophages infected with L
. donovani. Interestingly, the 34-kDa HABP was shown to bind with 2 
proteins of promastigotes as well as amastigotes of L. donovani (with 
molecular masses of 55 kDa and 30 kDa respectively), suggesting a 
possible role for HABP in adhesion during the interaction of 
promastigotes and macrophages.




PMID: 9393843
 

TITLE: Association of Leishmania heat shock protein 83 antigen and
immunoglobulin G4 antibody titers in Brazilian patients with diffuse cutaneous
leishmaniasis.

AUTHORS: Y A Skeiky, D R Benson, J L Costa, R Badaro, S G Reed

AFFILIATION: Corixa Corporation, Seattle, Washington 98104, USA.
Skeiky at Corixa.Com

REFERENCE: Infect Immun 1997 Dec 65(12):5368-70

Diffuse cutaneous leishmaniasis (DCL) is characterized by the presence 
of numerous nonulcerated nodules and plaques containing large numbers of
 Leishmania amazonensis parasites and few lymphoid elements. The immune 
responses of DCL patients reflect severe antigen-specific T-cell 
deficiencies, while the antibody response to Leishmania antigens is 
often accentuated. We report herein on the Leishmania antigen-specific 
antibody subclass distribution in DCL patients and demonstrate that a 
dominant antigen contributing to the biased immunoglobulin G4 antibody 
subclass in sera of DCL patients is Leishmania heat shock protein 83.




PMID: 9130657
 

TITLE: Epitope cleavage by Leishmania endopeptidase(s) limits the efficiency of
the exogenous pathway of major histocompatibility complex class I-associated
antigen presentation.

AUTHORS: M R Garcia, S Graham, R A Harris, S M Beverley, P M Kaye

AFFILIATION: Department of Medical Parasitology, London School of Hygiene and
Tropical Medicine, GB.

REFERENCE: Eur J Immunol 1997 Apr 27(4):1005-13

The activation of CD8+ T cell responses is commonplace during infection 
with a number of nonviral pathogens. Consequently, there has been much 
interest in the pathways of presentation of such exogenous antigens for 
major histocompatibility complex class I-restricted recognition. We had 
previously shown that Leishmania promastigotes transfected with the 
ovalbumin (OVA) gene could efficiently target OVA to the parasitophorous
 vacuole (PV), with subsequent recognition by class II-restricted T 
cells. We now report the results of studies aimed at evaluating the PV 
as a route of entry into the exogenous class I pathway. Bone marrow-
derived macrophages can present soluble OVA (albeit at high 
concentrations) to the OVA(257-264)-specific T cell hybridoma 13.13. In 
contrast, infection with OVA-transfected Leishmania promastigotes failed
 to result in the stimulation of this hybridoma. This appeared unrelated
 to variables such as antigen concentration, parasite survival, and 
macrophage activation status. These results prompted an analysis of the 
effects of promastigotes on class I peptide binding using RMA-S cells 
and OVA(257-264). Our data indicate that the major surface protease of 
Leishmania, gp63, inhibits this interaction by virtue of its 
endopeptidase activity against the OVA(257-264) peptide. The data 
suggest that this activity, if maintained within the PV, would result in
 loss of the OVA(257-264) epitope. Although we can therefore draw no 
conclusions from these studies regarding the efficiency of the PV as a 
site of entry of antigen into the exogenous class I pathway, we have 
identified a further means by which parasites may manipulate the immune 
repertoire of their host.




PMID: 8971277
 

TITLE: During canine leishmaniasis a protein belonging to the 83-kDa heat-shock
protein family elicits a strong humoral response.

AUTHORS: S O Angel, J M Requena, M Soto, D Criado, C Alonso

AFFILIATION: Centro de Biología Molecular Severo Ochoa (C.S.I.C.-U.A.M.),
Universidad Autónoma de Madrid, Spain.

REFERENCE: Acta Trop 1996 Sep 62(1):45-56

By screening of a Leishmania infantum expression library with the serum 
from a dog affected with visceral leishmaniasis, a cDNA clone with 
sequence homology to the Hsp83 gene family was isolated. From analysis 
of the genomic distribution of the cDNA sequence, it was estimated that 
the L. infantum genome contains 7 Hsp83 genes tandemly organized. The 
full-length coding region of the Hsp83 gene located at the 5'-end of the
 cluster was determined. The deduced amino acid sequence of the L. 
infantum Hsp83 shows a high level of sequence identity with members of 
the Hsp83's protein family from other eukaryotic organisms. The complete
 protein (LiHsp83) and 4 subfragments (LiA1, LiB1, LiC1 and LiD1) were 
expressed in Escherichia coli as recombinant proteins and used as target
 antigens in FAST-ELISA assays against a collection of sera from dogs 
with visceral leishmaniasis. Ninety percent of the sera recognized the 
recombinant LiHsp83, indicating that L. infantum Hsp83 is a potent 
immunogen during canine leishmaniasis. Serological analysis of the 
recombinant subfragments identified the LiB1 subfragment, from amino 
acid 156 to 283, as the immunodominant region of the protein. This 
region, which is the less evolutionary conserved region of the protein, 
was recognized by 88% of the visceral leishmaniasis sera. The results 
suggest that L. infantum Hsp83 and particular protein subfragments may 
be useful in serodiagnostic assays for canine leishmaniasis.




PMID: 7558326
 

TITLE: Immune responses of leishmaniasis patients to heat shock proteins of
Leishmania species and humans.

AUTHORS: Y A Skeiky, D R Benson, J A Guderian, J A Whittle, O Bacelar, E M
Carvalho, S G Reed

AFFILIATION: Infectious Disease Research Institute, Seattle, Washington 98104,
USA.

REFERENCE: Infect Immun 1995 Oct 63(10):4105-14

The course of human infection with Leishmania braziliensis is variable, 
ranging from self-healing infection to chronic disease. It is therefore 
a useful system in which to study immunoregulatory aspects of 
leishmaniasis, including the effects of parasite antigens on host 
responses. In the present study, we report on the cloning of, expression
 of, and comparative analyses of patient immune response to two 
different L. braziliensis genes homologous to the genes for the 
eukaryotic 83- and 70-kDa heat shock proteins. rLbhsp83 contains a 
potent T-cell epitope(s) which stimulated peripheral blood mononuclear 
cells (PBMC) from all L. braziliensis-infected individuals to 
proliferate and to produce interleukin-2 (IL-2) gamma interferon, and 
tumor necrosis factor alpha. The elicitation of IL-4 and IL-10 mRNAs was
 found to differ depending on the portion of the rLbhsp83 used to 
stimulate PBMC. rLbhsp83a, which represents the nearly full-length 
protein, stimulated IL-10 but not IL-4 mRNA. In contrast, a 
approximately 43-kDa protein representing the C-terminal region of 
Lbhsp83 stimulated the production of IL-4 but not IL-10 mRNA. rLbhsp70 
stimulated PBMC proliferation from patients with mucosal disease but, 
unlike rLbhsp83, did not stimulate PBMC from self-healing individuals. 
PBMC from mucosal patients were not stimulated by rHuhsp70 to either 
proliferate or produce cytokines. This suggests that the 
hyperresponsiveness of mucosal patient PBMC to Leishmania heat shock 
proteins does not involve an auto-immune phenomenon resulting from cross
-reactivity with self hsp70. In general, although the cytokine profile 
of patient PBMC in response to both of these Leishmania heat shock 
proteins represents a mixed Th1-Th2 pattern, the levels of gamma 
interferon and IL-2 were significantly higher than those of the Th2 
cytokines IL-4 and IL-10. Patients with active mucosal and cutaneous 
disease but not self-healing individuals had significant anti-
immunoglobulin G antibody titers to both rLbhsp83 and rLbhsp70 but not 
to the homologous rHuhsp70. It therefore appears that differential 
patient immune responses to Leishmania hsp83 and hsp70 may be of 
particular significance in the induction of protective immune responses 
as well as in the development of tissue damage in cases with 
particularly strong hypersensitive reactions.




PMID: 2717947
 

TITLE: Receptor-mediated drug delivery to macrophages in chemotherapy of
leishmaniasis.

AUTHORS: A Mukhopadhyay, G Chaudhuri, S K Arora, S Sehgal, S K Basu

AFFILIATION: Institute of Microbial Technology, Chandigarh, India.

