The innate immune response to tuberculosis infection may involve the increased production of nitric oxide and cathelicidin due to the up-regulated expression of the vitamin D receptor (VDR), though this proposed mechanism remains controversial. The aim of this study was to determine how the exposure of human monocytes to Mycobacterium tuberculosis
) DNA affects the production of nitric oxide and cathelicidin, as well as the expression of VDR.
This study was performed using monocytes obtained from healthy donors. After 24 h incubation, monocytes were stimulated with M. tuberculosis
DNA for 18 h to determine the expression of VDR mRNA and the production of nitric oxide and cathelicidin versus non-stimulated cells (the control group).
The expression of VDR mRNA was higher in the monocytes exposed to M. tuberculosis
DNA compared to the control group (P = 0.020). Monocytes exposed to M. tuberculosis
DNA also showed significantly increased production of nitric oxide and cathelicidin compared to the control group (P = 0.0001; P = 0.028).
The stimulation of human monocytes with M. tuberculosis
DNA increases the expression of the VDR mRNA and the production of nitric oxide and cathelicidin.