RESUMEN
Interleukin-12 (IL-12) holds significant potential in cancer therapy; however, its clinical applicability is hindered by dose-limiting toxicity. Delivery of the IL-12 gene directly to tumours for constitutive IL-12 expression is a possible strategy to enhance its effectiveness while minimizing systemic toxicity. In this study, we investigate the potential of red blood cell-derived extracellular vesicles (RBCEVs) as a carrier for Il-12 plasmid delivery. We demonstrate that RBCEVs can be loaded with minicircle plasmid encoding IL-12 and delivered to MB49 bladder cancer cells for IL-12 expression. The expression of transgenes from minicircles was significantly higher than from the parental plasmids. RBCEV-mediated IL-12 expression stimulated immune responses in mouse splenocytes. Intratumoral delivery of Il-12 plasmid-loaded RBCEVs suppressed bladder cancer tumour growth, stimulated immune responses and promoted immune cell infiltration. In conclusion, our study demonstrates the promising potential of RBCEVs as an effective, safe and redosable nucleic acid drug delivery platform for IL-12.
RESUMEN
Immunotherapy has emerged as a mainstay in cancer therapy, yet its efficacy is constrained by the risk of immune-related adverse events. In this study, we present a nanoparticle-based delivery system that enhances the therapeutic efficacy of immunomodulatory ligands while concurrently limiting systemic toxicity. We demonstrate that extracellular vesicles (EVs), lipid bilayer enclosed particles released by cells, can be efficiently engineered via inverse electron demand Diels-Alder (iEDDA)-mediated conjugation to display multiple immunomodulatory ligands on their surface. Display of immunomodulatory ligands on the EV surface conferred substantial enhancements in signaling efficacy, particularly for tumor necrosis factor receptor superfamily (TNFRSF) agonists, where the EV surface display served as an alternative FcγR-independent approach to induce ligand multimerization and efficient receptor crosslinking. EVs displaying a complementary combination of immunotherapeutic ligands were able to shift the tumor immune milieu toward an anti-tumorigenic phenotype and significantly suppress tumor burden and increase survival in multiple models of metastatic cancer to a greater extent than an equivalent dose of free ligands. In summary, we present an EV-based delivery platform for cancer immunotherapeutic ligands that facilitates superior anti-tumor responses at significantly lower doses with fewer side effects than is possible with conventional delivery approaches.