REFERENCE: Science 1989 May 244(4905):705-7

Methotrexate coupled to maleylated bovine serum albumin was taken up 
efficiently through the "scavenger" receptors present on macrophages and
 led to selective killing of intracellular Leishmania mexicana 
amazonensis amastigotes in cultured hamster peritoneal macrophages. The 
drug conjugate was nearly 100 times as effective as free methotrexate in
 eliminating the intracellular parasites. Furthermore, in a model of 
experimental cutaneous leishmaniasis in hamsters, the drug conjugate 
brought about more than 90% reduction in the size of footpad lesions 
within 11 days. In contrast, the free drug at a similar concentration 
did not significantly affect lesion size. These studies demonstrate the 
potential of receptor-mediated drug delivery in the therapy of 
macrophage-associated diseases.




REQUEST: [ leishmania ]

(55 articles match this request. 20 articles matching other requests removed)



PMID: 15314146
 

TITLE: Modulation of the Leishmania donovani Peroxin 5 Quaternary Structure by
Peroxisomal Targeting Signal 1 Ligands.

AUTHORS: Kleber P Madrid, Gregory De Crescenzo, Shengwu Wang, Armando Jardim

AFFILIATION: Institute of Parasitology, McGill University, 21, 111 Lakeshore
Rd., Ste. Anne-de-Bellevue, Quebec H9X 3V9, Canada. armando.jardim at mcgill.ca

REFERENCE: Mol Cell Biol 2004 Sep 24(17):7331-44

The import of proteins containing the peroxisomal targeting signal 1 (
PTS1) into the Leishmania glycosome is dependent on the docking of the 
PTS1-loaded LdPEX5 cytosolic receptor with LdPEX14 on the glycosome 
surface. Here we show that, in the absence of PTS1, LdPEX5 is a tetramer
 that is stabilized by two distinct interaction domains; the first is a 
coiled-coil motif encompassing residues 277 to 310, whereas the second 
domain is localized to residues 1 to 202. By using microcalorimetry, 
surface plasmon resonance, and size exclusion chromatography techniques
, we show that PTS1 peptide binding to LdPEX5 tetramers promotes their 
dissociation into dimeric structures, which are stabilized by a coiled-
coil interaction. Moreover, we demonstrated that the resulting LdPEX5-
PTS1 complex is remarkably stable and exhibits extremely slow 
dissociation kinetics. However, binding of LdPEX14 to LdPEX5 modulates 
the LdPEX5-PTS1 affinity as it decreases the thermodynamic dissociation 
constant for this latter complex by 10-fold. These changes in the 
oligomeric state of LdPEX5 and in its affinity for PTS1 ligand upon 
LdPEX14 binding may explain how, under physiological conditions, LdPEX5 
can function to deliver and unload its cargo to the protein 
translocation machinery on the glycosomal membrane.




PMID: 15322011
 

TITLE: Chemokine Gene Expression in Toll-Like Receptor-Competent and -Deficient
Mice Infected with Leishmania major.

AUTHORS: Simone Antoniazi, Helen P Price, Pascale Kropf, Marina A Freudenberg,
Chris Galanos, Deborah F Smith, Ingrid Müller

AFFILIATION: Imperial College London, Faculty of Medicine, Department of
Immunology, Norfolk Place, London W2 1PG, United Kingdom.
i.muller at imperial.ac.uk

REFERENCE: Infect Immun 2004 Sep 72(9):5168-74

We studied the expression of a subset of chemokines, including RANTES/
CCL5, MIP-1alpha/CCL3, IP-10/CXCL10, and MCP-1/CCL2, in Toll-like 
receptor (TLR)-competent and -deficient mice after infection with 
Leishmania major. Chemokine expression at the site of infection (the 
footpad), in the draining lymph nodes and in the spleens of infected 
animals was determined by using two different methods of analysis. The 
results indicate that L. major infection causes overall upregulation of 
RANTES/CCL5, MIP-1alpha/CCL3, IP-10/CXCL10, and MCP-1/CCL2 in the 
footpads and lymph nodes, while expression of these chemokines is 
constitutive in the spleens of TLR4-competent mice (C57BL/10ScSn) and 
TLR4-deficient mice (C57BL10/ScN). Different patterns of expression were
 detected depending on the time postinfection, but there was little 
variation in the expression of these four chemokines in the presence or 
absence of TLR4.




PMID: 15149284
 

TITLE: Transketolase from Leishmania mexicana has a dual subcellular
localization.

AUTHORS: Nicola J Veitch, Dante A Maugeri, Juan Jose Cazzulo, Ylva Lindqvist,
Michael P Barrett

AFFILIATION: Division of Infection and Immunity, Institute of Biomedical and
Life Sciences, Joseph Black Building, University of Glasgow, Glasgow G12 8QQ,
Scotland, U.K.

REFERENCE: Biochem J 2004 Sep 382(Pt 2):759-67

Transketolase has been characterized in Leishmania mexicana. A gene 
encoding this enzyme was identified and cloned. The gene was expressed 
in Escherichia coli and the protein was purified and characterized. An 
apparent K(m) of 2.75 mM for ribose 5-phosphate was determined. X-ray 
crystallography was used to determine the three-dimensional structure of
 the enzyme to a resolution of 2.2 A (1 A identical with 0.1 nm). The C-
terminus of the protein contains a type-1 peroxisome-targeting signal, 
suggestive of a possible glycosomal subcellular localization. 
Subcellular localization experiments performed with promastigote forms 
of the parasite revealed that the protein was predominantly cytosolic, 
although a significant component of the total activity was associated 
with the glycosomes. Transketolase is thus the first enzyme of the 
nonoxidative branch of the pentose phosphate pathway whose presence has 
been demonstrated in a peroxisome-like organelle.




PMID: 15216854
 

TITLE: Cutaneous leishmaniasis, northern Afghanistan.

AUTHORS: Richard Reithinger, Khoksar Aadil, Samad Hami, Jan Kolaczinski

REFERENCE: Emerg Infect Dis 2004 May 10(5):966-7




********************************************************************************************************************

 The following references are revised files and are brought to you in accordance
to license agreement with the NLM.

********************************************************************************************************************


PMID: 15009071
 

TITLE: Development and functional analysis of eosinophils from murine embryonic
stem cells.

AUTHORS: Emi Hamaguchi-Tsuru, Atsuya Nobumoto, Noriyuki Hirose, Sayo Kataoka,
Kiyomi Fujikawa-Adachi, Masato Furuya, Akira Tominaga

AFFILIATION: Department of Molecular and Cellular Biology, Kochi Medical School,
Nankoku City, Kochi, Japan.

REFERENCE: Br J Haematol 2004 Mar 124(6):819-27

We have established a culture system for the development of eosinophils 
from murine embryonic stem (ES) cells. After transferring ES cells from 
embryonic fibroblast cells onto macrophage colony-stimulating factor-
deficient stromal cells, OP9, ES cells were cultured in the presence of 
interleukin (IL)-5 with either IL-3 or granulocyte-macrophage colony 
stimulating factor (GM-CSF) for 20 d to obtain approximately 50% 
eosinophils. Electron microscopy confirmed the presence of crystallized 
major basic protein (MBP) in the granules of some of these cells. 
Neither IL-5, IL-3, GM-CSF nor eotaxin alone could induce eosinophils as
 efficiently as the conditions described above. Eotaxin induced 
eosinophil development in combination with either IL-3 or IL-5. Levels 
of GATA-1, Friend of GATA (FOG)-1, PU.1, CCAAT/enhancer binding protein
 (C/EBP)alpha, C/EBPbeta, IL-3 receptor alpha (IL-3Ralpha), GM-CSF 
receptor alpha (GM-CSFRalpha), and MBP mRNAs were increased in ES cells 
10 d after transfer onto OP9 cells. In contrast, C/EBPepsilon, IL-
5Ralpha, and eosinophil peroxidase mRNAs were induced in response to IL-
3 and IL-5 after transfer onto OP9 cells. Eosinophils that developed in 
this system expressed Gr-1, F4/80, B220, CCR3, IL-3Ralpha, IL-5Ralpha, 
and DX5. Finally, eosinophils developed from ES cells produced reactive 
oxygen species in response to Leishmania as do peripheral blood 
eosinophils.




