An inhibitory immunoreceptor Allergin-1 regulates the intestinal dysbiosis and barrier function in mice.

The article focuses on the role of Allergin-1, an inhibitory immunoglobulin-like receptor expressed on innate immune cells, in maintaining intestinal barrier integrity by regulating gut microbiota composition. Using Allergin-1-deficient (Milr1−/−) mice, the study demonstrates that absence of Allergin-1 leads to increased intestinal permeability, exacerbated dextran sulfate sodium (DSS)-induced colitis, and intestinal dysbiosis characterized by expansion of ampicillin-resistant Bifidobacterium pseudolongum. The findings indicate that B. pseudolongum contributes to barrier dysfunction in collaboration with other microbiota sensitive to neomycin, and that Allergin-1 likely modulates this process by inhibiting Toll-like receptor (TLR)-mediated inflammatory signaling in intestinal immune cells. This research highlights Allergin-1's importance in regulating immune-microbiota interactions critical for intestinal homeostasis.