A ROS-responsive synergistic delivery system for combined immunotherapy and chemotherapy
Doudou Hu, Wei Zhang, Jiajia Xiang, Dongdong Li, Yong Chen, Pengcheng Yuan, Shiqun Shao, Zhuxian Zhou, Youqing Shen, Jianbin Tang
Abstract
Immune checkpoint blockade (ICB) therapies that target programmed cell death-1 (PD-1)/programmed cell death-ligand 1 (PD-L1) pathway are currently used for the treatment of various cancer types. However, low response rates of ICB remain the major issue and limit their applications in clinic. Here, we developed a ROS-responsive synergistic delivery system (pep-PAPM@PTX) by integrating physically-encapsulated paclitaxel (PTX) and surface-modified anti-PD-L1 peptide (pep) for combined chemotherapy and ICB therapy. Pep-PAPM@PTX could bind the cell surface PD-L1 and drive its recycling to lysosomal degradation, thus reverting PTX-induced PD-L1 upregulation and downregulating PD-L1 expression. As a result, pep-PAPM@PTX significantly promoted T cell infiltration and increased tumor immunoactivating factors, synergizing PTX chemotherapy to achieve enhanced anticancer potency in a triple-negative breast cancer (TNBC) model.