Epithelial-microbial crosstalk in polymeric Ig receptor deficient mice

Area of Science:

• Immunology
• Microbiology
• Gastroenterology

Background:

• Innate and adaptive immunity maintain gut homeostasis with the microbiota.
• Polymeric Ig receptor (pIgR) transports dimeric IgA and pentameric IgM across the intestinal epithelium.
• Antibodies mediated by pIgR are key to intestinal mucosal immune defense.

Purpose of the Study:

• To investigate the role of pIgR in maintaining gut homeostasis and its impact on the gut microbiota.
• To determine the effect of pIgR deficiency on the host's susceptibility to inflammatory conditions like colitis.

Main Methods:

• Gene expression profiling of colonic epithelial cells from pIgR knockout (KO) and wild-type (WT) mice.
• 16S rRNA gene sequencing for microbial community analysis.
• Assessment of dextran sulfate sodium (DSS)-induced colitis in pIgR KO and WT mice.

Main Results:

• pIgR KO mice exhibited differential expression of over 200 genes in colonic epithelial cells compared to WT mice.
• Upregulation of antimicrobial peptides in pIgR KO mice occurred in a commensal-dependent manner.
• pIgR deficiency led to altered gut microbiota composition and increased susceptibility to DSS-induced colitis.

Conclusions:

• pIgR is essential for the stability of the commensal gut microbiota.
• Disruption of pIgR function compromises gut homeostasis and exacerbates colitis.
• The absence of pIgR significantly worsens the outcome of experimental colitis, highlighting its critical role in mucosal immunity.