To enhance the abscopal effect of radiotherapy, Min et al. designed PLGA-based nanoparticles capable of capturing antigens released by radiolysis of tumor cells and delivering these antigens to antigen-presenting cells. Injected into a tumor prior to radiation, the particles enhanced distant tumor control and provided long-term protection.

Immunotherapy holds tremendous promise for improving cancer treatment. To administer radiotherapy with immunotherapy has been shown to improve immune responses and can elicit the 'abscopal effect'. Unfortunately, response rates for this strategy remain low. Herein we report an improved cancer immunotherapy approach that utilizes antigen-capturing nanoparticles (AC-NPs). We engineered several AC-NP formulations and demonstrated that the set of protein antigens captured by each AC-NP formulation is dependent on the NP surface properties. We showed that AC-NPs deliver tumour-specific proteins to antigen-presenting cells (APCs) and significantly improve the efficacy of alphaPD-1 (anti-programmed cell death 1) treatment using the B16F10 melanoma model, generating up to a 20% cure rate compared with 0% without AC-NPs. Mechanistic studies revealed that AC-NPs induced an expansion of CD8+ cytotoxic T cells and increased both CD4+T/Treg and CD8+T/Treg ratios (Treg, regulatory T cells). Our work presents a novel strategy to improve cancer immunotherapy with nanotechnology.

Author Info: (1) Laboratory of Nano- and Translational Medicine, Carolina Center for Cancer Nanotechnology Excellence, Carolina Institute of Nanomedicine, University of North Carolina at Chapel

Author Info: (1) Laboratory of Nano- and Translational Medicine, Carolina Center for Cancer Nanotechnology Excellence, Carolina Institute of Nanomedicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA. Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA. Department of Radiation Oncology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA. (2) Laboratory of Nano- and Translational Medicine, Carolina Center for Cancer Nanotechnology Excellence, Carolina Institute of Nanomedicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA. Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA. Department of Radiation Oncology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA. (3) Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA. Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA. (4) Laboratory of Nano- and Translational Medicine, Carolina Center for Cancer Nanotechnology Excellence, Carolina Institute of Nanomedicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA. Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA. Department of Radiation Oncology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA. (5) Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA. Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA. (6) Laboratory of Nano- and Translational Medicine, Carolina Center for Cancer Nanotechnology Excellence, Carolina Institute of Nanomedicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA. Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA. Department of Radiation Oncology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA. (7) Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA. Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA. (8) UNC Proteomics Core Facility, Department of Pharmacology, University of North Carolina, Chapel Hill, North Carolina 27599, USA. (9) Jiangsu Center for the Collaboration and Innovation of Cancer Biotherapy, Cancer Institute, Xuzhou Medical University, Xuzhou, Jiangsu 221004, China. (10) Division of Medical Oncology, Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710, USA. (11) Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA. Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA. Division of Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina 27599, USA. Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599, USA. Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695, USA. Sloan-Kettering Institute for Cancer Research, Memorial Sloan-Kettering Cancer Center, New York, New York 10021, USA. (12) Laboratory of Nano- and Translational Medicine, Carolina Center for Cancer Nanotechnology Excellence, Carolina Institute of Nanomedicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA. Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA. Department of Radiation Oncology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA. (13) Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA. Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA. (14) Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA. Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA. Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA. (15) Laboratory of Nano- and Translational Medicine, Carolina Center for Cancer Nanotechnology Excellence, Carolina Institute of Nanomedicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA. Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA. Department of Radiation Oncology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA. Jiangsu Center for the Collaboration and Innovation of Cancer Biotherapy, Cancer Institute, Xuzhou Medical University, Xuzhou, Jiangsu 221004, China.