Publications

[the isolation and immunochemical study of leishmania antigens].	the authors describe a procedure for producing the antigen by using a promastigotic suspension of the high-virulent inoculative strain leishmania major. a leishmania culture medium was improved to enhance the yield of parasites up to 1-3 billion cells in a flask. the grown culture was washed off with isotonic sodium chloride solution, from the medium residues and concentrated up to 1 billion cells per ml of the cvolume. the cell concentrate contained no rabbit blood additive, as evidenced by the ...	1994	7715549
evaluation of recombinant gp63, the major leishmania surface glycoprotein, as a diagnostic molecule for leishmaniasis in vervet monkeys.		1994	7709873
vaccination of the leishmania major susceptible balb/c mouse. i. the precise selection of peptide determinant influences cd4+ t cell subset expression.	balb/c mice are susceptible to cutaneous leishmaniasis upon infection with leishmania major while c57bl/6 are not. there is a major promastigote surface protease (psp or gp63) which is available in both native and recombinant forms, and for which the primary amino acid sequence is known. immunization with psp has been shown to offer some protection against challenge with the live organism. therefore, we attempted to develop a peptide vaccine with psp peptides. in the first experiments, recall pr ...	1994	7521670
leishmania major parasites share an epitope with the murine cd3-t cell receptor complex.	after immunization of balb/c mice with a low molecular mass fraction (frd; < or = 31 kda) isolated from a soluble extract of leishmania major promastigotes, a panel of monoclonal antibodies (mab) was obtained. one of these antibodies (mab 9c) recognized a cytosol-associated antigen from l. major of approximately 21 kda as shown by western blot and immunoprecipitation. in addition, mab 9c reacted with surface structures of murine splenic t cells and t cell clones. reactivity was confined to murin ...	1994	7510231
leishmania major-specific cd8+ t cells are inducers and targets of nitric oxide produced by parasitized macrophages.	lines of leishmania major-specific cd8+ t cells were derived from the lymph nodes and spleens of cba mice, immune following resolution of a primary infection, 7 days after secondary challenge with viable l. major. specific stimulation of these cd8+ t cells by bone marrow-derived macrophages infected with l. major led to the release of interferon-gamma by cd8+ t cells and nitric oxide by macrophages. interestingly, the nitric oxide released by bone marrow-derived macrophages down-regulated the pr ...	1994	7510243
cell-mediated responses of immunized vervet monkeys to defined leishmania t-cell epitopes.	a population of vervet monkeys was immunized with killed parasites and infected with leishmania major promastigotes either by needle or by infected-fly bite. the responses of recovered monkeys to mitogens, killed parasites, and molecularly defined t-cell epitopes were then compared with those of control animals. peripheral blood mononuclear cells (pbmc) from both naive and recovered animals proliferated strongly in response to both b- and t-cell mitogens, although the responses of the recovered ...	1994	7513306
tissue expression of inducible nitric oxide synthase is closely associated with resistance to leishmania major.	previous studies with inhibitors of inducible nitric oxide synthase (inos) suggested that high-output production of nitric oxide (no) is an important antimicrobial effector pathway in vitro and in vivo. here, we investigated the tissue expression of inos in mice after infection with leishmania major. immunohistochemical staining with an inos-specific antiserum revealed that in the cutaneous lesion and draining lymph nodes (ln) of clinically resistant mice (c57bl/6), inos protein is found earlier ...	1994	7520472
differential effects of blockade of cd28-b7 on the development of th1 or th2 effector cells in experimental leishmaniasis.	infection of inbred strains of mice with leishmania major is a well-characterized model for analysis of the development of effector cd4+ subsets of the th1 and th2 types in vivo. we co-administered a fusion protein, ctla4ig, that blocks the cd28-b7 costimulatory pathway important for optimal t cell activation, to assess the relative role for this pathway during maturation of th1 and th2 cells in vivo. surprisingly, ctla4ig administered within the first week of infection completely abrogated prog ...	1994	7523517
nitric oxide: cytokine-regulation of nitric oxide in host resistance to intracellular pathogens.	to discover how nitric oxide (no) synthesis is controlled in different tissues as cells within these tissues combat intracellular pathogens, we examined three distinctively different experimental murine models designed for studying parasite-host interactions: macrophage killing of leishmania major; nonspecific protection against tularemia (francisella tularensis) by mycobacterium bovis (bcg); and specific vaccine-induced protection against hepatic malaria with plasmodium berghei. each model para ...	1994	7537721
expression of murine vcam-1 in vitro and in different models of inflammation in vivo: correlation with immigration of monocytes.	vcam-1 (vascular cell adhesion molecule-1) is a cytokine-inducible adhesion molecule which is known to mediate adhesion of mononuclear cells to endothelial cells in vitro via binding to the integrin vla-4 (very late antigen-4). to further elucidate the role and regulation of vcam-1 in vivo, we compared in vitro and in vivo expression of vcam-1 in response to cytokines and investigated immunohistochemically the expression of vcam-1 in three murine models of experimental inflammation. these models ...	1994	7538407
parasites and t helper cell development: some insights.	five years after the initial observations implicating the t helper (th)-cell dichotomy (th1/th2) as the focal point in the immunoregulation of murine infection with leishmania major, investigation has shifted to the factors that govern the differentiation of a specific immune response from its pre-immune of undifferentiated state. in this article, steven reiner focuses on the most recent advances concerning the lineage commitment of mature th-cell populations, showing how new techniques [such as ...	1994	15275518
interleukin 12 and the regulation of cd4+ t-cell subset responses during murine leishmaniasis.	interleukin 12 is unique among cytokines in that it is capable of protecting genetically susceptible mice against progressive infection with leishmania major. because of the probable causal relationships between cd4(+) t-cell differentiation, cytokine production and disease outcome, this cytokine may prove useful as a component of cytokine-bosed therapies and thl-selective vaccines, as discussed here by frederick heinzel.	1994	15275471