PMID: 11773050
 

TITLE: Unusual polypeptide synthesis in the kinetoplast-mitochondria from
Leishmania tarentolae. Identification of individual de novo translation
products.

AUTHORS: Anton Horváth, Martina Nebohácova, Julius Lukes, Dmitri A Maslov

AFFILIATION: Department of Biology, University of California, 3401 Watkins
Drive, Riverside, CA 92521, USA.

REFERENCE: J Biol Chem 2002 Mar 277(9):7222-30

The de novo synthesis of cytochrome c oxidase subunits I, II (COI and 
COII), and apocytochrome b (Cyb) was investigated in kinetoplast-
mitochondria of Leishmania. The organelles were isolated after breaking 
whole cells with nitrogen cavitation. Individual COI, COII, and Cyb 
polypeptides were identified by fractionation of the kinetoplast 
membranes, labeled with [(35)S]methionine and cysteine, using two-
dimensional (9 versus 14% and 20 versus 11%) denaturing gel 
electrophoresis. The reaction did not require exogenous energy sources 
or amino acids. On the contrary, the presence of amino acids other than 
methionine somewhat inhibited the labeling reaction probably by 
competing with the uptake of labeled amino acids. The synthesis reaction
 was insensitive to 100 microg/ml chloramphenicol, gentamycin, 
paromomycin, lincomycin, hygromycin, and tetracycline, as well as 
cycloheximide. The process showed a linear increase in the amount of 
synthesized polypeptides during the first 2 h of incubation, followed by
 a slower accumulation of products for up to 4 h. The de novo 
synthesized polypeptides were stable for several additional hours. Their
 assembly into respiratory complexes, investigated using two-dimensional
 Blue Native/N-[2-hydroxy-1,1-bis(hydroxymethyl)ethyl]glycine-SDS gels, 
began early during the incubation and continued throughout the course of
 the synthesis. This work represents the first unequivocal 
identification of the polypeptide synthesis in kinetoplasts.








PMID: 11598129
 

TITLE: Developmental regulation of heat shock protein 83 in Leishmania. 3'
processing and mRNA stability control transcript abundance, and translation id
directed by a determinant in the 3'-untranslated region.

AUTHORS: A Zilka, S Garlapati, E Dahan, V Yaolsky, M Shapira

AFFILIATION: Department of Life Sciences, Ben Gurion University of the Negev,
Beer-Sheva 84105, Israel.

REFERENCE: J Biol Chem 2001 Dec 276(51):47922-9

Developmental gene regulation in trypanosomatids proceeds exclusively by
 post-transcriptional mechanisms. Stability and abundance of heat shock 
protein (HSP)70 and HSP83 transcripts in Leishmania increase at 
mammalian-like temperatures, and their translation is enhanced. Here we 
report that the 3'-untranslated region (UTR) of HSP83 (886 nucleotides) 
confers the temperature-dependent pattern of regulation on a 
chloramphenicol acetyltransferase (CAT) reporter transcript. We also 
show that the majority of the 3'-UTR sequences are required for 
increasing mRNA stability during heat shock. Processing of the HSP70 and
 HSP83 primary transcripts to poly(A)(+) mRNA was more efficient during 
heat shock; therefore, even when stability at 33 degrees C was reduced 
by deletions in the 3'-UTR, transcripts still accumulated to comparable 
and even higher levels. Translation of heat shock transcripts in 
Leishmania increases dramatically upon temperature elevation. Unlike in 
other eukaryotes in which the 5'-UTR confers preferential translation on
 heat shock transcripts, we show that translational control of HSP83 in 
Leishmania originates from its 3'-UTR. The 5'-UTR alone cannot induce 
translation during heat shock, but it has a minor contribution when 
combined with the HSP83 3'-UTR. We identified an element located between
 positions 201 and 472 of the 3'-UTR which is essential for increasing 
translation of the CAT-HSP83 reporter RNA at 33-37 degrees C. This 
region confers preferential translation during heat shock even in 
transcripts that were less stable. Thus, investigating the traditionally
 conserved heat shock response reveals that Leishmania parasites use 
unique pathways for translational control.




PMID: 11770103
 

TITLE: Post transcriptional control of gene expression in Leishmania.

AUTHORS: M Shapira, A Zilka, S Garlapati, E Dahan, I Dahan, V Yavesky

AFFILIATION: Department of Life Sciences, Ben Gurion University of the Negev,
Beer-Sheva, Israel. shapiram at bgumail.bgu.ac.il

REFERENCE: Med Microbiol Immunol (Berl) 2001 Nov 190(1-2):23-6

Leishmania parasites are ancient eukaryotes, characterized by unusual 
molecular mechanisms. We have used the gene encoding for Hsp83 as a 
model system for studying regulatory mechanisms that control 
developmental gene regulation. We previously showed that protein coding 
genes are regulated exclusively by post-transcriptional mechanisms, 
while no transcriptional activation could be observed even for the 
conserved Hsp83 gene. We now show that processing and maturation of the 
Hsp83 polycistronic primary transcripts is more efficient at elevated 
temperatures. The mature transcripts are more stable during heat shock, 
with regulation conferred by 3' UTRs. Poly(A) tails of Hsp83 are 
approximately 30 nucleotides long, as common for other low eukaryotes. 
The mechanism that signals differential degradation is still unclear, 
since it was not possible to detect differences in deadenylation of 
Hsp83 transcripts at varying temperatures. Heat shock transcripts are 
preferentially translated at 33-37 degrees C, but unlike Drosophila, 
translational regulation is controlled by a region within the 3' UTR. 
Using this traditionally conserved system emphasizes that regulatory 
mechanisms in Leishmania differ from those prevailing in other 
eukaryotes.




PMID: 11481434
 

TITLE: Trypanosoma cruzi trans-sialidase: a potent and specific survival factor
for human Schwann cells by means of phosphatidylinositol 3-kinase/Akt
signaling.

AUTHORS: M V Chuenkova, F B Furnari, W K Cavenee, M A Pereira

AFFILIATION: Parasitology Research Center, Department of Pathology, Tufts
University School of Medicine, Boston, MA 02111, USA.

REFERENCE: Proc Natl Acad Sci U S A 2001 Aug 98(17):9936-41

Patients infected with Trypanosoma cruzi may remain asymptomatic for 
decades and show signs of neuroregeneration in the peripheral nervous 
system (PNS). In the absence of such neuroregeneration, patients may die
 in part by extensive neuronal destruction in the gastrointestinal tract
. Thus, T. cruzi may, despite their invasion of the PNS, directly 
prevent cell death to keep nerve destruction in check. Indeed, T. cruzi 
invasion of Schwann cells, their prime target in PNS, suppressed host-
cell apoptosis caused by growth-factor deprivation. The trans-sialidase
 (TS) of T. cruzi and the Cys-rich domain of TS reproduced the 
antiapoptotic activity of the parasites at doses (> or =3.0 nM) 
comparable or lower than those of bona fide mammalian growth factors. 
This effect was blocked by LY294002, an inhibitor of 
phosphatidylinositol 3-kinase (PI3K). TS also activated Akt, a 
downstream effector of PI3K. Ectopic expression of TS in an unrelated 
parasite, Leishmania major, turned those parasites into activators of 
Akt in Schwann cells. In contrast, the Cys-rich domain of TS did not 
block apoptosis in Schwann cells overexpressing dominant-negative Akt or
 constitutively active PTEN, a negative regulator of PI3K/Akt signaling
. The results demonstrate that T. cruzi, through its TS, triggers the 
survival of host Schwann cells via the PI3K/Akt pathway, suggesting a 
role for PI3K/Akt in the pathogenesis of Chagas' disease.




PMID: 11274727
 

TITLE: Analysis of the adjuvant effect of recombinant Leishmania infantum Hsp83
protein as a tool for vaccination.

AUTHORS: P Echeverria, G Dran, G Pereda, A I Rico, J M Requena, C Alonso, E
Guarnera, S O Angel

AFFILIATION: Instituto Nacional de Parasitología Dr. Mario F. Chaben/ANLIS Dr.
Carlos G. Malbran, Departamento de Parasitología Sanitaria, Av. Velez
Sarsfield 563, 1281, Buenos Aires, Argentina.

