1, 25-dihydroxyvitamin D3 downregulates cytotoxic effector response in pulmonary tuberculosis. - GreenMedInfo Summary

1,25-dihydroxyvitaminD[1,25(OH)D] modulates both the innate and adaptive immunity in tuberculosis. We explored the effect of 1,25(OH)Don cytolytic molecules like perforin, granulysin, and granzyme-B in T-cells and natural killer cells during M. tuberculosis (Mtb) infection. Peripheral blood mononuclear cells (PBMCs) from 45 healthy controls (HCs) and 45 pulmonary tuberculosis (PTB) patients were cultured with Mtb in the absence or presence of 1,25(OH)Dfor 72 h. The percentage of perforin, granulysin, and granzyme-B positive cells were estimated by flow cytometry. 1,25(OH)Dsignificantly decreased the percentage of cytolytic molecules in total, CD4+, CD8+ and CD56+ cells in HCs and PTB patients (p < 0.05). Moreover, 1,25(OH)Ddownregulates IFN-γ levels while upregulate the anti-inflammatory cytokine IL-10. Correlation revealed that the total percentage of cytolytic molecules were positively correlated with IFN-γ level, whereas negatively correlated with IL-10 level in both the study subjects (p < 0.05). This results suggests that 1,25(OH)Ddownregulate the expression of cytolytic molecues and act as anti-inflammatory in adaptive immune response, which might help to reduce inflammation and tissue damage during the active stage of the disease.