pristane (2,6,10,14-tetramethyl-pentadecane) inhibits disease progression in leishmania-infected balb/c mice.	the course of leishmania infection in pristane-primed balb/c mice infected with either leishmania major or leishmania donovani was examined. pristane-primed l. donovani infected mice had spleen parasite-loads that were 13 times less than controls. likewise pristane-primed l. major infected animals had significantly smaller footpad lesion areas than controls. pristane-primed mice had an atypical haematology compared to controls. to the best of our knowledge, this is the first report to demonstrat ...	1994	12153340
evaluation of immune associated cells in lesions of l. major infected vervet monkeys (cercopithecus aethiops).	vervet monkeys were used to characterize immune associated cell types recruited into lesion sites as a result of experimental primary and secondary infections with leishmania major. a heavy cellular infiltration consisting primarily of cd8+ (cytotoxic/suppressor) t cells were observed in the lesions. a small number of b lymphocytes and nk cells were also stained. changes in cell type populations observed in the lesions were similarly reflected in the draining lymph nodes. studies from control si ...	1995	12160462
immunobiology of experimental cutaneous leishmaniasis.	the study of the murine model of infection with leishmania major is providing important insights into the understanding of the complex interactions between the host and intracellular pathogens. using this model system, basic research is actively leading to the identification of host factors promoting or circumventing the development of immunity to l. major. here, geneviève milon, giuseppe del giudice and jacques a. louis review recent results related to the characterization of immunological host ...	1995	15275334
leishmania major infection: the overture.	local infection of mice with leishmania major results in either healing or death depending on the preferential action of th1 or th2 t helper cells, respectively. although the parasite-induced t-cell responses and their consequences for the disease are well understood, relatively little is known about the initial events that kindle the adaptive immune response. werner salbach and tamás laskay here discuss how differences in parasites spreading from the site of infection to different immune organs ...	1995	15275406
altered immune responses in mice lacking inducible nitric oxide synthase.	nitric oxide (no) is important in many biological functions. it is generated from l-arginine by the enzyme no synthase (nos). the cytokine-inducible nos (inos) is activated by several immunological stimuli, leading to the production of large quantities of no which can be cytotoxic. to define the biological role of inos further, we generated inos mutant mice. these are viable, fertile and without evident histopathological abnormalities. however, in contrast to wild-type and heterozygous mice, whi ...	1995	7539113
[the possible use of gramicidin for the treatment of zoonotic cutaneous leishmaniasis].		1995	7539520
microscale analysis of glycosylphosphatidylinositol structures.		1995	7651181
effect of pge2 and of agents that raise camp levels on macrophage activation induced by ifn-gamma and tnf-alpha.	the effect of prostaglandin (pg) e2 on macrophage activation by interferon-gamma (ifn-gamma) and tumor necrosis factor-alpha (tnf-alpha) was evaluated. murine macrophages infected with leishmania enriettii or leishmania major were activated by exposure to ifn-gamma (10-50 u/ml) and tnf-alpha (30-3000 u/ml), leading to intracellular parasite destruction within 24-48 h. leishmanicidal activity was markedly increased when activation was performed in the presence of pge2 (10(-9)-10(-7) m) or arachid ...	1995	7543922
characterization of 'old world' leishmania species using amplified minicircle variable regions as molecular probes.		1995	7660454
the killing of leishmania major by human macrophages is mediated by nitric oxide induced after ligation of the fc epsilon rii/cd23 surface antigen.	serum ige concentrations and the expression of the low-affinity receptor for ige (fc epsilon rii/cd23) are increased in cutaneous leishmaniasis or after immune challenge with leishmania antigens. in vitro, the ligation of cd23 by ige-anti-ige immune complexes (ige-ic) or by anti-cd23 monoclonal antibody (mab) induces nitric oxide (no) synthase and the generation of various cytokines by human monocytes/macrophages. the present study shows that ige-ic, via cd23 binding, induce intracellular killin ...	1995	7544003
recombinant bcg expressing the leishmania surface antigen gp63 induces protective immunity against leishmania major infection in balb/c mice.	we have cloned and expressed the gp63 gene of leishmania major in bcg to develop a recombinant vaccine against zoonotic cutaneous leishmaniasis. two different expression systems were investigated. the first system consists of pan, a mycobacterium paratuberculosis promoter, which drives expression of orf2, an open reading frame in is900. this system allows the production of heterologous polypeptides as hybrids with the orf2 gene product. the second expression system relies on the production of an ...	1995	7551026
scid mice reconstituted with oct-2-deficient lymphocytes can cure leishmania major infection and generate normal antigen-specific t cells.		1995	7558177
cultivation of leishmania sp. in nutrient broth.	bone-marrow aspiration and biopsy material samples obtained from two patients, one diagnosed as visceral and other as cutaneous leishmaniasis, were inoculated in novy, mcneal, nicolle (nnn) medium and nutrient broth (nb), containing fetal calf serum (fcs), penicillin and streptomycine. both media were incubated at 27 degrees c for 10 days and observed daily for l. infantum and l. major promastigotes. promastigotes were observed in nutrient broth after the first day, while in nnn media after the ...	1995	7665939
experimental immunization against cutaneous leishmaniasis using leishmania major subcellular fractions alone or in combination with phlebotomus duboscqi gut antigens.	leishmania major-derived flagella and nuclear fractions, and a combination of flagella and sand fly gut antigens were assessed for protection against l. major infection in balb/c mice. mice immunized with flagella antigen developed a severe infection while nuclear fraction-immunized animals were partially protected at the onset of infection from week 1 to 4 post challenge. a combination/cock tail of flagella and sand fly gut antigens protected animals at a later stage from week 10 to 14 post-inf ...	1995	7588148
regulation of interleukin 12 p40 expression through an nf-kappa b half-site.	interleukin 12 (il-12) is an inducible cytokine composed of 35- and 40-kda subunits that is critical for promoting t helper type 1 development and cell-mediated immunity against pathogens. the 40-kda subunit, expressed by activated macrophages and b cells, is induced by several pathogens in vivo and in vitro and is augmented or inhibited by gamma interferon (ifn-gamma) or il-10, respectively. control of il-12 p40 expression is therefore important for understanding resistance and susceptibility t ...	1995	7565674
