Molecular and functional morphological studies of M cells

我们已经研究了M细胞可以吸收广泛的大分子、微生物和颗粒，并将它们运输到粘膜淋巴样组织中的免疫能力细胞。研究表明，肠道相关淋巴组织（GALT）的M细胞在这种局部肠道免疫的启动中起着“第一信息通道”的作用。鼻咽扁桃体在抗原摄取引发粘膜免疫反应中的作用尚不清楚。本研究表明，鼻咽淋巴组织（NALT）的M细胞在超微结构和功能上与人类佩耶氏斑和结肠淋巴滤泡相似。这些发现表明NALT与GALT有相似之处，其抗原摄取能力可能对上气消化道免疫的启动很重要。目前，这些免疫抑制剂对Peyer's斑块结构的影响，以及它们是促进还是阻碍M细胞对抗原的摄取和运输，更多的是未知的。本项目研究了这些免疫抑制剂对Peycr贴片的影响，Peycr贴片通过肠道相关淋巴组织中肠道微生物和大分子的摄取和运输在粘膜免疫反应中起重要作用。研究表明，FK和Cs可能产生免疫抑制作用，至少部分是通过减少颗粒进入Peyer's斑块的摄取和运输，以及减少Peyer's斑块FAE中免疫反应细胞的数量。Vimentin在兔Peyer’s patches和阑尾的M细胞中特异性表达，但在其他胃肠道上皮细胞中不表达。然而，我们发现免疫电镜显示绒毛上皮中标记细胞的微绒毛比邻近的吸收细胞短，线粒体小而稀疏，这是杯状细胞的超微结构特征。在细胞核周围和杯状细胞的质膜下可以辨认出静脉蛋白丝。在家兔小肠中，波形蛋白可用于杯状细胞和M细胞的检测，并有助于对这些鲜为人知的细胞的研究。少

We have studied that M cells can take up a broad range of macromolecules, microorganisms, and particles and transport them to immunocompetent cells in underlying mucosal lymphoid tissues. It has been shown that the M cells of gut associated lymphoid tissue (GALT) have the role of first information conduit" in the initiation of this local intestinal immunity. "The role of the nasopharyngeal tonsils in antigen uptake for initiation of the mucosal immune response is unknown. This project showed that the M cells ofnasopharyngeal lymphoid tissue (NALT) were ultrastructurally and functionally similar to those in human Peyer's patches and colonic lymphoid follicles. These findings indicate that NALT bears similalities to the GALT, and its antigen uptake capacity may be important for initiation of immunity in the upper aerodigestive tract.At present, the effects of these immunosuppressants on Peyer's patch structure and whether they facilitate or retard M cell uptake and treansport of antigens … More are unknown. The present project examined the effects of these immunosuppressants on Peycr's patches, which play an important role in mucosal immune response through uptake and transport of enteric microorganisms and macromolecules in the gut-associated lymphoid tissues. It was shown that FK and Cs may produce immunosuppressive effects, at least in part, through reduction of the uptake and transport of particles into Peyer's patches, and by reduction of the number of immunoreactive cells in FAE of Peyer's patches.Vimentin has previously been shown to be expressed in rabbit M cells of Peyer's patches and appendixes specifically but not in other gastrointestinal epithelial cells. However, we found that immunoelectron microscopy revealed that the labeled cells in villus epithelium have shorter microvilli than do adjacent absorptive cells and small sparese mitochondria, which are ultrastructural characteristics of cup cells. Vimentin filaments were recognized in the area surrounding the nucleus and extending beneath the plasma membrane of cup cells. In rabbit small intestine, vimentin is useful for detection of cup cells as well as M cells and may facilitate investigation of these little understood cells. Less