Section of Anatomy and Pathology, Institute of Basic Sciences and Aquatic Medicine, Norwegian School of Veterinary Science, Ullevålsveien 72, Oslo, Norway.
Dev Comp Immunol. 2010 Jul;34(7):768-74. doi: 10.1016/j.dci.2010.02.007. Epub 2010 Mar 1.
Antigen uptake has been shown to occur in the teleost intestine, but so far, limited information is available on the distribution and nature of cells involved in the process, and M cells, known for their antigen-sampling abilities in mammals, have not been identified. Here, different intestinal segments from salmonid fish were exposed to gold-BSA to identify antigen-sampling cells. Sections from exposed intestine were examined by light and electron microscopy. Uptake of gold-BSA was restricted to very few dendritic-like cells and to a limited number of epithelial cells located in the mucosal folds in the second segment of the mid-intestine. Gold-positive epithelial cells displayed diverging and electron-dense microvilli with channels intruding into the cytoplasm. A lectin binding experiment demonstrated the presence of cells with mammalian M-cell characteristics in the identical regions. As the identified epithelial cells shared some morphological similarities with immature mammalian M cells, this phenotype may represent evolutionary early antigen-sampling enterocytes.
已证实抗原摄取发生在硬骨鱼的肠道中，但到目前为止，关于参与该过程的细胞的分布和性质的信息有限，并且尚未鉴定出已知具有抗原采样能力的哺乳动物中的 M 细胞。在这里，用金-BSA 处理来自鲑鱼科鱼类的不同肠段以鉴定抗原采样细胞。用光镜和电子显微镜检查暴露于肠段的切片。金-BSA 的摄取仅限于少数几个树突状样细胞和位于中肠第二段黏膜褶皱中的有限数量的上皮细胞。金阳性的上皮细胞显示出发散的和电子致密的微绒毛，其通道侵入细胞质。凝集素结合实验证明在相同区域存在具有哺乳动物 M 细胞特征的细胞。由于鉴定出的上皮细胞与未成熟的哺乳动物 M 细胞具有某些形态相似性，因此这种表型可能代表进化早期的抗原采样肠细胞。
