Gene-guided OX40L anchoring to tumor cells for synergetic tumor “self-killing” immunotherapy
Lin Lin, Yingying Hu, Zhaopei Guo, Jie Chen, Pingjie Sun, Huayu Tian, Xuesi Chen
Abstract
The low objective response rates and severe side effects largely limit the clinical outcomes of immune checkpoint blockade (ICB) therapy. Here, a tumor “self-killing” therapy based on gene-guided OX40L anchoring to tumor cell membrane was reported to boost ICB therapy. We developed a highly efficient delivery system HA/PEI-KT (HKT) to co-deliver the OX40L plasmids and unmethylated CG-enriched oligodeoxynucleotide (CpG). On the one hand, CpG induced the expression of OX40 on T cells within tumors. On the other hand, OX40L plasmids achieved the OX40L anchoring on the tumor cell membrane to next promote T cells responses via OX40/OX40L axis. Such synergistic tumor “self-killing” strategy finally turned “cold” tumors to “hot”, to sensitize tumors to programmed cell death protein 1/programmed cell death ligand 1 (PD-1/PD-L1) blockade therapy, and promoted an immune-mediated tumor regression in both B16F10 and 4T1 tumor models, with prevention of tumor recurrence and metastasis. To avoid the side effects, the gene-guided OX40L anchoring and PD-L1 silencing was proposed to replace the existing antibody therapy, which showed negligible toxicity in vivo. Our work provided a new possibility for tumor “self-killing” immunotherapy to treated various solid tumors.