changes in lipophosphoglycan and gene expression associated with the development of leishmania major in phlebotomus papatasi.	stage-specific molecular and morphogenic markers were used to follow the kinetics of appearance, number, and position of metacyclic promastigotes developing during the course of l. major infection in a natural vector, phlebotomus papatasi. expression of surface lipophosphoglycan (lpg) on transformed promastigotes was delayed until the appearance of nectomonad forms on day 3, and continued to be abundantly expressed by all promastigotes thereafter. an epitope associate with arabinose substitution ...	1995	7567096
diversity among leishmania isolates from the sudan: isoenzyme homogeneity of l. donovani versus heterogeneity of l. major.	leishmania isolates from patients in the sudan suffering from either visceral or cutaneous leishmaniasis were characterized using a battery of 12 enzymes. aspartate aminotransferase separated the l. donovani isolates into 2 distinct zymodemes, but the overall results showed no significant geographical variation among l. donovani isolates. in contrast, the isolates of l. major were polymorphic, exhibiting differences in nucleoside hydrolase, 6-phosphogluconate dehydrogenase, superoxide dismutase, ...	1995	7570863
serodiagnosis of cutaneous leishmaniasis in jordan using indirect fluorescent antibody test and the enzyme-linked immunosorbent assay.	the usefulness of ifat and elisa, in the detection of antibodies to cutaneous leishmaniasis (cl) in jordanian cases was studied. serum samples were collected from three groups of confirmed or putative cl patients (n = 100), 132 healthy blood donors, 10 patients with pulmonary tuberculosis (tb), and 16 patients with typhoid fever (tf). antigens for both tests were prepared from promastigotes of a leishmania major isolate. at a serum dilution of respectively 1:16 and 1:100 both ifat and elisa had ...	1995	7676907
structure of leishmania lipophosphoglycan: inter- and intra-specific polymorphism in old world species.	the most abundant surface macromolecule on the promastigote stage of leishmanial parasites is a polymorphic lipophosphoglycan (lpg). we have elucidated the structures of two new lpgs, from leishmania tropica (lrc-l36) and l. aethiopica (lrc-l495), and investigated the nature of intra-specific polymorphism in the previously characterized lpg of l. major (lrc-l456 and -l580). these molecules contain a phosphoglycan chain, made up of repeating po4-6gal beta 1-4man units and a conserved hexaglycosyl ...	1995	7575413
protective vaccination with promastigote surface antigen 2 from leishmania major is mediated by a th1 type of immune response.	leishmania major promastigote surface antigen-2 complex (psa-2) comprises a family of three similar but distinct polypeptides. the three psa-2 polypeptides were purified from cultured promastigotes by a combination of detergent phase separation and monoclonal antibody affinity chromatography. intraperitoneal vaccination of c3h/he mice with psa-2 with corynebacterium parvum as an adjuvant resulted in complete protection from lesion development after challenge infection with virulent l. major. sig ...	1995	7591056
the sensitivity of leishmania species to aminosidine.	the aminoglycoside, aminosidine exhibited ed50s of between 1 and 5 microm against the amastigotes of leishmania major and leishmania tropica in mouse peritoneal macrophages whereas other strains causing new world cutaneous leishmaniasis such as leishmania braziliensis were more refractory. aminosidine was also active against all but one of the leishmania donovani strains tested and when combined with sodium stibogluconate, the drug showed marked potentiation against the amastigotes of l. donovan ...	1995	7592170
endogenous il-12 is required for control of th2 cytokine responses capable of exacerbating leishmaniasis in normally resistant mice.	we investigated the mechanisms by which treatment with anti-il-12 ab prevents cure of infection with leishmania major in resistant c57bl/6 mice. consistent with delayed production of il-12, anti-il-12 abs could be administered as late as 2 wk after infection to exacerbate disease. starting at 2 wk of infection, the cultured lymph node cells from mice treated with either polyclonal or monoclonal anti-il-12 abs persistently generated 3- to 10-fold more il-4 and il-10 in response to l. major ag com ...	1995	7608551
the rflp analysis of the beta-tubulin gene region in new world leishmania.	we have examined the similarities and differences in the organization of tubulin genes in new world leishmania by restriction endonuclease digestion of genomic dna and southern blot analysis, using heterologous and homologous tubulin gene probes. as judged by the hybridization pattern and the restriction fragment length polymorphism (rflp), there were large differences in both the restriction and hybridization patterns of the beta-tubulin sequences between stocks of the mexicana and braziliensis ...	1995	7609983
the regulation of immunity to leishmania major.	experimental infection with the intracellular protozoan leishmania major constitutes a particularly versatile model for assessing the role of cd4+ subset development in the host response to infectious disease. the association of th1 development with control of infection, and of th2 cell development with progressive disease, has been well established. the capacity to manipulate the outcome, using distinct immunologic interventions, in both genetically resistant and susceptible mice has identified ...	1995	7612219
protection against leishmania major infection in genetically susceptible balb/c mice by gp63 delivered orally in attenuated salmonella typhimurium (aroa- arod-).	the gene encoding the leishmania major (l. major) promastigote surface glycoprotein, gp63, was introduced into the salmonella typhimurium (s. typhimurium) aroa- arod- live oral vaccine strain brd509 and expressed under the control of a constitutive tac promoter in plasmid pkk233-2. this construct (gid101) expressed gp63 in vitro and was used to immunize highly susceptible balb/c mice by the oral route. the plasmid was relatively stably inherited by bacteria growing or persisting in the mesenteri ...	1995	7635511
a member of the clpb family of stress proteins is expressed during heat shock in leishmania spp.	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 ...	1995	7637691
identification of intra- and interspecific leishmania genetic polymorphisms by arbitrary primed polymerase chain reactions and use of polymorphic dna to identify differentially regulated genes.	arbitrary primed polymerase chain reactions (ap-pcr) were used to amplify different polymorphic genomic dna fragments from various old world leishmania species. using four 10-mer ap primers, geographic isolates of l. donovani and various old world species of leishmania could be readily distinguished from one another by the pattern of amplified dna products. our studies confirmed two important characteristics of ap-pcr: its abilities to amplify a consistent pattern of dna fragments from the genom ...	1995	7624284
