Immune responses are elicited through antigen presentation and recognition by macrophages and T-l... more Immune responses are elicited through antigen presentation and recognition by macrophages and T-lymphocytes, respectively. The immunomodulatory effect of vitamin D3 on macrophage phagocytic potential with live Mycobacterium tuberculosis, spontaneous and M. tuberculosis culture filtrate antigen induced lymphocyte responses were studied in pulmonary tuberculosis patients (PTBPs) (n = 31) and normal healthy subjects (NHSs) (n = 43). Vitamin D3 at a concentration of 10−7 M significantly enhanced the macrophage phagocytosis of live M. tuberculosis in normal subjects with low phagocytic potential (less than 10%) (p = 0.015). No such increase was observed in PTBPs. Vitamin D3 significantly decreased the spontaneous lymphoproliferative response (p = 0.022) and increased the apoptosis of peripheral blood mononuclear cells in PTBPs (p = 0.024). In normals, vitamin D3 increased the spontaneous lymphoproliferative response. An inverse correlation between macrophage phagocytosis and spontaneous response was observed in NHSs, whereas a direct correlation was seen between vitamin D3-treated cells in normal subjects under in vitro condition. Vitamin D3 decreased the M. tuberculosis culture filtrate antigen induced lymphocyte response significantly in normal subjects (p = 0.0003), while it had no influence on the lymphocyte response in PTBPs. The present study suggests that exposure to vitamin D3 increases the phagocytic potential and spontaneous lymphoproliferative response but brings down the antigen-induced response in normals. In tuberculosis, addition of vitamin D3 has no significant effect on antigen-induced lymphoproliferative response. This may be due to the unresponsive nature of the cells to the action of vitamin D3 by virtue of the disease, which renders them inactive.
The regulatory role of vitamin D receptor (VDR) gene variants of BsmI, ApaI, TaqI, and FokI polym... more The regulatory role of vitamin D receptor (VDR) gene variants of BsmI, ApaI, TaqI, and FokI polymorphisms on vitamin D3-modulated macrophage phagocytosis with live Mycobacterium tuberculosis and lymphoproliferative response to M. tuberculosis culture filtrate antigen (CFA) was studied in patients with pulmonary tuberculosis (n = 46) and in normal healthy subjects (NHS) (n = 64). Vitamin D3 at a concentration of 1 × 10−7 M enhanced the phagocytic potential of normal subjects who had a phagocytic index of less than 20%. This increase was seen in subjects with the genotypes BB (p = 0.017), AA (p = 0.016), tt (p = 0.034), and FF (p = 0.013) and the extended genotype BBAAtt (p = 0.034). Normal subjects with BBAAtt performed better phagocytosis than individuals with bbaaTT genotype (p = 0.034). Vitamin D3 at 10−9, 10−8, and 10−7 M concentrations suppressed the lymphoproliferative response to CFA antigen in normal subjects. This decreased lymphocyte response was observed in normal individuals with the genotypes BB (p = 0.0009), tt (p = 0.016), and FF (p = 0.008) and the extended genotype BBAAtt (p = 0.02). Addition of vitamin D3 had no significant effect on macrophage phagocytosis and lymphoproliferative response to CFA in pulmonary TB patients. This may be due to the unresponsive nature of the cells to the action of vitamin D3 or the downregulated VDR expression by virtue of the disease, which renders them inactive. The genotypes BB, tt, and the extended genotype BBAAtt may be associated with increased expression of VDR which in turn regulate the action of vitamin D3 and modulate the immune functions to M. tuberculosis in NHS.
... Vitamin D receptor gene variants of BsmI, ApaI, TaqI, and FokI polymorphisms in spinal tuberc... more ... Vitamin D receptor gene variants of BsmI, ApaI, TaqI, and FokI polymorphisms in spinal tuberculosis. P Selvaraj,; SM Kurian,; G Chandra,; AM Reetha,; N Charles,; PR Narayanan. Article first published online: 10 DEC 2003. ... 6 Selvaraj P, Narayanan PR, Reetha AM. ...
