CD8+ T Cells as a Source of IFN-γ Production in Human Cutaneous Leishmaniasis.

Autor: Rostami, Mahmoud Nateghi, Keshavarz, Hossein, Edalat, Rosita, Sarrafnejad, Abdolfattah, Shahrestani, Tahereh, Mahboudi, Fereidoun, Khamesipour, Ali
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Zdroj: PLoS Neglected Tropical Diseases; Oct2010, Vol. 4 Issue 10, p1-9, 9p, 2 Charts, 4 Graphs
Abstrakt: Background: In human leishmaniasis Th1/Th2 dichotomy similar to murine model is not clearly defined and surrogate marker(s) of protection is not yet known. In this study, Th1/Th2 cytokines (IL-5, IL-10, IL-13 and IFN-γ) profile induced by purified CD4+/CD8+ T cells in response to Leishmania antigens were assessed at transcript and protein levels in 14 volunteers with a history of self-healing cutaneous leishmaniasis (HCL) and compared with 18 healthy control volunteers. Methodology/Principal Findings: CD4+/CD8+/CD14+ cells were purified from peripheral blood using magnetic beads; CD4+/CD8+ T cells were co-cultured with autologous CD14+ monocytes in the presence of soluble Leishmania antigens (SLA). Stimulation of either CD4+ T cells or CD8+ T cells of HCL volunteers with SLA induced a significantly (P<0.05) higher IFN-γ production compared with the cells of controls. Upregulation of IFN-γ gene expression in CD4+ cells (P<0.001) and CD8+ cells (P = 0.006) of HCL volunteers was significantly more than that of controls. Significantly (P<0.05) higher foldexpression of IFN-γ gene was seen in CD4+ cells than in CD8+ cells. In HCL volunteers a significantly (P = 0.014) higher number of CD4+ cells were positive for intracellular IFN-γ production than CD8+ cells. Conclusions/Significance: Collectively, the volunteers have shown maintenance of specific long-term immune responses characterized by a strong reaction to leishmanin skin test and IFN-γ production. The dominant IFN-γ response was the result of expansion of both CD4+ and CD8+ T cells. The results suggested that immune response in protected individuals with a history of zoonotic cutaneous leishmaniasis (ZCL) due to L. major is mediated not only through the expansion of antigenspecific IFN-γ producing CD4+ Th1 cells, but also through IFN-γ producing CD8+ T cells. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index