Studies on the colonization mechanism of indigenous bacteria in alimentary tract

本研究阐明了本地细菌在大鼠消化道的定植机制。本文的研究结果如下：1。原生细菌的基本定植位点是肠绒毛和Peyer's斑块中凋亡晚期的上皮细胞。滤泡相关上皮（FAE）中M细胞的分化与FAE和邻近粘膜上本地细菌的定植有关。普通柱状上皮细胞吞噬退化的细菌，而M细胞在Peyer's斑块FAE中吞噬完整的细菌。从超微结构上看，细菌的吞噬可能是由M细胞的膜受体介导的。凋亡晚期上皮细胞组织化学检测特异性糖表达，而M细胞无特异性糖表达。原生细菌的基本定植位点是整个消化道中凋亡晚期的上皮细胞。从这些部位，本地细菌扩散到粘膜深处。粘液淋巴滤泡的邻近FAE可监测这种增殖。在细菌附着位点，本地细菌通过上皮细胞骨架重排的物理防御和抗菌物质分泌的化学防御被消灭。透射电镜下对Peyer’s patches的FAE进行了详细的分化和再分化过程的分析。

This research clarified the colonization mechanisms of indigenous bacteria in rat alimentary tracts. The results obtained in this research are as follows:1. Fundamental colonization site of indigenous bacteria is the epithelial cells with late apoptotic stage in intestinal villi and Peyer's patches.2. Differentiation of M cells in the follicle-associated epithelium (FAE) is co-related with the colonization of indigenous bacteria on FAE and neighboring mucosa. The ordinary columnar epithelial cells engulf the degenerated bacteria, whereas M cells engulf the intact bacteria in FAE of Peyer's patches. This engulfment of bacteria might be mediated with membrane receptor in M cells form ultrastructural findings.3. Specific sugar expression was histochemically determined on the epithelial cells with late apoptotic stage, whereas M cells expressed no specific sugar.4. Fundamental colonization site of indigenous bacteria is the epithelial cells with late apoptotic stage in entire alimentary tract. From these sites, indigenous bacteria proliferate deeply into mucous membrane. This proliferation is monitored by neighboring FAE of mucous lymphatic follicles.5. At bacterial attachment sites, indigenous bacteria are eliminated by both the physical defense of rearrangement of epithelial cytoskeletons and the chemical defense of secretion of antibactericidal substances.6. The detailed differentiation and re differentiation processes were clarified in FAE of Peyer's patches under transmission electron microscope.