REFERENCE: Immunol Lett 2001 Mar 76(2):107-10

The properties of Leishmania infantum hsp83 (LiHsp83) to elicit an 
immune response against a fused reporter antigen, maltose binding 
protein (MBP), was studied. CF1 mice were immunized with different 
purified recombinant proteins: MBP, LiHsp83 and MBP fused to LiHsp83 (
MBP-LiHsp83). Serum samples were obtained at days 0, 21, 28, 60, 90, 120
 and 150 post-immunization. MBP-LiHsp83 fusion protein elicited a strong
 humoral response against MBP, higher than that one obtained in mice 
immunized with MBP alone or MBP mixed with LiHsp83, showing the 
secretion of both anti-MBP IgG2a and IgG1 isotypes (IgG2a/IgG1 ratio: 2:
1). This response was specific for recombinant proteins and was 
maintained for at least 150 days, whereas the reactivity in mice 
immunized with MBP alone dissapeared at day 90. After in vitro 
stimulation with MBP, spleen cells from MBP-LiHsp83 immunized mice 
showed higher proliferation indices and produced higher secretion of IFN
-gamma than spleen cells from either control or MBP-immunized mice. In 
all groups of mice IL-4 was undetectable. Thus we consider that LiHsp83 
may be a promising candidate to be used as carrier of fused antigens for
 adjuvant-free vaccination.




PMID: 11087934
 

TITLE: Trypanosoma brucei CYC1 does not have characteristics of a mitotic
cyclin.

AUTHORS: T C Hammarton, J R Ford, J C Mottram

AFFILIATION: The Wellcome Centre for Molecular Parasitology, University of
Glasgow, Anderson College, Glasgow G11 6NU, Scotland, UK.

REFERENCE: Mol Biochem Parasitol 2000 Nov 111(1):229-34




PMID: 11015439
 

TITLE: Interferon gamma signaling alters the function of T helper type 1 cells.

AUTHORS: G Z Tau, T von der Weid, B Lu, S Cowan, M Kvatyuk, A Pernis, G
Cattoretti, N S Braunstein, R L Coffman, P B Rothman

AFFILIATION: Integrated Program in Cell, Molecular and Biophysical Studies,
Columbia University, New York, New York 10032, USA.

REFERENCE: J Exp Med 2000 Oct 192(7):977-86

One mechanism regulating the ability of different subsets of T helper (
Th) cells to respond to cytokines is the differential expression of 
cytokine receptors. For example, Th2 cells express both chains of the 
interferon gamma receptor (IFN-gammaR), whereas Th1 cells do not express
 the second chain of the IFN-gammaR (IFN-gammaR2) and are therefore 
unresponsive to IFN-gamma. To determine whether the regulation of IFN-
gammaR2 expression, and therefore IFN-gamma responsiveness, is important
 for the differentiation of naive CD4(+) T cells into Th1 cells or for 
Th1 effector function, we generated mice in which transgenic (TG) 
expression of IFN-gammaR2 is controlled by the CD2 promoter and enhancer
. CD4(+) T cells from IFN-gammaR2 TG mice exhibit impaired Th1 
polarization potential in vitro. TG mice also display several defects in
 Th1-dependent immunity in vivo, including attenuated delayed-type 
hypersensitivity responses and decreased antigen-specific IFN-gamma 
production. In addition, TG mice mount impaired Th1 responses against 
Leishmania major, as manifested by increased parasitemia and more severe
 lesions than their wild-type littermates. Together, these data suggest 
that the sustained expression of IFN-gammaR2 inhibits Th1 
differentiation and function. Therefore, the acquisition of an IFN-gamma
-unresponsive phenotype in Th1 cells plays a crucial role in the 
development and function of these cells.




PMID: 11100898
 

TITLE: Identification of STKA-dependent genes in Dictyostelium discoideum.

AUTHORS: G Loughran, K Pinter, P C Newell, J D Gross

AFFILIATION: Dept. of Biochemistry, University of Oxford, United Kingdom.

REFERENCE: Differentiation 2000 Oct 66(2-3):71-80

During culmination of Dictyostelium aggregates, prespore and prestalk 
cells undergo terminal differentiation to form spores and a cellular 
stalk. Disruption of the cell-fate gene stkA leads to a phenotype in 
which all the cells destined to become spores end up as stalk cells. '
Stalky' mutants express normal levels of prespore cell transcripts but 
fail to produce the culmination-stage spore transcript spiA. The stkA 
gene encodes a putative GATA-type transcription factor (STKA). In order 
to identify possible downstream targets of STKA we used the technique of
 mRNA differential display and isolated four cDNA fragments that 
hybridise to mRNAs present during the later stages of development. All 
four gene tags were cloned and sequenced. mRNAs represented by these 
four sequence tags do not accumulate during culmination of 'stalky' 
cells and therefore must be specific to the spore pathway. By screening 
a cDNA library, longer cDNAs for all four were cloned and sequenced. 
Three of these contained complete protein-coding regions while only a 
partial cDNA was recovered for the fourth. One of the corresponding 
proteins has significant homology to a surface zinc metalloproteinase (
GP63) of the protozoan parasite Leishmania, while another is closely 
related to a human pre-RNA binding protein (hnRNP R).




PMID: 10722661
 

TITLE: Isolation of Trypanosoma brucei CYC2 and CYC3 cyclin genes by rescue of a
yeast G(1) cyclin mutant. Functional characterization of CYC2.

AUTHORS: J J Van Hellemond, P Neuville, R T Schwarz, K R Matthews, J C Mottram

AFFILIATION: Wellcome Centre for Molecular Parasitology, University of Glasgow,
Anderson College, Glasgow G11 6NU, Scotland, United Kingdom.

REFERENCE: J Biol Chem 2000 Mar 275(12):8315-23

Two Trypanosoma brucei cyclin genes, CYC2 and CYC3, have been isolated 
by rescue of the Saccharomyces cerevisiae mutant DL1, which is deficient
 in CLN G(1) cyclin function. CYC2 encodes a 24-kDa protein that has 
sequence identity to the Neurospora crassa PREG1 and the S. cerevisiae 
PHO80 cyclin. CYC3 has the most sequence identity to mitotic B-type 
cyclins from a variety of organisms. Both CYC2 and CYC3 are single-copy 
genes and expressed in all life cycle stages of the parasite. To 
determine if CYC2 is found in a complex with previously identified 
trypanosome cdc2-related kinases (CRKs), the CYC2 gene was fused to the 
TY epitope tag, integrated into the trypanosome genome, and expressed 
under inducible control. CYC2ty was found to associate with an active 
trypanosome CRK complex since CYC2ty bound to leishmanial p12(cks1), and
 histone H1 kinase activity was detected in CYC2ty immune-precipitated 
fractions. Gene knockout experiments provide evidence that CYC2 is an 
essential gene, and co-immune precipitations together with a two-hybrid 
interaction assay demonstrated that CYC2 interacts with CRK3. The CRK3 x
 CYC2ty complex, the first cyclin-dependent kinase complex identified in
 trypanosomes, was localized by immune fluorescence to the cytoplasm 
throughout the cell cycle.




PMID: 10698315
 

TITLE: Immunostimulatory properties of the Leishmania infantum heat shock
proteins HSP70 and HSP83.

AUTHORS: A I Rico, S O Angel, C Alonso, J M Requena

AFFILIATION: Centro de Biologia Molecular Severo Ochoa (CSIC-UAM), Universidad
Autónoma de Madrid, Spain.

REFERENCE: Mol Immunol 1999 Dec 36(17):1131-9

Emerging evidence indicates that the heat shock proteins (HSPs), a set 
of highly evolutionary conserved proteins, are playing essential roles 
in both normal processes of the immune system and specific immune 
responses. In a previous work, we demonstrated that the Leishmania 
infantum HSP70 possesses remarkable immunostimulatory properties. In the
 present work, we have extended the study to another HSP from this 
parasite, the HSP83. We show that this protein also has an adjuvant 
effect to an accompanying protein by stimulation of the humoral response
 when both proteins are fused and co-administered to BALBjc mice. The 
analysis of the IgG isotypes, IgG1 and IgG2a, indicated that the 
immunisations with the Leishmania HSPs, mainly the HSP70, potentiate a 
Thl-type response. It was found that the amino-terminal domain of the 
HSP70, the most evolutionary conserved region of the molecule, maintains
 the ability to stimulate the humoral response, whereas the carboxyl-
terminal domain does not have a similar effect. Unexpectedly, we found 
that the L. infantum HSP70 and HSP83 recombinant proteins stimulated the
 proliferation of spleen cells from unprimed BALB/c mice. Remarkably, 
this proliferation was abolished either by thermal denaturing of the 
proteins or by using specific antibodies. The use of the T-cell 
inhibitor cyclosporin A in the splenocytes proliferation assays 
suggested that both T- and non-T-cells are stimulated by the Leishmania 
HSPs. These findings may be relevant for therapeutic and prophylactic 
applications.