in vivo evaluation of immune responses in leishmaniasis: the use of cross-species leishmanin preparations for skin testing.	skin test reactivity to two commercial preparations of leishmania major leishmanin was evaluated in leishmaniasis patents from ethiopia (l. aethiopica) and nicaragua (probably l. braziliensis complex). the purpose of using different preparations of l. major was to evaluate whether l. major skin test antigens could generally be used to detect leishmaniasis due to l. aethiopica and l. braziliensis. one preparation was superior in identifying the majority (83-90%) of confirmed cases of local cutane ...	1995	7625529
sand fly vector saliva selectively modulates macrophage functions that inhibit killing of leishmania major and nitric oxide production.	the saliva of phlebotomus papatasi, a sand fly vector for leishmania major, contains a factor that exacerbates leishmaniasis and may be required for the establishment of infection with leishmania in nature. we have examined the effect of sand fly saliva on various macrophage functions in vitro. our data demonstrate that although saliva does not alter uptake of l. major by macrophages, it inhibits the ability of ifn-gamma to activate macrophages to kill the intracellular parasite. this inhibition ...	1995	7561045
molecular comparison of the mitochondrial and cytoplasmic hsp70 of trypanosoma cruzi, trypanosoma brucei and leishmania major.	we compared the expression and localization of the mitochondrial and cytoplasmic hsp70 of the protozoans trypanosoma cruzi, trypanosoma brucei and leishmania major. the mitochondrial protein is encoded by multiple mrna in all species, while the cytoplasmic protein is encoded by a single mrna. in all three species, the mitochondrial hsp70 is concentrated in the kinetoplast, a submitochondrial structure that houses the unusual dna (kdna) that characterizes this group of organisms, while the cytopl ...	1995	7581323
cloning and characterization of the ribosomal l11 gene from leishmania spp.		1995	7477109
development of a safe live leishmania vaccine line by gene replacement.	vaccination with live leishmania major has been shown to yield effective immunization in humans; however, this has been discontinued because of problems associated with virulence of the available vaccine lines. to circumvent this, we tested the ability of a dhfr-ts- null mutant of l. major, obtained by gene targeting, to infect and then to vaccinate mice against challenge with virulent l. major. survival and replication of dhfr-ts- in macrophages in vitro were dependent upon thymidine, with para ...	1995	7479765
efficacy of the herbicide trifluralin against four p-glycoprotein-expressing strains of leishmania.	drug resistance has emerged as a major obstacle to chemotherapy for many infectious diseases. trifluralin, an antimicrotubule herbicide, is a new experimental drug for treatment of leishmaniasis. here, we found that it was effective against two strains of leishmania that express the multidrug-resistant genes ldmdr1 and lmpgpa and two strains that express proteins that are immunologically cross-reactive with mammalian p glycoproteins. these results suggest that trifluralin is not subject to count ...	1995	7492115
studies on zoonotic cutaneous leishmaniasis among a group of temporary workers in north sinai governorate, egypt.	leishmaniasis (cutaneous, cl. and visceral, vl.) is an increasing public health problem in the mediterranean region. from a practical point of view, zcl is the most important and distributed form in egypt. consequently, it was aimed to study the status of zcl among a group of temporary workers in north sinai governorate. the results showed that (i) rodent populations are more or less common in al arish city (rattus rattus and r. norvegicus), bir lehfan (gerbillus pyramidum) and abo oegela (g. py ...	1995	7602176
[leishmaniasis: new diagnostic approaches].		1995	7582649
evidence from genotypic and phenotypic markers that an attenuated line outgrows a virulent one in a mixed population of leishmania major promastigotes cultured in vitro.	two cloned lines of leishmania major promastigotes, one attenuated (co1h) and one virulent (co1r), differing in molecular karyotype and expression of the major surface glycoprotein (gp63), were mixed to produce two heterogeneous populations: mp-1 (100 co1r promastigotes/co1h promastigote); and mp-2 (10,000 co1r promastigotes/co1h promastigote). the mixed populations were cultured for 1 month in vitro in ho-mem medium and sub-samples taken on days 4 and 30 were subjected to electrophoresis so tha ...	1995	7495361
determinant flanking regions and the design of appropriate vaccines.		1995	7625680
location in the source chromosome of the 180-kb minichromosome of leishmania major and characterization of the novel junction.	the 180-kb ld1 minichromosome of leishmania major (m180) is a large inverted duplication which arises spontaneously from a megabasic chromosome. in this work this locus has been located in the source chromosome at a telomeric position. both the novel junction created in the middle of the minichromosome, as well as its counterpart region in the source chromosome were cloned and sequenced. two inverted repeats, which could give rise to two imperfect stem-loops, and an a + t-rich dna sequence were ...	1995	7477097
the cation-independent mannose-6-phosphate receptor binds to soluble gpi-linked proteins via mannose-6-phosphate.	the cation-independent mannose-6-phosphate/insulin-like growth factor ii receptor has been observed to bind to soluble forms of glycosyl-phosphatidylinositol-linked molecules, one of mammalian origin (rat thy-1) and two of protozoan origins. of the two phosphate groups found on the soluble forms of the protozoan glycosyl-phosphatidylinositol-linked molecules: (i) the internal mannose-6-phosphate diester (which forms a part of the ethanolamine bridge) and (ii) the inositol-1,2 cyclic phosphate gr ...	1995	7607332
comparison of new and old world leishmanins in an endemic region of brazil.	the control of leishmaniasis depends on a knowledge of the magnitude of the disease and of exposure to it. delayed-type hypersensitivity testing can detect prior exposure to the parasite, but there is little agreement regarding the choice of an antigen for such testing. new and old world leishmanins were tested in a study of patients with confirmed prior cutaneous leishmaniasis (cl), patients with confirmed prior american visceral leishmaniasis (avl), and controls from areas in espírito santo, b ...	1995	7620013
