Consistent with epithelial fucosylation, epithelial Fut2 expression was also higher in the ileum ( Fig. The frequency of F-ECs, detected with the α(1,2)-fucose–recognizing lectin Ulex europaeus agglutinin-1 (UEA-1), was low in the duodenum and jejunum (part 1 and a portion of part 2 <15% F-ECs) and gradually increased toward the ileum (part 4 40 to 90% F-ECs) ( Fig. To assess the inductive mechanism of intestinal epithelial fucosylation, we first investigated the localization of fucosylated ECs (F-ECs) along the length of the small intestine, divided equally into four parts from the duodenum (part 1) to the terminal ileum (part 4), in naïve mice ( Fig. Microbiota induces epithelial fucosylationĮpithelial fucosylation, a major glycosylation process, occurs in the small intestine ( 10, 11). Although a previous report proposed a model in which Bacteroides–EC interaction mediates epithelial fucosylation ( 7), the precise mechanisms by which Fut2 regulates fucosylation remain largely unknown. Therefore, epithelial fucose functions as a mediator between the host and commensal microbiota. Indeed, a lack of Fut2 alters the diversity and composition of the fecal microbiota in humans and mice ( 20, 21). Specific commensals, in particular Bacteroides, have been shown to induce epithelial fucosylation and are able to catabolize fucose for energy or incorporate it into bacterial cellular components-capsular polysaccharides-that give microbes a survival advantage in competitive environments ( 8, 9). Signals from commensal bacteria are required for epithelial fucosylation ( 6). The importance of epithelial fucose has been explored through studies of host–microbe interactions.
In addition, inactivating polymorphisms of FUT2 are associated with metabolic abnormalities and infectious and inflammatory diseases in humans ( 13– 19). Defective Fut2 has been shown to result in susceptibility to Candida albicans infection in mice ( 12).
#Shintaro sakamoto rar Patch#
Fut1 regulates fucosylation of Peyer’s patch (PP) M cells, whereas Fut2 is a key enzyme regulating intestinal columnar epithelial fucosylation and the production of secretory fucosylated ABO(H) histo-blood group antigens ( 11). Two fucosyltransferases, Fut1 and Fut2, mediate intestinal epithelial fucosylation, and each enzyme acts on a distinct subset of epithelial cells. Fucosylated glycans are generated by the addition of an L-fucose residue via an α1-2 linkage to the terminal β-D-galactose residues of glycan in a process catalyzed by fucosyltransferase. In particular, type 3 innate lymphoid cells (ILC3) produce interleukin-22 (IL-22), which not only regulates the homeostasis of the commensal microbiota but also protects against Citrobacter rodentium infection, presumably by inducing EC-derived antimicrobial molecules such as RegIIIγ ( 2– 5).įucosylated carbohydrate moieties expressed on intestinal ECs are involved in the creation of an environmental niche for commensal bacteria in mice and humans ( 6– 10). Resident commensal bacteria support the development of this functional mucosal immune system, and in turn, mucosal immune cells control the homeostasis of the gut microbiota and protect against pathogenic bacterial infection through intestinal ECs. ECs play key roles in initiating and maintaining an immunologically appropriate and balanced environment in reaction to constant foreign stimulation ( 1). Intestinal epithelial cells (ECs) are the first line of defense against foreign antigens, including those from commensal and pathogenic bacteria. The intestinal epithelium is a physical barrier that separates the environments inside and outside the mucosal surface. In the gastrointestinal tract, bilateral regulation between the gut microbiota and the host creates a mutually beneficial environment.
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