Li Xue-Chun, Su Xiao-Hong
Department of Sexually Transmitted Diseases, Research Institute of Dermatology, Peking Union Medical College, Chinese Academy of Medical Sciences, Nanjing, Jiangsu 210042, China .
Zhonghua Nan Ke Xue. 2018 May;24(5):452-456.
Neisseria gonorrhoeae (NG), as a pathogen of gonorrhea, is strictly limited to growth on the human host. In case of gonococcal infection, the body may recruit such inflammatory cells as neutrophils to resist the invasion of NG or initiate its adaptive immune response by antigen presentation to eliminate the pathogen. However, a series of immune escape mechanisms of NG make it difficult to clear up the infection. In the innate immune system, NG can not only secrete thermonuclease to degrade neutrophile granulocytes, inhibit respiratory burst to resist killing by neutrophils, activate NLRP3 to prompt the pyronecrosis of inflammatory cells, but also regulate the differentiation of macrophages to reduce the inflammatory response, combine with factor H to evade complement-mediated killing. NG infection can hardly give rise to effective adaptive immune response and immune memory, but can promote TGF-β production to inhibit Th1/Th2-mediated adaptive immune response, bind to CEACAM1 on the B cell surface to promote apoptosis in B cells, and combine with CEACAM1 on the T cell surface to inhibit helper T cell proliferation, which makes it difficult for B cells to produce high-affinity specific antibodies. With the increasing drug-resistance of NG, immunological studies may play a significant role in the development of novel therapies and effective vaccines against the infection.
淋病奈瑟菌(NG)作为淋病的病原体,严格局限于在人类宿主上生长。在淋病奈瑟菌感染的情况下,机体可能会募集嗜中性粒细胞等炎性细胞来抵抗NG的入侵,或者通过抗原呈递启动适应性免疫反应以清除病原体。然而,NG的一系列免疫逃逸机制使得感染难以清除。在固有免疫系统中,NG不仅可以分泌热核酸酶来降解嗜中性粒细胞,抑制呼吸爆发以抵抗嗜中性粒细胞的杀伤,激活NLRP3促使炎性细胞发生焦亡,还可以调节巨噬细胞的分化以减轻炎症反应,与因子H结合以逃避补体介导的杀伤。NG感染几乎不会引发有效的适应性免疫反应和免疫记忆,反而会促进转化生长因子-β的产生以抑制Th1/Th2介导的适应性免疫反应,与B细胞表面的癌胚抗原黏附分子1(CEACAM1)结合以促进B细胞凋亡,并与T细胞表面的CEACAM1结合以抑制辅助性T细胞增殖,这使得B细胞难以产生高亲和力的特异性抗体。随着NG耐药性的不断增加,免疫学研究可能在开发针对该感染的新型疗法和有效疫苗方面发挥重要作用。