Human intestinal B cells in inflammatory diseases.

Area of Science:

• Immunology
• Gastroenterology
• Microbiome research

Background:

• The intestinal lumen hosts a complex microbial community influencing the gut immune system from birth.
• A balanced immune response is essential for pathogen defense, food tolerance, and preventing inflammation.
• B cells play a pivotal role in maintaining intestinal homeostasis and immune defense.

Purpose of the Study:

• To review the multifaceted roles of intestinal B cells in maintaining gut health.
• To explore the contribution of B cells to immune cell specialization within the gut.
• To discuss the involvement of intestinal B cells in the pathogenesis of inflammatory diseases.

Main Methods:

• Literature review of studies on intestinal B cells and the gut immune system.
• Analysis of B cell subsets, IgA secretion, and microenvironmental niches.
• Examination of the link between B cell dysfunction and inflammatory conditions.

Main Results:

• B cells are central to adaptive immunity in the gut, generating the largest IgA-secreting plasma cell population.
• The gut microenvironment, enriched in germinal centers, supports B cell maturation and T follicular helper cell function.
• Specific B cell subsets, like marginal zone B cells, develop and mature in the gut-associated lymphoid tissue.
• Loss of intestinal immune homeostasis involving B cells is linked to inflammatory diseases.

Conclusions:

• Intestinal B cells are critical for barrier integrity and immune tolerance.
• Imbalances in B cell function and gut microbiota can precipitate inflammatory disorders.
• Understanding intestinal B cell dynamics is key to developing therapies for gut and systemic inflammation.