Identification of regulatory T cells during experimental Leishmania infantum infection

阅读量：

作者：

Olivia Roos Rodrigues a，Cláudia Marques a，Marta Soares-Clemente a，Maria Helena Ferronha b，Gabriela Maria Santos-Gomes a

展开

摘要：

Leishmania infantum is the causative agent of zoonotic visceral leishmaniasis (ZVL), a disease frequently characterized by specific impairment of cell-mediated immune responses and uncontrolled parasitization. Regulatory T cells (Treg) have been shown to be involved in the direct induction of immunosuppression of effector immune response during chronic Leishmania infections. The present study aims to investigate the possible involvement of Treg cells during L. infantum infection. Results indicate that CD4 + CD25 + regulatory T cells are present in L. infantum -infected BALB/c mice and exhibit phenotypic and functional characteristics of Treg. The presence of high levels of Foxp 3 gene expression and surface expression of α E β 7 integrin (CD103) suggest a predisposition for Treg retention within sites of L. infantum infection, as is the case of the spleen and draining lymph nodes, consequently influencing local immune response. Th1 and Th2 effector immune responses seem inadequate, due to Treg expansion. Foxp 3 expressing CD4 + CD25 + T cells are capable of producing TGF- β and may contribute to immunosuppression and better control of parasite-mediated-immunopathology during infection. Surprisingly, IL-10 producing-CD4 + CD25 Foxp 3 T cells were also identified as an additional source of IL-10 and may represent a type 1 regulatory T (Tr1) cell subset that is being induced by L. infantum parasites. These findings suggest that distinct regulatory T cells develop in response to L. infantum and may play a possible role in promoting parasite persistence and the establishment of chronic infection.

展开

关键词：

Ag crude Leishmania antigen crude Leishmania antigen APC antigen-presenting cell(s antigen-presenting cell(s CD cluster of differentiation cluster of differentiation Foxp3 forkhead box P3 forkhead box P3 GITR glucocorticoid-induced tumor-necrosis factor receptor family-related gene glucocorticoid-induced tumor-necrosis factor receptor family-related gene