The mucosae represent the first line of defense against the invasion of most pathogens, and the mucosal immune system plays a crucial role in the control of infection. Mucosal vaccination can trigger both humoral and cell-mediated immune responses mucosally as well as systemically. Hence, protective immune responses can be elicited effectively by mucosal vaccination. Microfold (M) cells being unique to the mucosal immune system can take up luminal antigens and initiating antigen-specific immune responses. The number of antigen uptake by M cells is directly related to the immune efficacy of mucosal vaccines. Utilizing M cell ligands, M cells-targeting antigen delivery can achieve highly effective mucosal immune responses. The strategy of targeted delivery of antigens to M cells and its applications can be used for the improvement of mucosal immune responses and the development of mucosal vaccines. Despite these efforts, successful development of safe and effective mucosal vaccines remains a big challenge and needs a long way to go, and provably still resort to further researches on cellular properties and functions as well as mucosal immune mechanisms.
黏膜是阻止病原入侵的第一道防线，黏膜免疫系统在抵抗感染方面起着至关重要的作用。通过黏膜途径接种疫苗可以同时诱导黏膜和全身免疫反应，因此，理论上针对黏膜的免疫策略是最合理和有效的。但黏膜免疫系统的复杂性和屏障作用造成抗原诱导的免疫应答水平低下，制约了黏膜疫苗的发展。M 细胞 (Microfold cells)是黏膜免疫系统所独有的，其具有捕获腔内抗原和启动抗原特异性免疫应答的功能。M 细胞摄取抗原的多少直接关系到黏膜疫苗的免疫效力，而利用M 细胞配体可将抗原靶向递呈给M 细胞，从而实现高效的黏膜免疫应答。靶向M 细胞的抗原递送策略及其应用可以提高黏膜免疫应答水平，促进黏膜疫苗的研制。尽管如此，要成功研制安全高效的黏膜疫苗，今后依然有漫长的路要走，这可能有赖于进一步探究M 细胞的特性和功能及黏膜免疫机制。.
Keywords: microfold cells; mucosal immunity; mucosal vaccines; targeted antigen delivery.