The roles of apoptosis-induced villous columnar epithelial cells in intestinal immune response

本研究阐明了大鼠小肠上皮细胞凋亡与免疫球蛋白吸收的关系。本研究除了阐明肠道吸收抗原和特异性抗体的转运途径外，还揭示了食物抗原吸收与特异性抗体吸收之间的密切关系。本研究结果如下：1.大鼠小肠绒毛柱状上皮细胞凋亡可吸收Ig G、Ig A和Ig M。食物抗原刺激可诱导上皮细胞凋亡。凋亡的绒毛柱状上皮细胞基底质的碎裂导致吸收的免疫球蛋白分泌到组织中。在口服食物抗原致敏的大鼠中，口服的同一抗原与特异性抗体一起被凋亡的绒毛柱状上皮细胞吸收。Peyer‘s斑滤泡相关上皮细胞中的M细胞比凋亡的上皮细胞更能吸收抗原-抗体复合体。补丁。几乎所有的抗原都是通过淋巴管进入全身血液循环，而极少数的抗原是由门静脉吸收的。抗原和被吸收的特异性抗体都被肝细胞捕获，不会分泌到胆汁中。此外，本研究还发现：7.M细胞直接来源于肠隐窝未分化细胞，不会死亡。M细胞再分化为微绒毛上皮细胞，最终在卵泡相关上皮细胞中通过凋亡而死亡。细胞凋亡在大鼠骨髓中红细胞的成熟和去核过程中起重要作用。在大鼠骨髓中，红母细胞岛向血窦迁移，并将成熟的红系细胞输送到外周血中。

This research clarifies the relationship between the apoptotic epithelial cells and the absorption of immunoglobulins in rat small intestine. This research also shows the close relationship between the absorption of food antigens and the absorption of specific antibody, in addition to the clarification of transportation routes of both intestinally absorbed antigen and specific antibody. The results in this research are as follows :1. IgG, lgA and IgM are absorbed by apoptotic villous columnar epithelial cells in rat small intestine.2. The epithelial apoptosis is induced by food antigenic stimulation.3. The fragmentation of basal cytoplasm of apoptotic villous columnar epithelial cell results in the secretion of absorbed immunoglobulins into the tissues. In rats being sensitized by oral administration of food antigen, the orally administrated same antigen is absorbed with specific antibody by apoptotic villous columnar epithelial cells.4. The absorption of antigen-antibody complex is more actively done by apoptotic epithelial cells than M cells in follicle-associated epithelium of Peyer's patch.5. patch.6. Almost all of antigen is persorbed into systemic blood circulation by lymphatics, whereas a little antigen was done by portal vein. Both the antigen and absorbed specific antibody are trapped by hepatocytes and never secreted into bile.Additional findings in this research are as follows :7. M cells are directly originated from intestinal crypt undifferentiated cells and never die apoptosis. M cells redifferentiate into microvillous epithelial cells and finally die by apoptosis in follicle-associated epithelium.8. Apoptosis plays an important role in maturation and denucleation of erythroblasts in rat bone marrow.9. Erythroblastic islands migrate toward the sinusoids and transport the matured erythroid cells into peripheral blood in rat bone marrow.