Tamborrino Tiziana, Bonente Denise, Regoli Marì, Costa Valentina, Barone Virginia, Giacomello Emiliana, Collodel Giulia, Fagni Niccolò, Nicoletti Claudio, Bertelli Eugenio
Department of Molecular and Developmental Medicine, University of Siena, Via A. Moro, 2, 53100 Siena, Italy.
Department of Life Sciences, University of Siena, Via A. Moro, 2, 53100 Siena, Italy.
Int J Mol Sci. 2025 Mar 30;26(7):3207. doi: 10.3390/ijms26073207.
Follicle-associated epithelium (FAE) covering the lymphoid follicles of Peyer's patches (PPs) plays a central role in mucosal immunity. Here, we investigated FAE-derived intrafollicular epithelial bodies (IFEBs) that apparently detach from the FAE and sink deep into the lymphoid tissue of the PPs. Analysis of rabbit PP FAE was carried out by a variety of microscopy and immunohistochemistry techniques using a panel of specific antibodies to determine the nature of the IFEBs. IFEBs displayed the typical features of the FAE, with cytokeratin (CK)+ epithelial cells and CK+/vimentin+ M-cell-like cells. Serial sections of PP tissues showed that the IFEBs are formations frequently separated by the overlying FAE that maintains its integrity. Further, IFEBs showed the presence of junction-associated molecules like zonulin-1 and desmoplakins. Also, IFEBs apparently disaggregate within the lymphoid tissue, as demonstrated by basement membrane disappearance and the finding of isolated epithelial cells that acquire the features of non-polarized epithelial cells. Segments of the FAE in rabbit PPs can detach, forming IFEBs that migrate inside the lymphoid tissue. Although the biological relevance of the newly described IFEBs remains to be determined, we interpreted these data as showing the highly dynamic nature of the PP-associated FAE.
覆盖派尔集合淋巴结（PPs）淋巴滤泡的滤泡相关上皮（FAE）在黏膜免疫中起核心作用。在此，我们研究了源自FAE的滤泡内上皮小体（IFEBs），这些小体显然从FAE脱离并深入到PPs的淋巴组织中。利用一组特异性抗体，通过多种显微镜和免疫组织化学技术对兔PP FAE进行分析，以确定IFEBs的性质。IFEBs呈现出FAE的典型特征，有细胞角蛋白（CK）阳性上皮细胞和CK/波形蛋白双阳性的M细胞样细胞。PP组织的连续切片显示，IFEBs是经常被保持完整的上层FAE分隔开的结构。此外，IFEBs显示存在诸如闭合蛋白-1和桥粒斑蛋白等与连接相关的分子。而且，如基底膜消失以及发现获得非极化上皮细胞特征的孤立上皮细胞所表明的，IFEBs显然在淋巴组织内解体。兔PPs中FAE的片段可以脱离，形成在淋巴组织内迁移的IFEBs。尽管新描述的IFEBs的生物学意义仍有待确定，但我们将这些数据解读为表明与PP相关的FAE具有高度动态性。