ubiquinone biosynthesis in leishmania major promastigotes.	promastigotes of leishmania major contain a ubiquinone which has a side chain made up of nine isoprene subunits (uq9). incorporation of radioactivity from [14c] acetate and [14c] mevalonate into ubiquinone as well as the identification of hydroxymethylglutaryl coenzyme a reductase (hmg coa reductase), and mevalonate kinase indicate that the isoprenoid portion of the molecule is synthesized by the acetate-mevalonate pathway as in mammalian cells. incorporation of [14c] tyrosine into ubiquinone is ...	1995	7601585
leishmania major: in vitro ultrastructural study of the paraxial rod of promastigotes.	the flagellum of leishmania major promastigotes has an intraflagellar structure known as the paraxial rod (par) which extends from a point halfway in the flagellar pocket to the tip of the flagellum, lying opposite the axonemal microtubule doublets 4-7. an expansion of the axonemal plasma membrane envelops the par and may provide desmosomal attachment at the orifice of the flagellar pocket. the complex organization of the 4-6 nm thick filaments in the par was studied by us in cross, oblique, lon ...	1995	7635620
high constitutive levels of heat-shock proteins in human-pathogenic parasites of the genus leishmania.	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 s ...	1995	7646449
amino acid sequence of the ribosomal protein hs23 from the halophilic haloarcula marismortui and homology studies to other ribosomal proteins.	the ribosomal protein hs23 from the 30s subunit of the extreme halophilic haloarcula marismortui, belonging to the group of archaea, was isolated either by rp-hlplc or two-dimensional polyacrylamide gel electrophoresis. the complete amino acid sequence was determined by automated n-terminal microsequencing. the protein consists of 123 residues with a corresponding molecular mass of 12,552 da as determined by electrospray mass spectroscopy; the pi is 11.04. homology studies reveal similarities to ...	1995	7662106
interleukin 12 signaling in t helper type 1 (th1) cells involves tyrosine phosphorylation of signal transducer and activator of transcription (stat)3 and stat4.	interleukin 12 (il-12) initiates the differentiation of naive cd4+ t cells to t helper type 1 (th1) cells critical for resistance to intracellular pathogens such as leishmania major. to explore the basis of il-12 action, we analyzed induction of nuclear factors in th1 cells. il-12 selectively induced nuclear dna-binding complexes that contained stat3 and stat4, recently cloned members of the family of signal transducers and activators of transcription (stats). while stat3 participates in signali ...	1995	7722452
activity of pentostam (sodium stibogluconate) against cutaneous leishmaniasis in mice treated with neutralizing anti-interferon-gamma antibody.	studies with leishmania donovani in the mouse have demonstrated that an intact t cell compartment is required for effective anti-leishmanial therapy using pentavalent antimony compounds such as pentostam (sodium stibogluconate), suggesting that the in vivo efficacy of drug treatment is at least partially immune-based. similarly, leishmania-infected, immunodeficient human patients including those with acquired immunodeficiency syndrome (aids) generally relapse following therapy with antimonials. ...	1995	7625533
prediction of omega site in nascent precursor of glycosylphosphatidylinositol protein.		1995	7651179
the complete sequence of leishmania rna virus lrv2-1, a virus of an old world parasite strain.	a complete cdna sequence is reported for lrv2-1, the first leishmania rna virus known to infect an old world parasite, leishmania major. sequence analyses show that lrv2-1 differs significantly from members of the lrv1 genus which infect new world parasites. the data support a view that transmission of lrv is strictly vertical and suggest that lrv predate the divergence of old and new world parasites. as a consequence of this divergence, conserved features can be identified for the first time in ...	1995	7676652
glycoinositolphospholipids of leishmania major inhibit nitric oxide synthesis and reduce leishmanicidal activity in murine macrophages.	murine macrophages express high levels of inducible nitric oxide (no) synthase and produce large amounts of nitric oxide when activated with interferon-gamma and lipopolysaccharide in vitro. nitric oxide is a mediator of a variety of biological functions including microbicidal activity against the protozoan parasite leishmania species. glycoinositolphospholipids (gipl) are the predominant surface glycolipids in both developmental stages of leishmania major. we report here that gipl can inhibit t ...	1995	7705404
induction of a th2 population from a polarized leishmania-specific th1 population by in vitro culture with il-4.	the infection of mice with leishmania major parasite induces polarized th1 and th2 responses that cannot be significantly changed in vivo after 2 to 3 wk of infection by using either cytokines or anti-cytokine abs. it is not clear, however, whether the t cell populations are irreversibly differentiated or whether the inability to modify the cytokine production reflects inefficiencies in the experimental treatments or complications of the infection itself. to study this further, we have cultured ...	1995	7706719
expansion of gamma delta+ t cells in balb/c mice infected with leishmania major is dependent upon th2-type cd4+ t cells.	t cells belong to either the alpha beta+ or gamma delta+ lineage as defined by their antigen receptor. although both t-cell subsets have been shown to be involved in the immune response to the parasite leishmania major, very little is known about possible interactions between these two populations. in this study, using a mouse model of infection with l. major, we showed that expansion of a subset of gamma delta+ t cells in vivo is dependent upon the presence of alpha beta+ cd4+ t cells. moreover ...	1995	7622222
dendritic cells in leishmania major-immune mice harbor persistent parasites and mediate an antigen-specific t cell immune response.	upon infection with leishmania major, a cause of human cutaneous leishmaniasis, mice of resistant strains are able to control the infection, with lesions resolving spontaneously. a long-lasting cell-mediated immunity protects them from reinfection. nevertheless, small numbers of viable parasites persist in the lymph nodes of these mice. we have recently documented that, in addition to macrophages, epidermal langerhans cells can ingest l. major. furthermore, langerhans cells have the unique abili ...	1995	7705398
the role of the innate immune response in th1 cell development following leishmania major infection.	infection of mice with the protozoan parasite leishmania major is an established model with which to study the in vivo development of cd4+ th cell subsets. interferon-gamma (ifn-gamma), produced by natural killer (nk) cells (asgm1+, cd4-, cd8-, cd3-), regulates cd4+ t cell subset development and early resistance to l. major. rapid th1 cell development and resistance to infection occur in mice that develop an nk cell response early after infection (c3h and immunized balb/c mice), whereas mice tha ...	1995	7722408
