An Engineered Cytokine-Induced Killer Cell-Derived Nanovesicle Featuring Multiplexed Immune Activation Performances for Enhanced Tumor Therapy.

In this study, a multiplexed immune activation strategy is elaborately developed based on engineered cytokine-induced killer (CIK) cell-nanovesicles (DOX@CpG-PNVs) with high tumor targeting, tumor killing and immunostimulatory functions for enhanced antitumor therapy. CIK-derived cellular nanovesicles enriched with outer-membrane molecules (e.g., FasL, TRAIL, and tumor chemokine receptors) are genetically engineered with the expression of programmed death-1 (PD-1), and further loaded with doxorubicin (DOX) and CpG ODN adjuvant to obtain DOX@CpG-PNVs. Specifically, this unique designed nanovesicle harnesses the dual therapeutic characteristics: i) multiple immune activation, including PD-1/PD-L1 blockade to rescue cytotoxic T lymphocyte function, CpG-mediated non-MHC-restricted immunostimulation, and DOX-induced immunogenic cell death; ii) direct tumor cell killing triggered by DOX and apoptosis-inducing ligands of FasL/TRAIL. Having killed tumor cells via multiple ways, DOX@CpG-PNVs exhibited significant anti-tumor effect, as evidenced on both immunogenic and poorly immunogenic tumors. Even in a poorly immunogenic tumor model, DOX@CpG-PNVs achieves a tumor suppression rate of 75%. Such a synergistic approach cooperatively compensates for the defects of a single-mode immunotherapy and overcomes the immunosuppressive milieu, offering a feasible bioactive material-based strategy for treating various types of tumors.