BackgroundIn 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 FindingsCD4+/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 fold-expression 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/SignificanceCollectively, 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 antigen-specific IFN-γ producing CD4+ Th1 cells, but also through IFN-γ producing CD8+ T cells.

Little is known about the immunobiology of interleukin-17 (IL-17)-producing T cells and regulatory T cells (Treg) in chronic lymphocytic leukemia (CLL). In this study, the frequencies of Th17, Tc17, and CD39(+) Treg cells were enumerated in peripheral T cells isolated from 40 CLL patients and 15 normal subjects by flow cytometry. Our results showed a lower frequency of Th17 and Tc17 cells in progressive (0.99 ± 0.12 % of total CD3(+)CD4(+) cells; 0.44 ± 0.09 % of total CD8(+) cells) compared to indolent patients (1.57 ± 0.24 %, p = 0.042; 0.82 ± 0.2 %, p = 0.09) and normal subjects (1.78 ± 0.2 %, p = 0.003; 0.71 ± 0.09 %, p = 0.04). Decrease in IL-17-producing T cells was associated with CD39(+) Treg cells expansion. Variation of IL-17-producing cells and Treg cells in indolent and progressive patients was neither associated to the expression levels of Th1- and Th2-specific transcription factors T-bet and GATA-3 nor to the frequencies of IFN-γ and IL-4-producing CD4(+) T cells in a selected number of samples. Additionally, suppressive potential of CD4(+) Treg was similar in CLL patients and normal subjects. Our data indicate that progression of CLL is associated with downregulation of IL-17-producing T cells and expansion of Treg cells, implying contribution of these subsets of T cells in the progression of CLL.

Background: Despite beneficial effects of conjugated linoleic acids (CLAs) in animal studies, there is little information on their effects on human inflammatory and autoimmune diseases.

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A combination of Leishmania-reactive IFN-γ producing CD4(+)CD45RO(+)CD45RA(-)CCR7(-) T(EM) and Leishmania-reactive IL-2 producing CD4(+)CD45RO(+)CD45RA(-)CCR7(+) T(CM) are identified in individuals with history of CL which might play a role in protective recall immune response against Leishmania infection.