Role of chemokine CCL20 and its receptor CCR6 against bacterial infection.

本研究旨在探讨趋化因子CCL20-CCR6系统在沙门氏菌和其他微生物感染小鼠肠道和淋巴器官中的作用。本研究采用非免疫小鼠和经口免疫鼠伤寒沙门氏菌弱毒株的小鼠，分别分析了鼠伤寒沙门氏菌强毒株攻击后的初次免疫应答和二次免疫应答。在18种小鼠趋化因子受体中，29.2L17是针对CCR6的单抗，能够染色已知表达CCR6的正常小鼠淋巴样细胞。此外，29.2L17可用于免疫组织化学染色小鼠组织中表达CCR6的细胞。但29.2L17对小鼠CCR6没有明显的中和活性。我们建立了口服免疫和口服攻击鼠伤寒沙门氏菌的实验条件。在此条件下，在鼠伤寒沙门氏菌攻击前或攻击后的不同时间点，分别从对照组和免疫组小鼠的肠道、肝脏和脾组织中采集标本。这些组织有助于分析CCL20-CCR6系统在粘膜免疫中的初级和二级免疫反应中的作用。我们还在体外和体内证明了角膜上皮细胞和基质角质细胞产生CCL20的能力。通过建立单纯疱疹间质角膜炎的小鼠模型，发现不仅上皮细胞而且基质角质细胞在角膜中有效地产生CCL20，并将表达CCR6的细胞如树突状细胞募集到炎症的角膜中。

This research is to investigate the role of the chemokine CCL20-CCR6 system at intestine and lymphoid organ in mice infected with Salmonella and other microorganisms We used non-immune mice and mice immunized perorally with avirulent strain of Salmonella typhimurium for the analysis of primary immune response and secondary immune response, respectively, after challenge with the virulent strain of Salmonella typhimurium.Using immunized Armenian hamster spleen cells, we established anti-mouse CCR6 monoclonal antibody termed 29.2L17. The monoclonal antibody 29.2L17 was specific for CCR6 among the 18 mouse chemokine receptors and capable of staining normal mouse lymphoid cells known to expree CCR6. Furthermore, 29.2L17 could be used for staining cells expressing CCR6 in mouse tissues by immunohistochemistry. However, 29.2L17 does not have a significant neutralizing activity against mouse CCR6.We established experimental conditions for peroral immunization and peroral challenge of Salmonella typhimurium. Using these conditions, intestinal tract, liver and spleen were collected from control or immunized mice before or after the challenge with Salmonella typhimurium at several time points. These tissues are useful for the analysis of the role of the CCL20-CCR6 system in primary and secondary immune responses in the mucosal immunity.We have also demonstrated the ability of corneal epithelial cells and stromal keratocytes to produce CCL20 in vitro and in vivo. By using a mouse model of herpetic stromal keratatis, it has been revealed that not only epithelial cells but also stromal keratocytes efficiently produce CCL20 in the cornea and recruit cells expressing CCR6 such as dendritic sells into inflamed cornea.