부산대학교 도서관

The lacuna in the knowledge of immunobiology, especially in visceral infections that are fatal if left untreated, are a major hurdle in getting a vaccine candidate for leishmaniasis. Till date, only a few drugs are available to combat human leishmaniasis and a vaccine candidate either prophylactic or preventive is still awaited. Therefore, identification of host and parasitic factors involved in the regulation of specific immune mechanisms are essentially needed. In this study, we observed that CD200-CD200R immune inhibitory axis regulates host macrophages effectors properties and helps antigen experienced T cells (CD4+CD44+ T cells) to acquire anti-inflammatory cytokines (IL-4, IL-10, TGF-β, IL-27) producing abilities in an NFkB independent manner. After CD200 blocking the macrophages effectively inhibited proliferation of Leishmania amastigotes and also induced the production of IL-12, IFN-γ, TNF-α and nitric oxide (NOx). Further, the blocking of CD200 signaling also restored macrophages MHC-II expression and helped CD4+CD44+ T cells to produce pro-inflammatory cytokines like IL-2, IL-12 and IFN-γ. The finding of this study suggested the importance of immune inhibitory mechanisms in controlling Leishmania growth and survival and therefore, requires more studies to understand its role in vaccine induced immunity. • CD200-CD200R role was investigated on macrophages and antigen experienced T cells function in L. donovani infection. • CD200-CD200R helps CD4+CD44+ T cells to produce IL-4, IL-10, TGF-β, IL-27 and dampen macrophages effector functions. • CD200 blocking restored macrophages normal functions and helped CD4+CD44+ T cells to produce IL-2, IL-12 and IFN-γ. • CD200 blocking also restricted the growth of parasites inside macrophages through increased NOx production. • Findings suggest that this axis can effectively control L. donovani survival and proliferation in infected host. [ABSTRACT FROM AUTHOR]