diffusely disseminated cutaneous leishmania major infection in a child with acquired immunodeficiency syndrome.		1995	7761198
modulation of specific t cell responses by concurrent infection with leishmania major and lp-bm5 murine leukemia viruses.	c57bl/6 mice infected with a murine leukemia virus (mulv) mixture designated lp-bm5 develop an immunodeficiency syndrome termed maids, characterized by a variety of t and b cell abnormalities, including elevated levels of ige, suggesting that il-4 expression is increased in these animals. it has been suggested that the immunodeficiency associated with maids is caused by a conversion of immune responses normally characterized by th1 development towards a th2-dominated response. mice of the same s ...	1995	7718509
effect of iron chelation on the in-vitro growth of leishmania promastigotes.	the development of vaccines and drugs to control leishmaniasis is urgently needed. the presence of a leishmania transferrin receptor on the parasite suggests that an adequate supply of iron is needed for the life cycle of leishmania. we have investigated the effect of iron deprivation on the growth of leishmania promastigotes in vitro using an iron chelation approach. all chelators tested reduced the rate of promastigote multiplication in a dose-dependent fashion, whereas referrated ones did not ...	1995	7768775
protective effect of leflunomide on the natural course of leishmania major-induced disease in genetically susceptible balb/c mice.	leflunomide has been reported as an immunomodulating agent which acts on a variety of cells including t- and b-lymphocytes. cd4+ t-lymphocytes are essential for the type of disease that develops after infection with the protozoan parasite leishmania major. a variety of immunological interventions has been shown to modulate disease development. therefore, the effect of leflunomide on the development of parasite-induced lesions and the ensuing immune response was investigated in genetically suscep ...	1995	7499024
mastomys natalensis and tatera gambiana as probable reservoirs of human cutaneous leishmaniasis in nigeria.	leishmania sp. was isolated from the livers and spleens of 4 of 56 mastomys natalensis and one of 21 tatera gambiana in keana district, nigeria; none of the rodents had cutaneous lesions. parasites were not found in 42 rattus rattus. experimentally infected mice developed cutaneous lesions characteristic of l. major infection. the organisms could not be cultivated in vitro.	1995	7747299
conservation among old world leishmania species of six physical linkage groups defined in leishmania infantum small chromosomes.	we have characterised 49 dna probes specific for each of the six smallest chromosomes in leishmania infantum and have examined the allocation of these probes in the molecular karyotypes of the other old world leishmania species leishmania donovani, leishmania major, leishmania tropica and leishmania aethiopica. these 49 probes define 6 physical linkage groups in the molecular karyotypes of various strains of l. infantum. 40 of these probes hybridise in the other old world leishmania species and ...	1995	7723776
interleukin 12 is effective treatment for an established systemic intracellular infection: experimental visceral leishmaniasis.	when administered at or near the initiation of experimental intracellular infection caused by leishmania major, toxoplasma gondii, or cryptococcus neoformans, treatment with the immuno-regulatory cytokine interleukin 12 (il-12), induces protective antimicrobial activity. in contrast, once infections are established, il-12 exerts considerably less or no effect in the face of a suppressive th2 cell-associated response (l. major) or rapidly progressive fatal infection (t. gondii). to test the effic ...	1995	7807019
early parasite containment is decisive for resistance to leishmania major infection.	we investigated the early spread of leishmania major in various mouse strains. in balb/c mice, which are extremely vulnerable to l. major infection, the parasites disseminated within 10-24 h from the site of subcutaneous footpad infection in to the popliteal lymph node, spleen, lung, liver and bone marrow. application of recombinant (r)il-12 prior to infection prevented the early dissemination of parasites into visceral organs and the animals healed the infection. in three mouse strains tested, ...	1995	7664785
transgenic mice expressing high levels of soluble tnf-r1 fusion protein are protected from lethal septic shock and cerebral malaria, and are highly sensitive to listeria monocytogenes and leishmania major infections.	mice bearing a transgene coding for a soluble tumor necrosis factor receptor type 1 (tnfr1)-fcigg3 fusion protein and placed under the control of the alpha-1-antitrypsin gene promoter were generated. depending on the mouse line, blood levels of the protein ranged from 25 ng/ml to over 100 micrograms/ml; this level of expression was most often transmitted to the transgene-bearing progeny as a relatively stable feature. high-expressor mice were completely resistant to lipopolysaccharide-induced sh ...	1995	7664802
complement-mediated lysis and infectivity for mouse macrophages and sandflies of virulent and attenuated leishmania major promastigotes varying in expression of the major surface protease and lipophosphoglycan.	the infectivity to mouse macrophages and sandflies, the expression and enzymatic activity of the major surface glycoprotein (gp63), the developmental modification of lipophosphoglycan (lpg) and three metacyclogenesis markers (promastigote body size, lectin agglutination and complement resistance) were compared in four related leishmania major promastigote lines. the lines, which differed in their virulence for balb/c mice, were examined in both logarithmic and stationary phase. although the two ...	1995	7668915
switch from a type 2 to a type 1 t helper cell response and cure of established leishmania major infection in mice is induced by combined therapy with interleukin 12 and pentostam.	successful treatment in allergic, autoimmune, and infectious diseases often requires altering the nature of a detrimental immune response mediated by a particular cd4+ t helper (th) cell subset. while several factors contribute to the development of cd4+ th1 and th2 cells, the requirements for switching an established response are not understood. here we use infection with leishmania major as a model to investigate those requirements. we report that treatment with interleukin 12 (il-12), in comb ...	1995	7724530
crystallization and preliminary x-ray diffraction studies of leishmanolysin, the major surface metalloproteinase from leishmania major.	the membrane-bound gpi-anchored zinc metalloproteinase leishmanolysin purified from leishmania major promastigotes has been crystallized in its mature form. two crystal forms of leishmanolysin have been grown by the vapor diffusion method using 2-methyl-2,4-pentanediol as the precipitant. macroseeding techniques were employed to produce large single crystals. protein microheterogeneity in molecular size and charge was incorporated into both crystal forms. the tetragonal crystal form belongs to t ...	1995	7675788
