Effect of Vitamin D3 on Antimicrobial Peptide Gene Expression in the Neutrophils of Pulmonary Tuberculosis Patients

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.