Regulatory role of Cdx-2 and Taq I polymorphism of vitamin D receptor gene on chemokine expression in pulmonary tuberculosis.

Vitamin D receptor (VDR) gene variants have been shown to be regulating the immune response in tuberculosis. We studied the regulatory role of VDR promoter Cdx-2 and 3'UTR TaqI gene variants on chemokine levels from culture filtrate antigen (CFA) stimulated with or without 1,25(OH)2D3 treated peripheral blood mononuclear cells of 50 pulmonary tuberculosis patients (PTB) and 51 normal healthy controls (HCs). In CFA with 1,25(OH)2D3 treated cultures, the MIP-1α, MIP-1β, RANTES levels were significantly decreased in Cdx-2 AA genotype compared to GG genotype, while a significantly increased MIG level was observed in Cdx-2 AA genotype (p<0.05). In TaqI polymorphism, tt genotype significantly decreased MIP-1β and RANTES levels compared to TT genotype. Moreover, a significantly increased level of IP-10 and MIG was observed in TaqI tt genotype compared with TT genotype (p<0.05). The results suggests that the 1,25(OH)2D3 may alter the chemokine response through the VDR polymorphic variants during infection.