结核分枝杆菌Rv0927c蛋白抑制炎症应答的分子机制

结核分枝杆菌为重要的人兽共患病原菌，其产生抑炎效应在内的多种免疫逃逸策略，从而引起潜伏感染或疾病发生，前期研究显示结核分枝杆菌Rv0927c蛋白可以抑制宿主炎症应答，但是其分子机制还不清楚。本研究通过原核表达Rv0927c重组蛋白，并构建牛分枝杆菌BCG Rv0927c基因缺失株及表达Rv0927c的重组耻垢分枝杆菌作为研究材料。通过体外、体内试验，分别从蛋白水平和转录水平探讨Rv0927c蛋白对于宿主炎症应答的抑制效应及其规律，以此为切入点，应用Rv0927c序列全覆盖重叠多肽，探究其发挥抑炎效应的功能区域。随后，进一步分析Rv0927c蛋白发挥抑炎效应过程中所依赖的信号通路，以及重要信号分子的调控作用，并运用Co-IP技术筛选验证Rv0927c蛋白发挥抑炎效应的互作蛋白。通过对结核分枝杆菌Rv0927c蛋白的抑炎效应及其分子机制研究，将为进一步阐明结核分枝杆菌的免疫逃逸机制提供新认识。

Mycobacterium tuberculosis have evolved several mechanisms to escape host immune defense system, such as anti-inflammatory effect, and thus survive within the hostile environment, then it leads to latent infection or disease. Previous study showed that Mycobacterium tuberculosis Rv0927c protein can downregulate induction of some proinflammatory cytokines, however, the molecular mechanisms are not fully understood. In this study, recombinant Rv0927c protein will be prokaryotic expressed, Mycobacterium bovis BCG △Rv0927c strain and recombinant Mycobacterium smegmatis overexpressing Rv0927c will be constructed as research materials. The inhibitory effect of Rv0927c protein on the inflammation of host cells will be investigated by the Luminex liquichip and qRT-PCR technology in vitro and in vivo, respectively. And a series of overlapping peptides encompassing the entire Rv0927c sequence will be used to investigate the functional domain of Rv0927c protein. Subsequently, the dependent signaling pathways of anti-inflammatory effect and regulated function of some signal molecule will be analyzed. Finally, the interacting protein of Rv0927c protein will be screened and verified by Co-Immunoprecipitation and GST pull-down technology. To clarify the anti-inflammatory effect and molecular mechanism of Mycobacterium tuberculosis Rv0927c protein on the host cells, which will provide new ideas for the further elucidation of immune escape mechanisms of Mycobacterium tuberculosis.