B16 Membrane-Coated Vesicles for Combined Photodynamic Therapy and Immunotherapy Shift Immune Microenvironment of Melanoma

Abstract

Yuqian Wang,1,* Zhilong Zhao,2,* Chenlu Liu,3 Miao Hao,1 Chenfei Kong,1 Xiaoming Zhao,1 Yiyao Gao,1 Yucheng Zhang,1 Wanxing Cui,4 Congxiao Zhang,2 Jinlan Jiang1 1Scientific Research Center, China-Japan Union Hospital, Jilin University, Changchun, 130031, People’s Republic of China; 2Department of Stomatology, The First Hospital of Jilin University, Changchun, 130031, People’s Republic of China; 3Biobank, China-Japan Union Hospital, Jilin University, Changchun, 130031, People’s Republic of China; 4Medstar Georgetown Transplant Institute, Georgetown University Hospital, Washington, DC, 20007, USA*These authors contributed equally to this workCorrespondence: Congxiao Zhang; Jinlan Jiang, Email [email protected]; [email protected]: Coating of nanomedicine with cell membranes has attracted increasing attention as it can boost biocompatibility and improve the efficiency of treatment. Herein, we prepared innovative tumor cell-membrane-coated vesicles based on photodynamic therapy (PDT) drug indocyanine green (ICG) and explore the effect on melanoma in vitro and in vivo.Methods: ICG was coated with B16 cell membranes (I@BM NVs) by sonication and extrusion, and the morphological characteristics of I@BM NVs were evaluated by transmission electron microscopy (TEM) and NP-tracking analysis. Homologous cellular uptake was evaluated by flow cytometry (FCM) after staining by DiD dye. Cellular cytotoxicity was evaluated by cell counting kit-8 assay and the anti-tumor effect in vitro was assessed by FCM and western blotting. The anti-tumor effect in vivo was evaluated in a B16 xenograft model in mice. The tumor micro-environment was investigated by FCM and real-time PCR.Results: The vesicles are stable and uniform in nature, and show strong homologous targeting in vivo and in vitro. The vesicles can generate reactive oxygen species to induce apoptosis of B16 cells under near-infrared irradiation. Furthermore, the I@BM NVs induce a significant anti-tumor response in vivo, and perform better with respect to both tumor growth inhibition and lifespan extension. Analysis of immunocytes in the tumor microenvironment showed significant reductions in numbers of myeloid-derived suppressor cells and tumor-associated M2 macrophages in mice in the I@BM NVs group. This was accompanied by significant increases in numbers of M1 macrophages and proliferative CD4+/CD8+ T cells. Expression levels of IFN-γ and IL-2 increased in the I@BM NVs group, while expression of TGF-β and IL-10 decreased.Conclusion: The results show that the I@BM NVs are feasible drugs for the treatment of melanoma by inducing cell apoptosis under NIR and shifting the immunosuppressive tumor microenvironment in vivo.Graphical Abstract: Keywords: melanoma, vesicles, tumor microenvironment, photodynamic therapy, immunotherapy

Keywords

• melanoma
• vesicles
• tumor microenvironment
• photodynamic therapy
• immunotherapy