Abstract 6571: Natural killer cell-derived exosomes encapsulated with IL-12 as nanocarriers for cancer immunotherapy

Abstract Cold tumors, owing to poor immune cell infiltration, immunosuppressive tumor microenvironment (TME) and low immunogenicity, are marked as a therapeutic challenge in cancer. Immunomodulatory cytokines showed encouraging outcomes in clinical settings by converting TME more immunoresponsive. Among the cytokines, IL-12 has drawn attention for its role in bridging innate and adaptive immunity, by inducing the proliferation and activation of NK and T cells. IL-12 enhances antigen-specific cell-mediated immunity by promoting Th1 immunity that in turn boosts IFN-γ production and inhibits angiogenesis. It also drives M2 to M1 macrophage polarization, enhances the infiltration of tumor-targeting immune cells, and depletes immunosuppressive cells. This action is critical in converting "cold" into "hot" tumors, making them more susceptible to immunotherapy. Additionally, IL-12 has a short plasma half-life and shows systemic toxicity which limits its use in clinical settings. We aim to deliver IL-12 encapsulating inside NK cell derived nanovesicle (NKnvs) which will bring many attributes- small size of NKnvs will facilitate better tumor accumulation, encapsulation will enhance the plasma half-life of IL-12, slow release of payload will-lower the dose-limiting systemic toxicity, NKnvs will carry cytotoxic proteins, miRNAs, and cytokines with tumor-killing and immunomodulatory properties. NKnvs was isolated by differential ultracentrifugation method, the purity of the isolated NKnvs was determined by Western blot. NTA, DLS and SEM was performed to determine the concentration, size and morphology of NKnvs. Next, IL-12 was encapsulated inside NKnvs by probe sonication method and the loading percentage was quantified by ELISA. To visualise the accumulation of NKnvs in different tissues and to determine the plasma half-life, NKnvs was labelled with DiI dye and purified by size exclusion chromatography. NKnvs showed the hydrodynamic radius and zeta potential of 189±20.61 nm and -10.5±10.1 mV respectively. SEM confirmed the spherical morphology of NKnvs. Loading percentage of IL-12 inside NKnvs was found 20.5±0.5 %. NKnvs induced activation and polarization of immune cells, enhancing tumor cell killing. Pharmacokinetic analysis indicated that NKnvs extended the half-life of the payload. The biodistribution study revealed that DiI labelled NKnvs showed enhanced tumor accumulation which also increased till 48 hrs. In conclusion, the developed nanoformulation offers a promising strategy to target the tumor microenvironment, improving therapeutic efficacy and reducing systemic toxicity. Further, the efficacy of immunovesicle (IL-12 NKnvs) can be explored in-vivo to determine the further therapeutic benefits associated with the developed nanoformulation. Citation Format: Monu Pandey, Vidit Gaur, Jayanta Bhattacharyya. Natural killer cell-derived exosomes encapsulated with IL-12 as nanocarriers for cancer immunotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 6571.