Abstract: Objective  To study whether Mtb antigens have effect on the NLRP12 expression in peripheral blood monocytes, and provide experimental data to investigate the role of NLRP12 in tuberculosis.  Methods  Peripheral blood were collected from 15 healthy controls and 15 patients with active pulmonary tuberculosis. Monocytes were isolated from peripheral blood and then stimulated with Mtb antigens, including whole cell lysate of H37Rv strain and ESAT-6/CFP-10 peptide pool. Total RNA was extracted from unstimulated and stimulated cells, NLRP12 mRNA was detected by fluorescence quantitative PCR, and the difference of NLRP12 mRNA expression between stimulated and unstimulated cells was analyzed by paired t test.P value less than 0.05 was considered statistically significant.  Results The reduction of NLRP12 mRNA in monocytes from active pulmonary TB was significant following stimulation by whole cell lysate and peptide pool, which reduced to (1.09±0.78)×10^-2 (t=3.826, P<0.01) and (1.14±0.87)×10^-2 (t=3.695, P<0.01) from (1.8±1.26)×10^-2, respectively. The expression of NLRP12 mRNA in monocytes from healthy subjects was no significant change following stimulation by whole cell lysate and peptide pool, although which reduced to (1.2±0.87)×10^-2 (t=1.909, P>0.05) and (1.38±1.02)×10^-2 (t=1.151, P>0.05) from (1.65±0.99)×10^-2, respectively.  Conclusion  Mtb antigens can inhibit the NLRP12 expression in monocytes from patients with active pulmonary Tin vitro.

Key words: Tuberculosis, pulmonary, Mycobacterium tuberculosis, Intracellular signaling peptides and proteins, Monocytes, Recombinant fusion proteins