Immune responses are elicited through antigen presentation and recognition by macrophages and T-l... more Immune responses are elicited through antigen presentation and recognition by macrophages and T-lymphocytes, respectively. The immunomodulatory effect of vitamin D3 on macrophage phagocytic potential with live Mycobacterium tuberculosis, spontaneous and M. tuberculosis culture filtrate antigen induced lymphocyte responses were studied in pulmonary tuberculosis patients (PTBPs) (n = 31) and normal healthy subjects (NHSs) (n = 43). Vitamin D3 at a concentration of 10−7 M significantly enhanced the macrophage phagocytosis of live M. tuberculosis in normal subjects with low phagocytic potential (less than 10%) (p = 0.015). No such increase was observed in PTBPs. Vitamin D3 significantly decreased the spontaneous lymphoproliferative response (p = 0.022) and increased the apoptosis of peripheral blood mononuclear cells in PTBPs (p = 0.024). In normals, vitamin D3 increased the spontaneous lymphoproliferative response. An inverse correlation between macrophage phagocytosis and spontaneous response was observed in NHSs, whereas a direct correlation was seen between vitamin D3-treated cells in normal subjects under in vitro condition. Vitamin D3 decreased the M. tuberculosis culture filtrate antigen induced lymphocyte response significantly in normal subjects (p = 0.0003), while it had no influence on the lymphocyte response in PTBPs. The present study suggests that exposure to vitamin D3 increases the phagocytic potential and spontaneous lymphoproliferative response but brings down the antigen-induced response in normals. In tuberculosis, addition of vitamin D3 has no significant effect on antigen-induced lymphoproliferative response. This may be due to the unresponsive nature of the cells to the action of vitamin D3 by virtue of the disease, which renders them inactive.
The regulatory role of vitamin D receptor (VDR) gene variants of BsmI, ApaI, TaqI, and FokI polym... more The regulatory role of vitamin D receptor (VDR) gene variants of BsmI, ApaI, TaqI, and FokI polymorphisms on vitamin D3-modulated macrophage phagocytosis with live Mycobacterium tuberculosis and lymphoproliferative response to M. tuberculosis culture filtrate antigen (CFA) was studied in patients with pulmonary tuberculosis (n = 46) and in normal healthy subjects (NHS) (n = 64). Vitamin D3 at a concentration of 1 × 10−7 M enhanced the phagocytic potential of normal subjects who had a phagocytic index of less than 20%. This increase was seen in subjects with the genotypes BB (p = 0.017), AA (p = 0.016), tt (p = 0.034), and FF (p = 0.013) and the extended genotype BBAAtt (p = 0.034). Normal subjects with BBAAtt performed better phagocytosis than individuals with bbaaTT genotype (p = 0.034). Vitamin D3 at 10−9, 10−8, and 10−7 M concentrations suppressed the lymphoproliferative response to CFA antigen in normal subjects. This decreased lymphocyte response was observed in normal individuals with the genotypes BB (p = 0.0009), tt (p = 0.016), and FF (p = 0.008) and the extended genotype BBAAtt (p = 0.02). Addition of vitamin D3 had no significant effect on macrophage phagocytosis and lymphoproliferative response to CFA in pulmonary TB patients. This may be due to the unresponsive nature of the cells to the action of vitamin D3 or the downregulated VDR expression by virtue of the disease, which renders them inactive. The genotypes BB, tt, and the extended genotype BBAAtt may be associated with increased expression of VDR which in turn regulate the action of vitamin D3 and modulate the immune functions to M. tuberculosis in NHS.
... Vitamin D receptor gene variants of BsmI, ApaI, TaqI, and FokI polymorphisms in spinal tuberc... more ... Vitamin D receptor gene variants of BsmI, ApaI, TaqI, and FokI polymorphisms in spinal tuberculosis. P Selvaraj,; SM Kurian,; G Chandra,; AM Reetha,; N Charles,; PR Narayanan. Article first published online: 10 DEC 2003. ... 6 Selvaraj P, Narayanan PR, Reetha AM. ...
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