Interleukin-33, a Potential Cytokine Expressed in the Tumor Microenvironment Is Involved in Antitumor Immunotherapy Through Facilitating CD8+ T Cells

Interleukin-33 (IL-33) is a cytokine with pleiotropic functions in various diseases; however, its role in the antitumor immune response is still unclear. We found the expression of IL-33/ST2 in nonsmall cell lung tumor microenvironment. Furthermore, we found that IL-33 promoted effector functions of CD8+ T cells that play a critical role in antitumor immune response. In addition, we found that IL-33 enhanced tumor vaccine effector functions in mice. Altogether, these findings suggest that IL-33, through facilitates CD8+ T cells in microenvironment to provide a profound effect in antitumor immunotherapy.