Abstract:

Objective To investigate the mechanism of interleukin（IL）⁃6/signal transducer and activator of transcription 3（STAT3）pathway in macrophage immunity of patients with pulmonary tuberculosis. Methods A total of 92 cases of pulmonary tuberculosis patients（observation group）treated in Wuhan Jinyintan Hospital from October 2017 to October 2019 were recruited as the research objects，and 95 healthy persons（control group） were selected as the control group. Fasting peripheral venous blood was collected. The protein expression levels of STAT3，p⁃STAT3，Nuclear factor⁃κB（NF⁃κB）p65 and p⁃NF⁃κB p65 were detected by Western blot. The levels of serum inflammatory factors IL⁃6，IL⁃10 and tumor necrosis factor⁃α（TNF⁃α）were detected by enzyme⁃linked immunosorbent assay（ELISA）. Macrophages were cultured in vitro and divided into normal group（without treat⁃ ment）and infection group（infected with Mycobacterium tuberculosis）. Western blot was used to detect the protein expression levels of STAT3，p⁃STAT3，NF⁃κB p65 and p⁃NF⁃κB p65 in macrophages，and the levels of IL⁃6，IL⁃10 and TNF⁃α in macrophage supernatant were detected by ELISA. Results Compared with those in the control group， the protein levels of p⁃STAT3/STAT3，p⁃NF⁃κB p65/NF⁃κB p65 in the peripheral blood，and the expression levels of IL⁃6，IL⁃10 and TNF⁃α in serum in the observation group were significantly higher than those in the control group （P < 0.05）. Compared with those in the normal group，the protein levels of p⁃STAT3/STAT3，p⁃NF⁃κB p65/NF⁃κB p65 in macrophages，and the expression levels of IL⁃6，IL⁃10 and TNF⁃α in supernatant of macrophage in infected group were significantly higher than those in normal group（P < 0.05）. Conclusion IL⁃6/STAT3 pathway is activated in pulmonary tuberculosis patients and macrophages infected with Mycobacterium tuberculosis. Macrophages may play an immunomodulatory role in pulmonary tuberculosis by activating IL⁃6/STAT3 pathway.

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