The Roles of Peyer's Patches and Microfold Cells in the Gut Immune System: Relevance to Autoimmune Diseases

Abstract

Microfold (M) cells are located in the epithelium covering mucosa-associated lymphoid tissues, such as the Peyer's patches (PPs) of the small intestine. M cells actively transport luminal antigens to the underlying lymphoid follicles to initiate an immune response. The molecular machinery of M-cell differentiation and function has been vigorously investigated over the last decade. Studies have shed light on the role of M cells in the mucosal immune system and have revealed that antigen uptake by M cells contributes to not only mucosal but also systemic immune responses. However, M-cell studies usually focus on infectious diseases; the contribution of M cells to autoimmune diseases has remained largely unexplored. Accumulating evidence suggests that dysbiosis of the intestinal microbiota is implicated in multiple systemic diseases, including autoimmune diseases. This implies that the uptake of microorganisms by M cells in PPs may play a role in the pathogenesis of autoimmune diseases. We provide an outline of the current understanding of M-cell biology and subsequently discuss the potential contribution of M cells and PPs to the induction of systemic autoimmunity, beyond the mucosal immune response.

General Histological Characteristics of Lymphoid Nodules of Peyer’s Patches of the Small Intestine in Albino Rats After Administration of a Broad-Spectrum Antibiotic

“…At the same time, the issues related to the morphofunctional states of the most representative formations of the immune system of the intestinal mucous membranes, which are Peyer's patches, are underestimated, which, consequently, prompted the present experimental study, involving albino rats. The findings of morphometric analysis showed that after administration of a broad-spectrum antibiotic, Peyer's patches of the small intestine of albino rats remained unchanged both topographically and in their total amount, which contradicts the findings of some authors [8]. But at the same time, their total area is more than doubled, which, according to our data, becomes possible due to the appearance of a new generation of lymphoid nodules in them, the study of which was the aim of the present research.…”

The search for the Holy Grail: autoantigenic targets in primary sclerosing cholangitis associated with disease phenotype and neoplasia

“…Active inflammation in CD has been shown in intestinal PP which are even regarded as potential sites of the inflammatory onset [118][119][120]. There is growing evidence that intestinal dysbiosis in connection with an impaired intestinal immune response has a relevance to the development of autoimmune disorders [115]. In line with this assumption, an elevated risk for the onset of CD after gastrointestinal infections has been reported [121].…”

“…Thus, the discovery of GP2 as microbiome-sensing receptor for particularly FimH-positive bacteria on microfold (M) cells of the intestinal follicle-associated epithelium (FAE) fundamentally changed the understanding of GP2's physiological role [113,114]. Peyer's patches (PP) harbouring M cells and located in the epithelium covering MALT of the small intestine play a pivotal role in intestinal immune responses [115]. Along with the Ets transcription factor Spi-B, GP2 is a specific marker of mature M cells characterized by high up-take activity of luminal components [116,117].…”

Possible effects of titanium dioxide particles on human liver, intestinal tissue, spleen and kidney after oral exposure

“…The gut epithelium is composed of enterocytes, and mucus secreting cells (Goblet cells). The ileum and jejunum regions contain Peyer's patches, a gut associated lymphoid tissue where M-cells are located responsible for the uptake of particles (Frey et al 2019, Kobayashi et al 2019. NPs are usually believed to be taken up by Goblet cells and M-cells (Brun et al 2014), although this process is dependent on the particle size (Powell et al 2010).…”