Triple-negative breast cancer (TNBC) is the most aggressive type of breast cancer and therapies are primarily limited to conventional chemotherapy. TNBC patients who respond to neo-adjuvant chemotherapy with a pathological complete response (pCR) have excellent 5-year survival (up to 94%). However, this represents the minority of TNBC patients (25-40%). The remainder of patients have less than 60% 5-year survival due to aggressive relapse. Therefore, increasing the pCR rate of chemotherapy in TNBC holds great promise for improving survival. Recently, we have gained preliminary data that chemotreatment can induce enhanced CD3+ T cell infiltration into a TNBC mammary tumor model. Herein we propose to study the potential for T cell-activating therapies, such as anti-CTLA4 and anti-PD1 antibodies, to enhance the response to chemotherapy in TNBC.