AUTHOR=Fu Qiang , Shen Qian , Tong Jin , Huang Liu , Cheng Yi , Zhong Wei TITLE=Anti-Tumor Necrosis Factor Receptor 2 Antibody Combined With Anti-PD-L1 Therapy Exerts Robust Antitumor Effects in Breast Cancer JOURNAL=Frontiers in Cell and Developmental Biology VOLUME=Volume 9 - 2021 YEAR=2021 URL=https://www.frontiersin.org/journals/cell-and-developmental-biology/articles/10.3389/fcell.2021.720472 DOI=10.3389/fcell.2021.720472 ISSN=2296-634X ABSTRACT=Breast cancer is the most common female malignant tumor and a public health challenge in the world. In this study, we demonstrate that tumor necrosis factor receptor 2 (TNFR2) is highly expressed in both breast tumor tissue and by tumor-infiltrating immunosuppressive CD4+CD25+FoxP3+ regulatory T cells (Tregs). We show dose-escalating concentrations of a TNFR2 antagonistic antibody reduced the inhibitory effect of Tregs on CD4+CD25- T cells (Teffs). Anti-TNFR2 therapy inhibits 4T1 tumor growth in vivo, elongates tumor bearing mice survival and develop 4T1-specific immune response. Moreover, our data indicates anti-TNFR2 antibody combined with anti-PD-L1 therapy exert more efficiently than anti-TNFR2 or anti-PD-L1 therapy single agent treatment. This research suggests TNFR2 antagonism could potentially offer a clinical benefit as a single agent and/or in combination with anti-PD-L1 treatment in breast cancer therapy.