Current Science

K. Afsal ¹, V. V. Banurekha ², N. Meenakshi ³, M. Harishankar ¹, P. Selvaraj ¹

Affiliations
1 Department of Immunology, National Institute for Research in Tuberculosis (formerly Tuberculosis Research Centre), Indian Council of Medical Research, 1, Mayor Sathyamoorthy Road, Chetput, Chennai 600 031, IN
2 Department of Clinical Research, National Institute for Research in Tuberculosis (formerly Tuberculosis Research Centre), Indian Council of Medical Research, 1, Mayor Sathyamoorthy Road, Chetput, Chennai 600 031, IN
3 Institute for Thoracic Medicine, Chetput, Chennai 600 031, IN

Abstract

We studied the effect of 1α 25 dihydroxy vitamin D3 (1α,25(OH)₂D₃), the active form of vitamin D₃, on the expression of cathelicidin (CAMP), defensin-α3 (DEF- α3) and vitamin D receptor (VDR) genes in neutrophils cultured with or without Mycobacterium tuberculosis (Mtb) from pulmonary tuberculosis patients and healthy controls. Vitamin D₃ significantly enhanced the CAMP, DEF-α3 and VDR mRNA expression in the neutrophils of both the study groups (P < 0.05). Moreover, significantly upregulated CAMP expression was observed in vitamin D₃-treated neutrophils infected with Mtb (P < 0.05) in both the study groups. These findings suggest that vitamin D₃ enhances innate immunity by increasing the expression of the CAMP gene, which might inhibit the growth of Mtb at the site of infection.

Keywords

Antimicrobial Peptide Genes, Cathelicidin, Neutrophils, Tuberculosis, Vitamin D₃.

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M. Harishankar ¹, K. Afsal ¹, N. Meenakshi ², P. Selvaraj ¹

Affiliations
1 Department of Immunology, National Institute for Research in Tuberculosis (Formerly Tuberculosis Research Centre), Indian Council of Medical Research, 1, Mayor Sathyamoorthy Road, Chennai 600 031, IN
2 Institute for Thoracic Medicine, Chetput, Chennai 600 031, IN

Abstract

We studied the effect of 1,25-dihydroxy vitamin D3 [1,25(OH)₂D,₃] on toll-like receptor (TLR) gene expression in neutrophils cultured with Mycobacterium tuberculosis (Mtb) with or without 1,25(OH)₂D₃ in pulmonary tuberculosis patients and healthy controls. 1,25(OH)₂D₃ significantly increased the expression of TLR2, TLR9 and TIRAP genes compared to control cells in both the study groups (P < 0.05). In healthy controls, a significantly upregulated expression of TIRAP was observed in Mtb infected cells cultured with 1,25(OH)₂D₃ compared to Mtb infected cells alone (P < 0.05). In conclusion, 1,25(OH)₂D₃ upregulated the expression of TLR and TIRAP genes, which could lead to the activation of TLR signalling pathways and augment the innate immunity to tuberculosis.

Keywords

Gene Expression, Neutrophils, Tuberculosis, Toll-like Receptors.

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