Characterization of T cell responses to purified leishmania antigens in subjects infected with Leishmania chagasi.
T cell responses to lipophosphoglycan-associated protein (LPG-AP) and the rgp63 antigens were studied in subjects with either asymptomatic L. chagasi infection or cured visceral leishmaniasis. The [3H]-thymidine uptake of lymphocytes stimulated with LPG-AP and rgp63 (mean +/- SD) was 14275 +/- 5048 and 3523 +/- 1678 cpm, respectively, for subjects with asymptomatic L. chagasi infection and 20046 +/- 5102 and 5086 +/- 3500 cpm, respectively, for subjects cured of visceral leishmaniasis. The responses to LPG-AP in both asymptomatic and cured visceral leishmaniasis were higher (P < 0.01) than those observed with rpg63. LPG-AP induced IFN-gamma production in all subjects studied, while rgp63 did not induce lymphocyte proliferation or IFN-gamma production in the majority of the subjects tested. IFN-gamma levels in cultures stimulated with LPG-AP were 103 +/- 81 pg/ml in individuals with asymptomatic L. chagasi infection and 127 +/- 123 pg/ml in subjects cured of visceral leishmaniasis. IFN-gamma levels in cultures stimulated with LPG-AP from subjects with asymptomatic L. chagasi infection were comparable to those observed in subjects cured of visceral leishmaniasis (P > 0.05). These data indicate that LPG-AP is recognized and induces T cell proliferation and IFN-gamma production in subjects with protective immune response against Leishmania chagasi.
Vinhas
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Serviço de Imunologia, Hospital Universitário Prof. Edgard Santos, Universidade Federal da Bahia, Salvador, Brasil.
Freire
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Bacellar
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O
Cunha
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Rocha
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Carvalho
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EM
D000293:Adolescent; D000328:Adult; D000818:Animals; D000953:Antigens, Protozoan / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006028:Glycosphingolipids / Q000276:immunology; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis; D018314:Leishmania infantum / Q000276:immunology*; D007898:Leishmaniasis, Visceral / Q000276:immunology*; D008213:Lymphocyte Activation / Q000276:immunology; D008297:Male; D008666:Metalloendopeptidases / Q000276:immunology; D008875:Middle Aged; D015800:Protozoan Proteins / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism
D000953:Antigens, Protozoan; D006028:Glycosphingolipids; D015800:Protozoan Proteins; C008290:lipophosphonoglycan; D007371:Interferon-gamma; D008666:Metalloendopeptidases; C055146:glycoprotein gp63, Leishmania