Comprehensive genomic analysis of CD4 T cell subtypes infiltrating human triple-negative breast cancer

Triple-negative breast cancer is a typical molecular subtype of breast cancer that lacks the expression of estrogen receptor, progesterone receptor and human epidermal growth factor receptor 2 which is also well known for its aggressive and metastatic clinical characteristics. Currently, no specific targeted therapy is available for TNBC. CD4+ T cells are critical regulators of immune responses but their role in breast cancer is currently unknown. Therefore, we investigated the gene expression profile of tumor infiltrating CD4+ T cells and to predict their potential roles in modulating antitumor immune function. As a result, abundant Treg and exhausted lymphocytes were detected, accompanied by largely decreased of effector/memory and cytotoxic T cells. The study is composed of 2 groups, CD4 T cells from primary tumors and peripheral blood (n=2). All triple-negative breast cancer patients were treatment naive. Cells were flow sorted and purity of cells were at least 95%.