PMID: 10586044
 

TITLE: Robust B cell immunity but impaired T cell proliferation in the absence
of CD134 (OX40).

AUTHORS: S D Pippig, C Peña-Rossi, J Long, W R Godfrey, D J Fowell, S L Reiner,
M L Birkeland, R M Locksley, A N Barclay, N Killeen

AFFILIATION: Department of Microbiology and Immunology, University of
California, San Francisco 94143, USA.

REFERENCE: J Immunol 1999 Dec 163(12):6520-9

CD134 (OX40) is a member of the TNF receptor family that is expressed on
 activated T lymphocytes. T cells from mice that lack expression of 
CD134 made strong responses to a range of challenges, but they showed 
impaired proliferation in response to direct stimulation through the TCR
 with monoclonal anti-CD3epsilon Ab. CD134-deficient mice controlled 
infection with Leishmania major, Nippostrongylus brasiliensis, and 
Theiler's murine encephalomyelitis virus, and they made overtly normal 
Ab responses to a variety of antigens. Thus, CD134 is not essential for 
many T cell responses in vivo, nor is it required for the provision of 
help to B cells. Nonetheless, a subtle role in the regulation of T cell 
reactivity is suggested by the effect of CD134 deficiency on in vitro T 
cell responses.




PMID: 10376997
 

TITLE: Effect of acidic pH on heat shock gene expression in Leishmania.

AUTHORS: S Garlapati, E Dahan, M Shapira

AFFILIATION: Department of Life Sciences, Ben-Gurion University, Beer-Sheva,
Israel.

REFERENCE: Mol Biochem Parasitol 1999 May 100(1):95-101

Temperature and pH shifts trigger differential gene expression and stage
 transformation in Leishmania. The parasites encounter dramatic 
fluctuations in the extra-cellular pH between the mid-gut of the sand 
fly (pH>8) and the phagolysosomal vacuole of mammalian macrophages (pH&#
60;6). The authors examined the effect of pH shifts on heat shock gene 
expression in Leishmania amazonensis and Leishmania donovani 
promastigotes. Acidic pH resulted in preferential stability of the hsp83
 transcripts at 26 degrees C, but hsp transcripts were not 
preferentially translated as observed during heat shock. Pre-
conditioning of promastigotes to acidic pH did not alter the temperature
 threshold for hsp synthesis but lead to an increase in hsp synthesis 
mainly in L. donovani at 37 degrees C, and to a slight decrease in the 
arrest of tubulin synthesis in L. amazonensis. The stage specific 
morphological alterations that take place in vitro correlated with the 
arrest in tubulin synthesis and occurred at different temperatures in L
. donovani and L. amazonensis.




PMID: 9918676
 

TITLE: A high-yield, enzymatic synthesis of GDP-D-[3H]arabinose and
GDP-L-[3H]fucose.

AUTHORS: B J Mengeling, S J Turco

AFFILIATION: Department of Biochemistry, University of Kentucky Medical Center,
800 Rose Street, Lexington, Kentucky, 40536-0298, USA.

REFERENCE: Anal Biochem 1999 Feb 267(1):227-33

For assays involving glycosyltransferases or transporters, several GDP-
sugars are either commercially unavailable or expensive. We describe an 
enzymatic synthesis of GDP-d-[3H]arabinosep and GDP-l-[3H]fucose that 
yields 66-95% nucleotide-sugar from the appropriate radiolabeled sugar 
in less than 30 min. The coupled reaction requires Mg2+, ATP, and GTP 
along with the appropriate radioactive monosaccharide, sugar-1-kinase, 
and pyrophosphorylase. The latter two activities are present in a 
cytosolic fraction of Crithidia fasciculata, which is easily grown at 
room temperature in simple culture medium without serum or added CO2. 
Addition of commercial yeast inorganic pyrophosphatase shifts the 
equilibrium of the pyrophosphorylase reaction toward nucleotide-sugar 
formation. To verify that these nucleotide-sugars are biologically 
active, we tested their ability to serve as substrates for 
glycosyltransferases. GDP-l-[3H]fucose functions as the donor substrate 
for recombinant human fucosyltransferase V, and GDP-d-[3H]arabinosep 
serves as the donor substrate for the arabinosyltransferase activities 
present in Leishmania major microsomes.




PMID: 9818260
 

TITLE: Microbial glycoconjugates.

AUTHORS: B J Mengeling, S J Turco

AFFILIATION: Department of Biochemistry, University of Kentucky Medical Center,
Lexington 40536-0084, USA.

REFERENCE: Curr Opin Struct Biol 1998 Oct 8(5):572-7

The surfaces of all microbes are 'sugar coated' with molecules such as 
lipopolysaccharides in Gram-negative bacteria, capsular polysaccharides 
in bacteria, lipoarabinomannans in mycobacteria and lipophosphoglycan in
 Leishmania. The basic structures of these glycoconjugates are known and
, in the case of pathogens, they can function as virulence determinants
. Recent publications have refined some of these structures and have 
elucidated interesting genes and proteins responsible for their 
biosynthesis.




PMID: 9553063
 

TITLE: The crk3 gene of Leishmania mexicana encodes a stage-regulated
cdc2-related histone H1 kinase that associates with p12.

AUTHORS: K M Grant, P Hassan, J S Anderson, J C Mottram

AFFILIATION: Wellcome Unit of Molecular Parasitology, University of Glasgow, The
Anderson College, Glasgow G11 6NU, Scotland, United Kingdom.

REFERENCE: J Biol Chem 1998 Apr 273(17):10153-9

A cdc2-related protein kinase gene, crk3, has been isolated from the 
parasitic protozoan Leishmania mexicana. Data presented here suggests 
that crk3 is a good candidate to be the leishmanial cdc2 homologue but 
that the parasite protein has some characteristics which distinguish it 
from mammalian cdc2. crk3 is predicted to encode a 35.6-kDa protein with
 54% sequence identity with the human cyclin-dependent kinase cdc2 and 
78% identity with the Trypanosoma brucei CRK3. The trypanosomatid CRK3 
proteins have an unusual, poorly conserved 19-amino acid N-terminal 
extension not present in human cdc2. crk3 is single copy, and there is 5
-fold higher mRNA in the replicative promastigote life-cycle stage than 
in the non-dividing metacyclic form or mammalian amastigote form. A 
leishmanial suc-binding cdc2-related kinase (SBCRK) histone H1 kinase, 
has previously been described which binds the yeast protein, p13(suc1), 
and that has stage-regulated activity (Mottram J. C., Kinnaird, J., 
Shiels, B. R., Tait, A., and Barry, J. D. (1993) J. Biol. Chem. 268, 
21044-21051). CRK3 from cell extracts of the three life-cycle stages was
 found to bind p13(suc1) and the leishmanial homologue p12(cks1). CRK3 
fused with six histidines at the C terminus was expressed in L. mexicana
 and shown to have SBCRK histone H1 kinase activity. Depletion of 
histidine-tagged CRK3 from L. mexicana cell extracts, by Ni-
nitrilotriacetic acid agarose selection, reduced histone H1 kinase 
activity binding to p13(suc1). These data imply that crk3 encodes the 
kinase subunit of SBCRK. SBCRK and histidine-tagged CRK3 activities were
 inhibited by the purine analogue olomoucine with an IC50 of 28 and 42 
microM, respectively, 5-6-fold higher than human p34(cdc2)/cyclinB.




PMID: 9604886
 

TITLE: The Saccharomyces cerevisiae SOM1 gene: heterologous complementation
studies, homologues in other organisms, and association of the gene product
with the inner mitochondrial membrane.

