Engineering irradiated tumor-derived microparticles as personalized vaccines to enhance antitumor immunity
The inadequate activation of antigen-presenting cells, the entanglement of T cells, and the highly immunosuppressive conditions in the tumor microenvironment (TME) are important factors that limit the effect of cancer vaccines. Studies have shown that individualized and broad antigens can fully activate anti-tumor immunity and inhibiting the function of TGF-ß can facilitate T cell migration to tumor sites. Based on our previous study, we introduced a new vaccine strategy by engineering irradiated tumor cell-derived microparticles (RT-MPs), which have both individualized and broad antigens, to induce broad antitumor effects and cause immunogenic death. Encouraged by the proinflammatory effects of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein and the high affinity between TGF-ßR2 and TGF-ß, we developed RT-MPs with the SARS-CoV-2 spike protein and TGF-ßR2. We found that this spike protein and high TGF-ßR2 expression induces the innate immune response and ameliorates the immunosuppressive TME, thereby promoting T cell activation and infiltration, and ultimately inhibiting tumor growth. In addition, when combined with anti-programmed death 1 (anti-PD-1) the engineered RT-MPs were able to generate an immune memory response and eliminate subcutaneous tumors. Our study provides a novel strategy for producing an effective personalized anti-tumor vaccine for clinical application. Overall design: Comparative gene expression profiling analysis of RNA-seq data for bone marrow derived macrophages which treated with RT-MPs or RT-MPs@S