GSE202314
T cells produce interleukin-22 to promote CD155-driven lung metastasis
T cells are key players in immunosurveillance and anti-tumor immunity. However, subsets of T helper cells producing high levels of interleukin-22 (IL-22) accumulate in primary breast and lung tumors and are linked to a more dismal outcome. Here, we demonstrate that such TH22 cells promote metastasis by abrogating NK cell-mediated immune surveillance. Using mouse models of metastatic lung and breast cancer, we find that secreted IL-22 acts directly on disseminated cancer cells expressing the IL-22 receptor (IL-22R). In turn, IL-22 induces cancer cell overexpression of CD155, which binds to activating receptor CD226 on the surface of NK cells and triggers its downregulation. This functionally impairs NK cells to promote lung metastases. Importantly, neutralization of IL-22 in vivo blocked the metastatic potential of cancer cells, suggestive of therapeutic exploitability. We confirmed the paramount role of IL-22 signaling that was associated with CD155 expression in human datasets and marked poor patient outcomes. This study reveals an immunosuppressive feedback loop activated by T cell-derived IL-22 in cancer progression, creating the rationale for the development of future targeted therapeutics. Overall design: Assessment of differential gene expression of 4T1 cells after treatment with IL-22 in compatison to untreated cells. For each experimental condition, analysis was performed on three biological replicates.