PD-1 Blockade Cellular Vesicles for Cancer Immunotherapy

W. Sun, C. Wang, X. Zhang, J. Fine, Z. Gu, T. Wang, Y. Ye, H. Cheng, Q. Hu, P. Huang, B. Langworthy, G. Dotti (+2 others)
Cancer cells resist to the host immune antitumor response via multiple suppressive mechanisms, including the overexpression of PD-L1 that exhausts antigen-specific CD8+ T cells through PD-1 receptors. Checkpoint blockade antibodies against PD-1 or PD-L1 have shown unprecedented clinical responses. However, limited host response rate underlines the need to develop alternative engineering approaches. Here, engineered cellular nanovesicles (NVs) presenting PD-1 receptors on their membranes, which
more » ... r membranes, which enhance antitumor responses by disrupting the PD-1/PD-L1 immune inhibitory axis, are reported. PD-1 NVs exhibit a long circulation and can bind to the PD-L1 on melanoma cancer cells. Furthermore, 1-methyl-tryptophan, an inhibitor of indoleamine 2,3-dioxygenase can be loaded into the PD-1 NVs to synergistically disrupt another immune tolerance pathway in the tumor microenvironment. Additionally, PD-1 NVs remarkably increase the density of CD8+ tumor infiltrating lymphocytes in the tumor margin, which directly drive tumor regression.
doi:10.17615/0jyx-t214 fatcat:y763zmmvtrfy5j2wjsnabtnrta