IMMUNOLOGY2025™ Conference Recordings-Gut commensal translocation in extraintestinal autoimmunity

Gut commensal translocation in extraintestinal autoimmunity

Video Transcription

Video Summary

The speaker discussed how gut and oral microbes may contribute to systemic autoimmunity, especially lupus and antiphospholipid syndrome. Three main ideas were highlighted: molecular cross-reactivity, relocation of commensals from the mouth to the gut, and translocation of gut bacteria into lymphoid organs. The lab focused on autoantigens such as Ro60 and beta-2-glycoprotein-1, showing that several commensal bacteria express Ro60 orthologs that can trigger cross-reactive immune responses. They proposed that certain microbes may relocate to the wrong niche or translocate across the gut barrier, especially in genetically predisposed hosts. In mouse and human studies, Enterococcus gallinarum was shown to cross the gut barrier, alter intraepithelial lymphocytes, activate TLR8, and promote Th17 and autoantibody responses. The speaker argued that microbiota, genetics, and environmental factors like UV light may together drive chronic autoimmune disease.

Keywords

gut microbiota

oral microbes

systemic autoimmunity

lupus

antiphospholipid syndrome

molecular cross-reactivity