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A Leishmania infantum cytosolic tryparedoxin activates B cells to secrete interleukin‐10 and specific immunoglobulin
Author(s) -
Menezes Cabral Sofia,
Leal Silvestre Ricardo,
Moreira Santarém Nuno,
Costa Tavares Joana,
Franco Silva Ana,
CordeirodaSilva Anabela
Publication year - 2008
Publication title -
immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.297
H-Index - 133
eISSN - 1365-2567
pISSN - 0019-2805
DOI - 10.1111/j.1365-2567.2007.02725.x
Subject(s) - biology , antibody , immune system , secretion , cytokine , immunoglobulin e , population , leishmania infantum , antigen , microbiology and biotechnology , immunology , biochemistry , visceral leishmaniasis , leishmaniasis , demography , sociology
Summary The immune evasion mechanisms of pathogenic trypanosomatids involve a multitude of phenomena such as the polyclonal activation of lymphocytes, cytokine modulation and the enhanced detoxification of oxygen reactive species. A trypanothione cascade seems to be involved in the detoxification process. It was recently described and characterized a tryparedoxin ( Li TXN1) involved in Leishmania infantum cytoplasmatic hydroperoxide metabolism. Li TXN1 is a secreted protein that is up‐regulated in the infectious form of the parasite, suggesting that it may play an important role during infection. In the present study, we investigated whether recombinant Li TXN1 (r Li TXN1) affects T‐ and B‐cell functions in a murine model. We observed a significant increase in the CD69 surface marker on the B‐cell population in total spleen cells and on isolated B cells from BALB/c mice after in vitro rLi TXN1 stimulus. Activated B‐cells underwent further proliferation, as indicated by increased [ 3 H]thymidine incorporation. Cytokine quantification showed a dose‐dependent up‐regulation of interleukin (IL)‐10 secretion. B cells were identified as a source of this secretion. Furthermore, intraperitoneal injection of r Li TXN1 into BALB/c mice triggered the production of elevated levels of r Li TXN1‐specific antibodies, predominantly of the immunoglobulin M (IgM), IgG1 and IgG3 isotypes, with a minimum reactivity against other heterologous antigens. Taken together, our data suggest that r Li TXN1 may participate in immunopathological processes by targeting B‐cell effector functions, leading to IL‐10 secretion and production of specific antibodies.