Distribution of Intraepithelial lymphocytes in the murine small intestine : The variability of the morphological property and function

形态分析显示不同绒毛部位的肠上皮内淋巴细胞(IEL)亚群不同(有颗粒等)。颗粒酶B(GRB)被证实参与了IEL激活引起的上皮细胞DNA断裂的诱导，这一结果提示了一种不同于先前报道的穿孔素(PFN)/GRB系统的新的DNA断裂诱导机制的可能性。我们还发现，位于肠道防御系统一线的IEL对刺激高度敏感，因此是一次性的，当受到刺激时，最终会导致周围绒毛上皮细胞的DNA断裂。

Different intestinal intraepithelial lymphocytes (IEL)subgroups (presence of granules, etc.)in different villus sites were demonstrated by morphological analysis. Granzyme B (GrB)has been proved to be involved in the induction of DNA fragmentation of epithelial cells due to IEL activation, the results suggest the possibility of a new DNA fragmentation induction mechanism different from that of previously reported perforin (Pfn)/GrB system. We also found that IELs in the front line of the intestinal defense system are highly stimulus-sensitive, thus are disposable, and, when stimulated, finally causing DNA fragmentation in the surrounding villus epithelial cells.