小鼠肠上皮内淋巴细胞在粘膜免疫应答中的形态学研究

MORPHOLOGIC STUDIES ON INTESTINAL INTRAEPITHELIAL LYMPHOCYTES OF MICE IN MUCOSAL IMMUNE RESPONSE

采用免疫组织化学和电镜方法，观察了ＢＡＬＢ／ｃ小鼠灌服伤寒杆菌后回肠及集合淋巴小结圆顶区肠上皮内淋巴细胞（ｉｎｔｒａｅｐｉｔｈｅｌｉａｌｌｙｍｐｈｏｃｙｔｅ，ＩＥＬ）的形态和分布特征，以探讨ＩＥＬ在抗原诱导下的粘膜免疫应答中的作用。经免疫组织化学方法证实灌服伤寒杆菌后回肠及集合淋巴小结圆顶区肠上皮内含Ｂ和Ｔ两种淋巴细胞，以Ｂ淋巴细胞为主；电镜下可见上皮内淋巴细胞主要由小和中等淋巴细胞组成，且后者有两种形态。一种细胞器较少，与上皮微绒毛之间有紧密接触。另一种细胞器丰富，内质网呈扩张状态。同时观察到ＩＥＬ有的位于上皮细胞内，有的位于相邻的上皮细胞间隙内。本研究提示，小肠上皮不仅为粘膜免疫效应部位，而且也是免疫诱导部位。提示伤寒杆菌能诱导淋巴细胞向小肠上皮和圆顶区上皮迁移，且圆顶区上皮比小肠上皮更易接受抗原刺激。

The morphologic and distributive characterizations of intraepithelial lymphocyte (IEL) in ileum and the dome area of Peyer′s patch in BALB/c mice which took salmonella typhi were observed by electron microscopy and immunohistochemistry, in order to inquire about the role of IEL in the mucosal immune response under antigen inducement. By immunohistochemistry the results suggest that there are two types lymphocytes, T and B in IEL of ileum and the dome area, and B lymphocytes are more obvious. Under electron microscope, IEL constitutes small and moderate lymphocytes, and there are two types of morphology in the moderate lymphocytes in IEL. One type has fewer cell organelles, and there are tight contact among these cells and microvilli; the other has plentiful organelles and distended endoplasmic reticulum. Some IEL were observed in epithelium, and others in the intercellular space of epithelia. Therefore, intestinal epithelia is not only the effector site but inductive site of the mucosal immunity as well. These suggest that the bacteria may induce lymphocytes to migrate into the epithelia of intestine and dome area, and the epithelia of dome area tend to take antigen more easily than that of intestine.