Abstract 3418: IL6/1 fusion cytokine as a novel adjuvant for manufacturing of T cells for the treatment of ovarian cancer

Background: Autologous adoptive T cell therapy (ACT) is an emerging approach for the treatment of ovarian cancer. ACT is more effective if T cells manufactured ex vivo exhibit memory phenotype rather than exhaustive. IL-6 cytokine is known to effect T cell activation, proliferation, survival, and polarization whereas IL-1β is known to augment in vivo expansion of antigen-primed CD8 and CD4 T cells, CD8+ T cell compartmentalization, and activation of T cells by antigen presenting dendritic cells. Due to known effects of these cytokines, we developed a novel biological product, IL6/1, a chimera of IL-6 and IL-1β, for effective manufacturing of T cells for ACT against ovarian cancer. We demonstrate that manufacturing of modified T cells with IL6/1 fusion cytokine improves T cell biological properties and hope to improve success of ACT in ovarian cancer. Methods: Media from the HEK293 cells lentivirally transduced with IL6/1 was used to purify and characterize the fusokine. T cells were isolated from healthy donor PBMCs by negative selection and activated with IL2, anti CD3 - CD28 beads in the presence IL6, IL1β, IL6 + IL1β, IL6/1, conditional media, or no treatment control. Flow cytometry was used to monitor (a) T cell proliferation, (b) expression of CD45Ra, CD45Ro, CD3, CD4 and CD8 to define T cell phenotype and (c) assess cell death by labeling with annexin V and DAPI. Western blotting was performed to study the mechanism of action of IL6/1. Two-way ANOVA was used for statistical analysis. Results: IL6/1 enhanced human T cell survival and increased the CD4 and CD8 memory (CD45Ro+) T cells as compared to vehicle controls or T cells exposed to IL6 or IL1β. T cells exposed to IL6/1 also showed a 10-15% increase in protection from cell death and apoptosis as compared to vehicle controls and T cells exposed to IL-6 or IL1β. Western blotting showed an increase in phosphorylation of STAT3, suggesting the involvement of this key signaling molecule in IL6/1-mediated T cell activation. Conclusion: These findings suggest that IL6/1 fusion cytokine holds promise as a novel adjuvant for increasing the efficacy of T cell manufacturing for therapy in ovarian cancer. Overall, the IL6/1 fusion cytokine represents a novel approach to promote T cell survival, and memory T cell proliferation. Ongoing studies are focusing on evaluating the efficacy of IL6/1-based adjuvants in combination with ACT for the treatment of ovarian cancer in relevant mouse models. Citation Format: Sejal Tarun Sharma, Rahul Das, Lisa Barroilhet, Manish Patankar, Jacques Galipeau. IL6/1 fusion cytokine as a novel adjuvant for manufacturing of T cells for the treatment of ovarian cancer [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 3418.