Autoimmune host-microbiota interactions at barrier sites and beyond

Area of Science:

• Immunology
• Microbiome Research
• Autoimmunity

Background:

• The microbiota plays a crucial role in the pathogenesis of autoimmune diseases.
• Commensal microorganisms can have protective or detrimental effects on immunity in autoimmune models.
• Human microbiome studies suggest dysbiosis is linked to autoimmune conditions, but mechanisms remain unclear.

Purpose of the Study:

• To review the current literature on the role of the microbiota in autoimmunity.
• To propose mechanisms by which the microbiota mediates autoimmune responses.
• To identify outstanding questions in the field of microbiome and autoimmunity.

Main Methods:

• Literature review of existing studies on microbiota and autoimmunity.
• Analysis of immune-commensal interactions in humanized gnotobiotic models.
• Exploration of proposed mechanisms: bystander activation, epitope spread, and cross-reactivity.

Main Results:

• The microbiota significantly impacts both innate and adaptive immunity.
• Animal models show varied effects of commensals on autoimmunity.
• Human studies indicate a correlation between dysbiosis and autoimmune diseases.

Conclusions:

• The microbiota is proposed to mediate autoimmunity through mechanisms similar to infectious agents.
• Key proposed mechanisms include bystander activation, epitope spread, and cross-reactivity.
• Further research is needed to elucidate the precise mechanisms of microbiota-mediated autoimmunity.