AUTHORS: M Bauerfeind, K Esser, G Michaelis

AFFILIATION: Botanisches Institut, Heinrich-Heine-Universität, Düsseldorf,
Germany.

REFERENCE: Mol Gen Genet 1998 Apr 257(6):635-40

The small nuclear gene SOM1 of Saccharomyces cerevisiae was isolated as 
a multicopy suppressor of a mutation in the IMP1 gene, which encodes the
 mitochondrial inner membrane peptidase subunit 1 (Imp1). Analysis 
revealed that Som1 and Imp1 are components of a mitochondrial protein 
export system, and interaction between these two proteins is indicated 
by the genetic suppression data. Here we describe the identification of 
a gene from Kluyveromyces lactis, which restores respiratory function to
 a S. cerevisiae SOM1 deletion mutant at 28 degrees C. The sequence of 
the K. lactis gene predicts a protein product of 8.1-kDa, comprising 71 
amino acid residues, with a putative mitochondrial signal sequence at 
its N-terminus. The protein is 50% identical to its S. cerevisiae 
counterpart. The expression pattern of a homologous sequence in 
Leishmania major suggests a more general role for SOM1 in mitochondrial 
biogenesis and protein sorting. The various Som1 proteins exhibit a 
highly conserved region and a remarkable pattern of cysteine residues. A
 protein of the expected size was transcribed and translated in vitro. 
The Som1 protein was detected in fractions of S. cerevisiae enriched for
 mitochondria and found to be associated with the inner mitochondrial 
membrane.








PMID: 9364964
 

TITLE: Molecular characterization of the heat-inducible LmSTI1 protein of
Leishmania major.

AUTHORS: J R Webb, A Campos-Neto, Y A Skeiky, S G Reed

AFFILIATION: Infectious Disease Research Institute, Seattle, WA 98104, USA.

REFERENCE: Mol Biochem Parasitol 1997 Nov 89(2):179-93

We have recently isolated a cDNA encoding the Leishmania major homologue
 of the yeast stress-inducible protein STI1. Southern blot analyses 
indicate that this protein is encoded by a single copy gene in L. major 
and that this gene is highly conserved throughout the Leishmania genus. 
The STI1 gene is constitutively expressed in both L. major promastigotes
 and amastigotes however, STI1 transcript levels can be upregulated in 
promastigotes by a shift in culture temperature from 26 to 37 degrees C
. Upregulation of transcript was detectable within 5' of heat shock and 
continued to increase for a further 8 h before returning to constitutive
 levels. In addition, biosynthetic incorporation of [35S]methionine 
followed by immunoprecipitation revealed an increase in the level of 
nascent STI1 protein synthesized when promastigote cultures were shifted
 from 26 to 37 degrees C. The L. major STI1 protein and the heat shock 
proteins Hsp83 and Hsp70 form a salt-sensitive complex in L. major 
promastigotes as evidenced by co-immunoprecipitation using an antiserum 
specific for L. major STI1. Furthermore, this complex can be 
reconstituted in vitro by adding recombinant STI1 containing an amino-
terminal histidine tag to promastigote lysate and subsequent 
purification using metal chelate affinity chromatography.




PMID: 9272871
 

TITLE: Isolation of a mouse cDNA encoding mSTI1, a stress-inducible protein
containing the TPR motif.

AUTHORS: G L Blatch, M Lässle, B R Zetter, V Kundra

AFFILIATION: Department of Biochemistry, University of the Witwatersrand, South
Africa. 089blg at cosmos.wits.ac.za

REFERENCE: Gene 1997 Jul 194(2):277-82

We report the isolation and sequencing of the complete 2079-bp cDNA 
fragment encoding mSTI1, a murine stress-inducible protein. The 
predicted ORF encodes a protein of 543 amino acids (aa) and Mr 62,582. 
The predicted protein has significant homology to stress-inducible 
proteins from humans (IEF SSP 3521), soybean (GMSTI), yeast (STI1) and a
 parasite, Leishmania donovani (LSIP). All of these proteins contain 34-
aa repeat motifs, termed tetratricopeptide repeats (TPRs), that are 
proposed to be involved in intra- and intermolecular protein 
interactions. mSTI1 has ten potential TPR motifs, a putative nuclear 
localization signal (NLS), six potential phosphorylation sites for 
casein kinase II and a central proline-rich region. Western analysis 
detected a protein of approx. 63 kDa in all the major mouse organs and 
in mouse, monkey and human cell lines.




PMID: 9225771
 

TITLE: Transcription of the Leishmania major Hsp70-I gene locus does not proceed
through the noncoding region.

AUTHORS: A Dresel, J Clos

AFFILIATION: Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.

REFERENCE: Exp Parasitol 1997 Jul 86(3):206-12

Primary transcripts in kinetoplastid protozoa are generally assumed to 
be multicistronic. We have analyzed the transcription in the gene locus 
which encodes the 70-kDa heat shock protein by using nuclear run-on 
analysis. We find that RNA synthesis in the Hsp70-I gene locus either is
 terminated or pauses within the intergenic region approximately 250 nt 
downstream of the polyadenylation site. We therefore propose a 
discontinuous mode of transcription in the Hsp70 genes of Leishmania 
major.




PMID: 9065742
 

TITLE: Scavenger receptor-mediated delivery of antisense mini-exon
phosphorothioate oligonucleotide to Leishmania-infected macrophages. Selective
and efficient elimination of the parasite.

AUTHORS: G Chaudhuri

AFFILIATION: Division of Biomedical Sciences, Meharry Medical College,
Nashville, TN 37208, U.S.A. chaudh45 at ccvax.mmc.edu

REFERENCE: Biochem Pharmacol 1997 Feb 53(3):385-91

Targeted delivery of a 17-mer antisense phosphorothioate 
oligodeoxyribonucleotide, complementary to the common 5'-end of every 
mRNA of the parasite cells, to the phagolysosomes of cultured murine 
macrophages infected with Leishmania mexicana amazonensis selectively 
and efficiently eliminated the parasite cells without causing any 
detectable harm to the host cells. The antisense mini-exon 
oligonucleotide (ASM) was encapsulated into liposomes coated with 
maleylated bovine serum albumin (MBSA), the artificial ligand for 
macrophage scavenger receptors. MBSA-coating of the liposomes allowed 
specific binding of the liposomes to the macrophages, their receptor-
mediated uptake, and subsequent degradation of the liposomes inside 
macrophage phagolysosomes to release ASM. When incubated with Leishmania
-infected macrophages, MBSA-liposome-encapsulated ASM (10 microM) was 
able to kill >90% of the parasites within 5 hr as compared with 20% 
killing within this time period by free ASM. Oligonucleotides with 
complementary nucleotide sequence or with the same base composition as 
ASM but scrambled sequence had no antileishmanial effect under the 
conditions of the assay. This study reflects the efficacy of scavenger-
receptor-mediated delivery of antisense phosphorothioate oligos in 
killing intraphagolysosomal pathogens.




PMID: 8670159
 

TITLE: Leishmania mexicana p12cks1, a homologue of fission yeast p13suc1,
associates with a stage-regulated histone H1 kinase.

AUTHORS: J C Mottram, K M Grant

AFFILIATION: Wellcome Unit of Molecular Parasitology, University of Glasgow,
Scotland, UK.

REFERENCE: Biochem J 1996 Jun 316 ( Pt 3)():833-9

We have isolated a Leishmania mexicana homologue of the fission yeast 
suc1 gene using PCR with oligonucleotides designed to conserved regions 
of cdc2 kinase subunits (cks). The product of cks1 is a 12 kDa 
polypeptide, which has 70% identity with human p9cks1 and 44% identity 
with fission yeast p13suc1.p12cks1 was detected in the three life-cycle 
stages of L. mexicana by immunoblotting. Recombinant p12cks1 (p12cks1his
) bound to agarose beads was used as a matrix to affinity-select histone
 H1 kinase complexes from Leishmania, yeast and bovine extracts. 
Immunoblotting showed that yeast and bovine cdc2 kinase bound to 
p12cks1his, thus demonstrating functional homology between L. mexicana 
p12cks1 and yeast p13suc1. Histone H1 kinase activity was found at a 
high level in the proliferative promastigote and amastigote forms of L. 
mexicana, but at a low level in the non-dividing metacyclic form. These 
activities are likely to be the same as the leishmanial p13suc1 binding 
kinase (SBCRK) described previously [Mottram, Kinnaird, Shiels, Tait and
 Barry (1993) J. Biol. Chem. 268, 21044-21051]. A distinct cdc2-related 
kinase, L. mexicana CRK1, was also found to associate with p12cks1his 
but affinity-depletion experiments showed that CRK1 was not responsible 
for the histone H1 kinase activity associating with p12cks1his in 
promastigote cell extracts. The finding that p12cks1 associates with at 
least two cdc2-related kinases, SBCRK and CRK1, is consistent with the 
presence of a large gene family of cdc2-related kinases in 
trypanosomatids, a situation thought to be more similar to higher 
eukaryotes than yeast.




