T cell-mediated immunoregulation in the gastrointestinal tract

Area of Science:

• Gastroenterology
• Immunology
• Cell Biology

Background:

• The intestinal barrier faces constant exposure to antigens from commensal flora and diet.
• Maintaining immune tolerance while preventing pathogen invasion is crucial for gut health.
• Dysregulated immune responses in the gut can lead to inflammatory conditions.

Purpose of the Study:

• To review current knowledge on conventional and unconventional regulatory T cell subsets (Tregs).
• To emphasize clinical data on Treg function and dysfunction in major human gastrointestinal diseases.
• To compare findings from human clinical data with experimental animal models.

Main Methods:

• Literature review of regulatory T cell subsets in the intestinal mucosa.
• Analysis of clinical data related to inflammatory bowel diseases, coeliac disease, food allergy, and colorectal cancer.
• Synthesis of information on conventional (e.g., CD4+ CD25+ Foxp3+ T cells, Th3, Tr1) and unconventional (e.g., TCRgammadelta, TCRalphabeta CD8+ IELs) Tregs.

Main Results:

• Regulatory T cells play a complex role in intestinal immune homeostasis.
• Both conventional and unconventional T cell subsets exhibit regulatory functions in the gut.
• Clinical data provides partial validation for mechanisms identified in animal studies.

Conclusions:

• Regulatory T cells are critical for managing intestinal immune responses.
• Clinical evidence partially supports the role of Tregs in gastrointestinal diseases, but discrepancies with animal models exist.
• Further research is needed to fully elucidate Treg function in human gut pathologies.