CRTAM Protects Against Intestinal Dysbiosis During Pathogenic Parasitic Infection by Enabling Th17 Maturation

Area of Science:

• Immunology
• Microbiology
• Gastroenterology

Background:

• The gastrointestinal tract harbors a vast microbial community, and infections can lead to dysbiosis.
• Intestinal infections, such as with Toxoplasma gondii, disrupt the gut microbiota and immune homeostasis.
• Host resistance to T. gondii relies on Th1 and Th17 immune responses, but the role of Th17 cells is not fully understood.

Purpose of the Study:

• To investigate the role of Th17 cells in the host response to Toxoplasma gondii infection.
• To determine the contribution of class I-restricted T cell-associated molecule (CRTAM) to T. gondii-induced immune responses.
• To elucidate the mechanisms by which Th17 cells influence intestinal barrier function and immunopathology during infection.

Main Methods:

• Analysis of T cell responses, including cytokine production (IL-17) and surface molecule expression (CRTAM) during T. gondii infection.
• Assessment of intestinal barrier integrity and bacterial translocation using molecular and microbiological techniques.
• Evaluation of immunopathology in the context of varying IL-17 levels.

Main Results:

• CRTAM expression on T cells is essential for optimal IL-17 production during T. gondii infection.
• A deficiency in IL-17 leads to increased immunopathology.
• Impaired antimicrobial peptide production and increased bacterial translocation to mesenteric lymph nodes and spleen were observed in the absence of IL-17.

Conclusions:

• CRTAM-mediated IL-17 production is a critical component of the host defense against T. gondii.
• IL-17 plays a protective role by maintaining intestinal barrier function and limiting bacterial translocation.
• Dysbiosis and impaired immune responses during T. gondii infection highlight the importance of Th17 cell function in gut health.