TRIM58 Restrains Intestinal Mucosal Inflammation by Negatively Regulating TLR2 in Myeloid Cells.

Area of Science:

• Immunology
• Molecular Biology
• Gastroenterology

Background:

• Balanced innate immune signaling in the intestine is vital for host defense and preventing mucosal injury during inflammation.
• Toll-like receptor 2 (TLR2) plays a significant role in intestinal immune responses.

Purpose of the Study:

• To investigate the role of TRIM58 in regulating TLR2-mediated innate immune signaling in the gut.
• To determine the impact of TRIM58 deficiency on experimental colitis and its potential contribution to ulcerative colitis.

Main Methods:

• Yeast two-hybrid screening and co-immunoprecipitation to identify TRIM58-TLR2 interaction.
• Analysis of TRIM58 expression in myeloid cells and its modulation by TLR2 ligands.
• Overexpression and genetic deletion (whole-body and myeloid-specific) of TRIM58 in mouse models of colitis.
• In vitro studies on myeloid cell responses to inflammatory stimuli.
• Assessment of TRIM58 and TLR2 levels in human ulcerative colitis specimens.

Main Results:

• TRIM58 interacts with TLR2 and, when overexpressed, promotes TLR2 degradation, inhibiting its signaling.
• TRIM58 deficiency in mice leads to exacerbated dextran sodium sulfate-induced colitis with increased TLR2 expression and inflammation.
• Myeloid cell-specific TRIM58 deletion accelerates colitis, indicating the compartment's critical role.
• TRIM58-deficient myeloid cells exhibit constitutive TLR2 upregulation and overproduction of IL-1β in response to inflammatory cytokines.
• Reduced TRIM58 expression is observed in colonic tissues from ulcerative colitis patients.

Conclusions:

• TRIM58 acts as a novel negative regulator of innate immunity and mucosal homeostasis by controlling TLR2 signaling.
• Dysfunctional TRIM58 in myeloid cells is implicated in the pathogenesis of ulcerative colitis.