自转运蛋白是革兰阴性菌中重要的毒力因子，参与细菌的粘附定植、侵袭、免疫逃逸、细胞毒性等致病过程。本课题组前期研究首次发现，淋病奈瑟菌FA1090菌株基因编码产物中存在一种新的丝氨酸蛋白酶自转运蛋白——NGO2105蛋白。进一步研究发现该蛋白在不同淋病奈瑟菌菌株间高度保守，且能诱导宿主产生杀菌性抗体，提示其可能是较有潜力的蛋白疫苗靶点。此外，用制备的NGO2105蛋白抗体能显著抑制淋病奈瑟菌对尿道上皮细胞的粘附能力，提示该蛋白可能在粘附过程中发挥重要作用。基于上述基础，我们认为深入探讨NGO2105蛋白的生物学功能及致病机制，对淋病奈瑟菌感染的防治具有重要意义。因此，本课题拟采用亚细胞定位分析、基因突变等技术，重点分析NGO2105蛋白的自转运特征及丝氨酸蛋白酶活性；通过NGO2105基因敲除和回复技术评价淋病奈瑟菌的粘附侵袭、补体沉积和小鼠感染定植能力，以揭示NGO2105蛋白的致病作用。

Autotransporter proteins constitute a large family of extracellular proteins that contribute to bacterial virulence, involved in bacterial adhesion colonization,invasion,immune escape, cytotoxicity and other processes. Our previous results found that NGO2105 protein is a new kind of serine protease transporter in Neisseria gonorrhoeae FA1090 strain. Bacteria liquid PCR showed that ngo2105 gene is highly conserved among different ST types of Neisseria gonorrhoeae.NGO2105 protein was successfully cloned and expressed in Escherichia coli in our previous research. Polyclonal antibody of NGO2105 protein was prepared. Further studies showed that polyclonal antiserum of NGO2105 showed higher bactericidal specificity compared with the control serum. These results suggested that it may be a promising target for protein vaccine. Antibody adhesion inhibition experiments showed that the polyclonal antiserum of NGO2105 could significantly inhibit the adhesion ability of neisseria gonorrhea on urinary epithelial cell. We propose that NGO2105 protein may participate in the adhesion process. But the function and pathogenic role of NGO2105 is unclear. To answer this question,we investigated the autotransporter features and serine protease activity of NGO2105 by use of subcellular localization analysis and gene mutation technology.Further,cell adhesion, complement deposition and mice infection experiment were determined to reveal the pathogenic roles of NGO2105 protein. This study may elucidate the biological function and pathogenic role of NGO2105 protein, and can help to better.understand the pathogenesis role of serine protease autotransporter in Neisseria gonorrhoeae.These works will paly a significance role in looking for new antibacterial and vaccine targets.