expression cloning of a protective leishmania antigen.	parasite-specific cd4+ t cells have been shown to transfer protection against leishmania major in susceptible balb/c mice. an epitope-tagged expression library was used to identify the antigen recognized by a protective cd4+ t cell clone. the expression library allowed recombinant proteins made in bacteria to be captured by macrophages for presentation to t cells restricted to major histocompatibility complex class ii. a conserved 36-kilodalton member of the tryptophan-aspartic acid repeat famil ...	1995	7725103
a randomized, placebo-controlled trial in tunisia treating cutaneous leishmaniasis with paromomycin ointment.	a randomized, placebo-controlled, double-blind trial was carried out in 1992 in central tunisia to assess the tolerability and efficacy of paromomycin ointment against zoonotic cutaneous leishmaniasis caused by leishmania major. one hundred fifteen patients, 2--60 years of age, with a single lesion of parasitologically confirmed cutaneous leishmaniasis, were included in the trial. the ointment was applied twice a day from day 1 through day 14. clinical and parasitologic evaluations of lesions we ...	1995	7677218
biosynthesis of the glycolipid anchor of lipophosphoglycan and the structurally related glycoinositolphospholipids from leishmania major.	the major macromolecule on the surface of the protozoan parasite leishmania major is a lipophosphoglycan (lpg) which contains a glycosylphosphatidylinositol glycolipid anchor. this parasite also synthesizes a complex family of abundant low-molecular-mass glycoinositolphospholipids (gipls) which are structurally related to the lpg anchor. in this study, l. major promastigotes were metabolically labelled with [3h]glcn, and the kinetics of incorporation into free glycolipids and the lpg anchor foll ...	1995	7755587
the gene encoding streptothricin acetyltransferase (sat) as a selectable marker for leishmania expression vectors.	the plex series of vectors was developed for the stable expression of exogenous genes in the protozoan parasite leishmania. these puc-based constructs contain one of three independent selectable markers and a multiple cloning site inserted between the upstream and downstream untranslated regions of the previously cloned leishmania major hexbp gene. selection was based on resistance to the aminoglycosides, hygromycin b and neomycin, and to nourseothricin, a novel independent selectable marker for ...	1995	7737509
dichotomy of the t cell response to leishmania antigens in patients suffering from cutaneous leishmaniasis; absence or scarcity of th1 activity is associated with severe infections.	the t cell response was studied in 25 patients suffering from cutaneous leishmaniasis caused by leishmania major with severe (n = 10) and mild (n = 15) disease manifestations. peripheral blood mononuclear cells (pbmc) from the patients were activated by sonicates of leishmania promastigotes (lmp) and amastigotes (lda), and the surface protease gp63. the proliferative responses to leishmania antigens were lower in patients with severe disease than in patients with mild disease (p = 0.01-0.05), an ...	1995	7743662
il-12 is required for natural killer cell activation and subsequent t helper 1 cell development in experimental leishmaniasis.	infection of mice with the protozoan leishmania major is an established in vivo model for the definition of factors that contribute to cd4+ t helper cell subset development. in the current study, a central role for il-12 in directing both the innate and adaptive immune responses to l. major is established. we show that in vivo neutralization of il-12 eliminates the nk cell cytotoxic response and ifn-gamma production by lymph node cells from 2-day l. major-infected c3h mice. moreover, anti-il-12 ...	1995	7730635
response of scid mice to establishment of leishmania major infection.	the initiation of leishmania major infection in susceptible balb/c mice is regulated by interferon-gamma (ifn-gamma). to examine further the mechanisms of ifn-gamma-dependent regulation of the establishment of l. major, we studied the characteristics of the infection in severe combined immunodeficient (scid) mice. in the first 2 weeks of infection, we observed a delay in the development of the lesions in the footpads and lower numbers of parasites in scid compared with balb/c mice. by week 5 aft ...	1995	7774053
the hsp83 intergenic region in leishmania: conservation of sequence and function across two species.		1995	7821406
stimulation of b-cell lymphopoiesis by interleukin-7 leads to aggravation of murine leishmaniasis.	the effect of recombinant interleukin-7 (il-7) on the clinical course of murine leishmaniasis and the development of the accompanying immune response was investigated. previously, il-7 has been shown to possess stimulatory capacity for different cell types of the immune and haematopoietic system critically involved in the defence against leishmania major (l. major), such as macrophages which are activated for the elimination of the parasite by il-7. in contrast to these in vitro data, the presen ...	1995	7751025
protection against leishmaniasis by injection of dna encoding a major surface glycoprotein, gp63, of l. major.	cdna encoding the highly conserved major surface glycoprotein, gp63, of leishmania major was cloned, together with a signal sequence, into an eukaryotic expression vector, pcdnai, which carries the human cytomegalovirus (cmv) promoter. this construct, pcmv/glycoprotein 63 (gp63), when injected into the skeletal muscle of balb/c mice expressed sustained levels of gp63 in the muscle tissue for at least 40 days. spleen and lymph node cells from the immunized mice produced significant amounts of int ...	1995	7750991
infection of human and murine macrophages with leishmania major is associated with early parasite heat shock protein synthesis but fails to induce a host cell stress response.	heat shock/stress proteins (hsp) represent the most conserved proteins expressed in prokaryotes and eukaryotes. these constitutive and inducible proteins function as molecular chaperones and are part of virulence factors. they participate in self/non-self discrimination and may protect phagocytes from the toxic effects of the reactive oxygen species generated by these cells during bacterial phagocytosis and infection. in this study, we investigated the early stress response of host cells [either ...	1995	7768547
[a comparison of the growth of leishmania major, l. turanica and l. gerbilli on nnn medium].	leishmania promastigotes grew in the nnn medium with medium-199 as a liquid phase. the nnn medium was prepared with agar bases of the following firms: sigma, oxoid, difco, medbioprom (russia). growth characteristics were examined with the following indices: specific growth rate (r), reduplication time (t), reproductive rate (k). the investigations have shown that the kind of agar base has the most influence on the r and t of l.turanica and l.gerbelli and on the k of l.major. the greatest differe ...	1995	7770011
