After radiotherapy, dying cancer cells release mutated proteins, namely tumor-derived protein antigens (TDPAs). When immune cells are recruited to the tumor site, they can detect the TPDAs and train other immune cells to recognize and fight cancer in other parts of the body.
In a collaborative work researchers at the University of North Carolina at Chapel Hill (USA) have exploited this phenomenon to design a new strategy to improve cancer immunotherapy. They bound TDPAs on the surface of poly(lactic-co-glycolic acid) (PLGA) nanoparticles to enhance the response to immunotherapy. Indeed, the nanoparticles could capture the TDPAs and transport them to antigen-presenting cells such as dendritic cells, thus promoting cancer immunity. They observed 20% cure rate in a mouse model of melanoma treated with the antigen-capturing nanoparticles compared with 0% without treatment. This approach has a great potential to improve the efficiency of immunotherapy for the treatment of cancer by inducing the abscopal effect, a phenomenon in which the treatment of local tumor produces a systemic regression of metastases.