PMID: 8617351
 

TITLE: The genomic organization of the HSP83 gene locus is conserved in three
Leishmania species.

AUTHORS: A Hübel, J Clos

AFFILIATION: Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.

REFERENCE: Exp Parasitol 1996 Mar 82(2):225-8




PMID: 7646449
 

TITLE: High constitutive levels of heat-shock proteins in human-pathogenic
parasites of the genus Leishmania.

AUTHORS: S Brandau, A Dresel, J Clos

AFFILIATION: Leishmaniasis Research Group, Bernhard Nocht Institute for Tropical
Medicine, Hamburg, Federal Republic of Germany.

REFERENCE: Biochem J 1995 Aug 310 ( Pt 1)():225-32

We have analysed the transcription of three heat-shock genes, HSP70, 
HSP83 and ClpB, in the protozoan parasite Leishmania. All three heat-
shock genes are transcribed constitutively and not heat-inducibly. 
However, we find that two major heat-shock proteins, HSP70 and HSP83, 
are synthesized at elevated rates during heat stress. We conclude that 
the cellular stress response in Leishmaniae is regulated exclusively on 
a post-transcriptional level much in contrast with all other eukaryotes 
examined so far. The induced synthesis of HSP70 and HSP83, however, does
 not increase the steady-state level of either protein significantly. 
This is compensated by high constitutive levels of both proteins: HSP70 
and HSP83 make up 2.1% and 2.8%, respectively, of the total protein in 
unstressed Leishmania promastigotes. Also, HSP70 is a strictly 
cytoplasmic protein in Leishmania and does not relocate into the nucleus
 during heat stress, as it does in other eukaryotes examined in the past.




PMID: 7676903
 

TITLE: Distribution of developmentally regulated trans-sialidases in the
Kinetoplastida and characterization of a shed trans-sialidase activity from
procyclic Trypanosoma congolense.

AUTHORS: M Engstler, R Schauer, R Brun

AFFILIATION: Biochemisches Institut, Christian-Albrechts-Universität, Kiel,
FRG.

REFERENCE: Acta Trop 1995 May 59(2):117-29

The expression of developmentally regulated sialidase and trans-
sialidase activities in kinetoplastid protozoa was investigated. The 
occurrence of these enzymes was found not to be a common feature among 
the Kinetoplastida, but to be restricted to distinct developmental life 
cycle stages of only a few species. While sialidases without trans-
sialylating activities were demonstrated in Trypanosoma vivax and T. 
rangeli, trans-sialidase activity is expressed throughout the brucei-
group and in T. congolense. Neither T. evansi, nor T. equiperdum express
 sialidases or trans-sialidases. Furthermore, the absence of both, 
sialidase and trans-sialidase activities was proven in the Leishmania, 
Crithidia, Herpetomonas, Leptomonas and Phytomonas, respectively. In all
 species tested, the occurrence of sialic acids coincides with the 
expression of trans-sialidase activity. Those parasites, which lack 
trans-sialidases or only display regular sialidases, also lack cell-
bound sialic acids. The regular sialidase activity from bloodstream form
 T. vivax was characterized. The trans-sialidase from T. congolense is 
restricted to the procyclic culture forms and is shed into the culture 
medium. The enzyme has a pH-optimum at pH 7.0, displays sensitivity 
towards chlorides and is resistant against commonly used sialidase 
inhibitors. T. congolense trans-sialidase transfers preferentially alpha
(2-3)-linked sialic acids onto terminal beta-galactose residues. Also 
hydroxylated sialic acids (Neu5Gc) are transferred. The major 
glycoprotein GARP from procyclic T. congolense was identified as one 
potential natural sialic acid acceptor on the parasite's surface. In 
order to facilitate the characterization of trans-sialidases a novel, 
fluorimetric trans-sialidase assay was developed.




PMID: 7637691
 

TITLE: A member of the ClpB family of stress proteins is expressed during heat
shock in Leishmania spp.

AUTHORS: A Hübel, S Brandau, A Dresel, J Clos

AFFILIATION: Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.

REFERENCE: Mol Biochem Parasitol 1995 Mar 70(1-2):107-18

We have identified and isolated the Leishmania major homologue to the 
bacterial ClpB gene and to the yeast Hsp104 gene. ClpB in Leishmania 
major is a single-copy gene and encodes a low-abundance mRNA which is 
induced several-fold during a heat stress. We raised antibodies against 
the product of the recombinant gene and show that the leishmanial ClpB 
encodes a predominantly cytoplasmic protein of approx. 100 kDa which is 
detectable in Leishmania promastigotes of various species after exposure
 to elevated temperatures. We, therefore, term this protein Hsp100.




PMID: 7821406
 

TITLE: The hsp83 intergenic region in Leishmania: conservation of sequence and
function across two species.

AUTHORS: A Radi, A Miriam, S Michal

AFFILIATION: Department of Membrane Research and Biophysics, Weizmann Institute
of Science, Rehovot, Israel.

REFERENCE: Exp Parasitol 1995 Feb 80(1):159-62




PMID: 8078527
 

TITLE: Expression of heat shock protein 83 in Leishmania is regulated
post-transcriptionally.

AUTHORS: M Argaman, R Aly, M Shapira

AFFILIATION: Department of Membrane Research and Biophysics, Weizmann Institute
of Science, Rehovot, Israel.

REFERENCE: Mol Biochem Parasitol 1994 Mar 64(1):95-110

Mechanisms for regulation of heat shock protein (hsp) 83 expression were
 examined in Leishmania amazonesis. Transcripts of hsp83 accumulated 
upon temperature elevation; however, in contrast to non-protozoan 
eukaryotes (i.e. Drosophila, yeast, avian or human cells), no 
transcriptional activation was observed. The increase in the hsp83 mRNA 
level evolved from temperature induced variations in mRNA turn-over: the
 hsp83 transcript was rapidly degraded at normal temperatures, whereas 
heat shock led to its stabilization. The quick decay of the mRNA at 
lower temperatures was dependent on active protein synthesis. A similar 
pattern of regulation was observed for the transfected chloramphenicol 
acetyltransferase (CAT) gene, which was flanked by sequences from the 
hsp83 intergenic region (IR), and cloned into the pX transfection vector
 (pX-ICI). CAT mRNA was abundant at normal temperatures and further 
accumulated upon temperature elevation. The altered turn-over rates of 
CAT mRNA at the different temperatures were observed only in the 
presence of flanking hsp83 IR sequences. The increase in temperature 
also affected translational regulation of hsps, and synthesis of hsp83 
was more efficient at 35 degrees C than at 26 degrees C. However, the 
effect of translation was transient, and the steady state level of the 
protein was hardly altered.




PMID: 1377218
 

TITLE: Short amino acid sequences derived from C1q receptor (C1q-R) show
homology with the alpha chains of fibronectin and vitronectin receptors and
collagen type IV.

AUTHORS: B Ghebrehiwet, E I Peerschke, Y Hong, P Munoz, P D Gorevic

AFFILIATION: Department of Medicine, State University of New York, Stony Brook.

