BRAF-targeted therapy alters the functions of intratumoral CD4+ T cells to inhibit melanoma progression

The establishment of an immunosuppressive tumor microenvironment is a hallmark feature driving cancer cell evasion of immunosurveillance. In a murine melanoma model, we recently demonstrated that decreased intratumoral CD4(+) T-cell expression of CD40L and interferon gamma (IFN gamma) is critical to maintain this immunosuppressive microenvironment. Altered effector functions of tumor-associated CD4(+) T cells is essential for B-Raf(V600E) inhibitor-mediated restoration of antitumor immunity.