Ablation of IL-17A abrogates progression of spontaneous intestinal tumorigenesis

Area of Science:

• Immunology
• Gastroenterology
• Oncology

Background:

• The role of endogenous Interleukin-17A (IL-17A) in spontaneous intestinal tumorigenesis remains largely unexplored.
• Adenomatous polyposis coli (APC) gene mutations are a common driver of intestinal cancer, and Apc(Min/+) mice serve as a model for studying this process.

Purpose of the Study:

• To investigate the intrinsic role of IL-17A in spontaneous intestinal tumor development in Apc(Min/+) mice.
• To elucidate the impact of IL-17A on immune cell function and intestinal architecture during tumorigenesis.

Main Methods:

• Utilized Apc(Min/+) mice with and without IL-17A ablation.
• Assessed tumor development, inflammatory markers, immune cell infiltration, and intestinal histology.
• Analyzed CD4 T cell proliferation, cytokine production, regulatory T cell resistance, and pathogenicity via adoptive transfer.

Main Results:

• IL-17A ablation significantly reduced intestinal tumor burden in Apc(Min/+) mice.
• Absence of IL-17A decreased inflammatory cytokines, reduced lymphocyte infiltration, and preserved intestinal architecture.
• CD4 T cells from Apc(Min/+) mice exhibited hyperproliferation, increased IL-17A and IL-10, resistance to suppression, and induced colitis, effects abolished by IL-17A ablation.

Conclusions:

• CD4 T cell-derived IL-17A is a key promoter of spontaneous intestinal tumorigenesis in Apc(Min/+) mice.
• IL-17A contributes to tumor development by altering CD4 T cell function and promoting an inflammatory microenvironment.
• Targeting IL-17A may represent a therapeutic strategy for intestinal cancers associated with APC mutations.