the pathology of cutaneous leishmaniasis due to leishmania major in sudan.	the pathology of cutaneous leishmaniasis in sudan, where the disease is caused by leishmania major, was studied by light and electron microscopy. lesions were classified into four distinct groups based on the ratio of different cell types, especially lymphocytes, macrophages, and plasma cells in the inflammatory infiltrate, and the formation of compact epithelioid granulomas or the presence of necrosis. in the lesions, there was a positive correlation between the number of lymphocytes and the nu ...	1995	7771611
class ii major histocompatibility complex-deficient mice initially control an infection with leishmania major but succumb to the disease.	class ii major histocompatibility complex (mhc)-deficient (h-2b) mice do not express i-a or i-e molecules and, as a result, do not develop cd4 cells. thus, they represent the ideal model for examining the importance of cd4 cells and mhc class ii molecules in resistance to infection with leishmania major and the capacity of mhc class i-restricted t cells to mediate resistance to l. major. class ii mhc-deficient mice and control (c57bl/6, normal and nude) mice were infected with l. major. although ...	1995	7751707
antigen-presenting cells in human cutaneous leishmaniasis due to leishmania major.	in this study biopsies from skin lesions and draining lymph nodes of patients suffering from cutaneous leishmaniasis caused by leishmania major were examined by immunohistochemistry, and by light and electron microscopy to identify the types of antigen-presenting cells (apc) and their location. apc, identified morphologically and by their expression of specific cell markers, included langerhans cells, macrophages, follicular dendritic cells, and interdigitating reticulum cells of the paracortex ...	1995	7882568
lipophosphoglycan blocks attachment of leishmania major amastigotes to macrophages.	promastigotes of the intracellular protozoan parasite leishmania major invade mononuclear phagocytes by a direct interaction between the cell surface lipophosphoglycan found on all leishmania species and macrophage receptors. this interaction is mediated by phosphoglycan repeats containing oligomers of beta (1-3)gal residues specific to l. major. we show here that although amastigotes also use lipophosphoglycan to bind to both primary macrophages and a cell line, this interaction is independent ...	1995	7806383
trypanosomatid cysteine protease activity may be enhanced by a kininogen-like moiety from host serum.	african trypanosomes contain cysteine proteases (trypanopains) the activity of which can be measured by in vitro digestion of fibrinogen, after electrophoresis in fibrinogen-containing sds/polyacrylamide gels. when assessed by this procedure, trypanopain from trypanosoma brucei (trypanopain-tb) is estimated to have a molecular mass of 28 kda. however, two additional bands of trypanopain activity (87 kda and 105 kda) are observed if serum is added to the trypanopain before electrophoresis. format ...	1995	7832773
t cell genetic background determines default t helper phenotype development in vitro.	a host's ability to resist certain pathogens such as leishmania major can depend upon the phenotype of t helper (th) subset that develops. different murine genetic backgrounds are known to significantly alter the direction of th subset development, although the cellular basis of this influence is poorly understood. to examine the basis of this effect we used an in vitro alpha/beta-t cell receptor (tcr) transgenic system for analysis of th phenotype development. to control for tcr usage, we deriv ...	1995	7836924
t cell and non-t cell compartments can independently determine resistance to leishmania major.	in experimental murine cutaneous leishmaniasis caused by leishmania major (lm), the cellular determinants governing development of protective or exacerbative t cells are not well understood. we, therefore, attempted to determine the influence of t cell and non-t cell compartments on disease outcome. to this end, t cell chimeric mice were constructed using adult thymectomized lethally irradiated, bone marrow-reconstituted (atxbm) animals of genetically resistant, c57bl/6, or susceptible, balb/c, ...	1995	7869047
interleukin-4 and interferon-gamma production by leishmania stimulated peripheral blood mononuclear cells from nonexposed individuals.	interferon-gamma (ifn-gamma) and interleukin-4 (il-4) production by leishmania reactive peripheral blood mononuclear cells (pbmc) from non-exposed individuals was investigated. ifn-gamma was measured in culture supernatants after antigen stimulation. for the measurement of il-4, antigen stimulated cells were pulsed with pma and ionomycin before il-4 release was measured. l. donovani and l. major antigens induced il-4 production (105-1748 pg/ml) in 13 and seven cultures, and ifn-gamma production ...	1995	7899822
mice from a genetically resistant background lacking the interferon gamma receptor are susceptible to infection with leishmania major but mount a polarized t helper cell 1-type cd4+ t cell response.	mice with homologous disruption of the gene coding for the ligand-binding chain of the interferon (ifn) gamma receptor and derived from a strain genetically resistant to infection with leishmania major have been used to study further the role of this cytokine in the differentiation of functional cd4+ t cell subsets in vivo and resistance to infection. wild-type 129/sv/ev mice are resistant to infection with this parasite, developing only small lesions, which resolve spontaneously within 6 wk. in ...	1995	7869054
bicarbonate ions and ph regulation of leishmania major promastigotes.	leishmania major promastigotes are parasites endowed with a plasma membrane electrogenic h+ pump and anionic channels. these systems have been thought to contribute to ph homeostasis of parasites and environmental adaptation by mediating extrusion of protons which are either generated metabolically or result from exogenous acid loads. in this work we show that hco-3 transport plays a physiological role in supporting ph regulation of parasites. intracellular ph (phi) and the membrane potential (v ...	1995	7890030
chloride conductive pathways which support electrogenic h+ pumping by leishmania major promastigotes.	the proton extrusion mechanisms of leishmania promastigotes were studied in terms of electrogenic movements of protons and anions (cl- and hco3-). changes in membrane potential (vm) and intracellular ph (phi) were monitored fluorimetrically with the potential sensitive dye bis-oxonol and the ph-sensitive dye tetraacethoxymethyl 2',7'-bis-(carboxyethyl)-5,6-carboxyfluorescein, respectively. in nominal bicarbonate-free medium (phe 7.4, 28 degrees c), vm and phi of leishmania promastigotes were mai ...	1995	7890641