REFERENCE: J Leukoc Biol 1992 Jun 51(6):546-56

The human C1q receptor (C1q-R) is a 65-70-kd, highly acidic, hydrophobic
 glycoprotein that is expressed on a wide variety of cell surfaces. 
Although the C1q-R itself appears to bind preferentially to C1q, the 
region of the ligand to which C1q-R binds is the primary binding site 
for several other molecules, including fibronectin, laminin, and C1q 
inhibitor (chondroitin 4-sulfate proteoglycan) as well as the complement
 C1r2C1s2 tetramer. In order to further characterize the C1q-R molecule 
with regard to its structure and function, highly purified C1q-R was 
obtained from Raji cells using DEAE-Sephacel and C1q-Sepharose CL-4B 
chromatography. Studies performed with 125I-labeled C1q-R demonstrated 
that whereas the C1q-R molecule binds poorly to a variety of human 
collagens including types II, III, and V, markedly enhanced binding is 
observed with type IV collagen and moderately enhanced binding with type
 I collagen. Amino acid composition studies show that the C1q-R molecule
 contains approximately 44% hydrophobic and 12.6% hydrophilic residues 
with a ratio of negatively charged to positively charged residues of 
about 2:1. Treatment of 125I-labeled C1q-R with endoglycosidase F lowers
 the apparent molecular size from 70 to 58 kd, whereas endoglycosidase H
 lowered the size to 64 kd. Treatment with neuraminidase, on the other 
hand, shifted the size of C1q-R to 60 kd. These results suggest the 
presence of several highly sialylated complex-type or high mannose-type 
N-linked oligosaccharide side chains. Because purified C1q-R has a 
blocked amino terminus, amino acid sequences representing internal 
fragments of the molecule were generated by electroblotting and in situ 
enzymatic digestion. When these short sequences were searched against 
the National Biomedical Research Foundation computer data base, a seven-
amino-acid sequence, VSWQGQI, showed significant homology (100% and 80% 
in a five-amino-acid overlap, respectively) with the alpha chains of the
 human fibronectin (alpha 5 beta 1) and vitronectin (alpha v beta 3) 
receptors, and to a lesser degree with epidermal growth factor receptor 
and T cell receptor. A second sequence, ISEDNIR, showed homology with 
mouse collagen type IV (86% in a six-amino-acid overlap), calmodulin (60
% in a seven-amino-acid overlap), and a Leishmania major surface antigen
, gp63. These observations seem to predict that C1q-R has pockets of 
conserved sequences that are similar to those not only present in its 
ligand(s) but also in other cell surface receptors that may, in part, 
fulfill similar functions.




PMID: 3522261
 

TITLE: Leishmania mexicana: amastigote hydrolases in unusual lysosomes.

AUTHORS: M F Pupkis, L Tetley, G H Coombs

REFERENCE: Exp Parasitol 1986 Aug 62(1):29-39

Leishmania mexicana mexicana (M379) amastigotes were found to contain 
much higher activities than cultured promastigotes of five putative 
lysosomal enzymes: cysteine proteinase; arylsulfatase (EC 3.1.6.1); beta
-glucuronidase (EC 3.2.1.31); DNase (EC 3.1.22.1), and RNase (EC 3.1.27.
1). The release profiles of the first three of these enzymes from 
digitonin-permeabilized amastigotes suggests that they are located 
within organelles. Cytochemical staining for cysteine proteinase, using 
gold labeled antibodies and arylsulfatase, showed that both were present
 in large organelles previously named "megasomes." Comparative studies 
with L. mexicana amazonensis (LV78), L. donovani donovani (LV9), and L. 
major (LV39) revealed that L. mexicana amazonensis was similar to L. 
mexicana mexicana in possessing both high amastigote cysteine proteinase
 activity and large numbers of megasome organelles in amastigotes, 
whereas the other two species lacked both these features. The results 
suggest that the presence of numerous lysosome-like organelles in the 
amastigote is a characteristic of the L. mexicana group of parasites.




PMID: 2409075
 

TITLE: DNA amplification in antifolate-resistant Leishmania. The thymidylate
synthase-dihydrofolate reductase gene and abundant mRNAs.

AUTHORS: W L Washtien, R Grumont, D V Santi

REFERENCE: J Biol Chem 1985 Jul 260(13):7809-12

Leishmania tropica promastigotes selected for resistance to the 
dihydrofolate reductase inhibitor, methotrexate, or the thymidylate 
synthase inhibitor, 5,8-dideaza-10-propargyl folate, overproduce a 
bifunctional thymidylate synthase-dihydrofolate reductase and possess a 
30-kilobase region of amplified DNA. Five fragments, resulting from 
BglII digestion of this amplified DNA, were cloned into vectors and 
utilized as probes to examine mRNA in these organisms. Four mRNA species
 which hybridize to the amplified DNA sequences were found in both 
resistant and wild-type Leishmania, but were about 40-fold more abundant
 in the drug-resistant cells. Three of the four mRNAs are transcribed 
from the same strand of DNA, are clustered, and appear to have partial 
overlapping sequences. The thymidylate synthase-dihydrofolate reductase 
gene was localized to a specific region of the amplified unit of DNA by 
hybridization with mouse cDNA containing thymidylate synthase sequences 
and with a synthetic oligonucleotide 41 nucleotides in length, prepared 
on the basis of the partial amino acid sequence of the Leishmania enzyme
. Furthermore, mRNA hybrid-selected using a plasmid containing sequences
 of the putative gene was shown to direct in vitro synthesis of the 
bifunctional protein.




REQUEST: [ sand fly ]

(3 articles match this request. 2 articles matching other requests removed)



********************************************************************************************************************

 The following references are revised files and are brought to you in accordance
to license agreement with the NLM.

********************************************************************************************************************


PMID: 11296829
 

TITLE: Wolbachia infections of phlebotomine sand flies (Diptera: Psychodidae).

AUTHORS: M Ono, H R Braig, L E Munstermann, C Ferro, S L O'Neill

AFFILIATION: Department of Epidemiology and Public Health, Yale University
School of Medicine, New Haven, CT 06520, USA.

REFERENCE: J Med Entomol 2001 Mar 38(2):237-41

Old and New World phlebotomine sand fly species were screened for 
infection with Wolbachia, intracellular bacterial endosymbionts found in
 many arthropods and filarial nematodes. Of 53 samples representing 15 
species, nine samples offour species were found positive for Wolbachia 
by polymerase chain reaction amplification using primers for the 
Wolbachia surface protein (wsp) gene. Five of the wsp gene fragments 
from four species were cloned, sequenced, and used for phylogenetic 
analysis. These wsp sequences were placed in three different clades 
within the arthropod associated Wolbachia (groups A and B), suggesting 
that Wolbacia has infected sand flies on more than one occasion. Two 
distantly related sand fly species, Lutzomyia (Psanthyromyia) shannoi (
Dyar) and Lutzomyia (Nyssomyia) whitmani (Antunes & Coutinho), 
infected with an identical Wolbachia strain suggest a very recent 
horizontal transmission.




REQUEST: [ sandfly ]

(3 articles match this request. 2 articles matching other requests removed)



********************************************************************************************************************

 The following references are revised files and are brought to you in accordance
to license agreement with the NLM.

********************************************************************************************************************


PMID: 12399929
 

TITLE: Molecular evolution of the period gene in sandflies.

AUTHORS: C J Mazzoni, C A Gomes, N A Souza, R G de Queiroz, S C B Justiniano, R
D Ward, C P Kyriacou, A A Peixoto

AFFILIATION: Departamento de Bioquímica e Biologia Molecular, Fundação
Oswaldo Cruz, Av Brasil 4365--Manguinhos, CEP 21045-900, Rio de Janeiro,
Brazil.

REFERENCE: J Mol Evol 2002 Nov 55(5):553-62

The molecular evolution of the clock gene period was studied in 
Phlebotomine sandflies (Diptera: Psychodidae). Comparison of the 
synonymous and nonsynonymous substitution rates between sandflies and 
Drosophila revealed a significantly higher evolutionary rate in the 
latter in three of the four regions analyzed. The differences in rate 
were higher in the sequences flanking the Thr-Gly repetitive domain, a 
region that has expanded in Drosophila but remained stable and short in 
sandflies, a result consistent with the coevolutionary scenario proposed
 for this region of the gene. An initial phylogenetic analysis including
 eight neotropical sandfly species and one from the Old World was also 
carried out. The results showed that only the subgenus Nyssomyia is well
 supported by distance (neighbor-joining) and maximum parsimony analysis
. The grouping of the other species from the subgenus Lutzomyia and 
Migonei group shows very low bootstrap values and is not entirely 
consistent with classical morphological systematics of the genus 
Lutzomyia.















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