Immune response induced by New World Leishmania species in C57BL/6 mice.
In the present study, C57BL/6 mice were inoculated with metacyclic Leishmania amazonensis or L. braziliensis promastigotes. While these animals were capable of controlling the infection by L. braziliensis, they developed chronic lesions with elevated numbers of parasites when infected by L. amazonensis. The differences in parasite control were associated with a decreased production of IFN-gamma and TNF by lymph node cells from L. amazonensis-infected mice. Furthermore, these animals presented decreased spleen cell proliferation and activation of germinal centers. In addition, we compared the ability of these parasites to hydrolyze extracellular ATP and AMP. While the ATPase activity of both parasite species was similar, L. amazonensis promastigotes presented higher AMP hydrolytic activity. This increased activity may lead to an increased production of adenosine, which has been shown to present anti-inflammatory activity and may thus be involved in the establishment of the immunosuppression observed in mice infected by L. amazonensis.
Maioli
Tatiani Uceli
TU
Departamento de Ciências Biológicas, Instituto de Ciências Exatas e Biológicas/NUPEB, Universidade Federal de Ouro Preto, 35400-000, Ouro Preto, Minas Gerais, Brazil.
Takane
Erica
E
Arantes
Rosa Maria Esteves
RM
Fietto
Juliana Lopes Rangel
JL
Afonso
Luís Carlos Crocco
LC
D000249:Adenosine Monophosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D005260:Female; D006868:Hydrolysis; D066298:In Vitro Techniques; D007371:Interferon-gamma / Q000096:biosynthesis; D007892:Leishmania braziliensis / Q000276:immunology* / Q000378:metabolism / Q000472:pathogenicity; D007894:Leishmania mexicana / Q000276:immunology* / Q000378:metabolism / Q000472:pathogenicity; D016773:Leishmaniasis, Cutaneous / Q000276:immunology* / Q000469:parasitology / Q000473:pathology; D008213:Lymphocyte Activation; D051379:Mice; D008810:Mice, Inbred C57BL; D013154:Spleen / Q000473:pathology; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
D014409:Tumor Necrosis Factor-alpha; D000249:Adenosine Monophosphate; D007371:Interferon-gamma; D000255:Adenosine Triphosphate