Abstract 2793: The role of IL-10 in obesity-induced T-cell polarization in the prostate tumor microenvironment

Background: Prostate cancer remains the second leading cause of cancer related deaths in men and obesity has been shown to severely impact its prognosis. Previous studies in our laboratory have shown that CD4+ T cells polarized under obese conditions are prostate cancer promoting and that this is due in part to suppression of IFNγ and induction of IL-6 in the T cells. Objective: The goal of this study is to determine the role of IL-10 in mediating the impact of obese conditions on T cell phenotype. Methods: A series of in vitro studies were conducted to evaluate the effects of obesity on T cell function and polarization. Splenic CD4+ T-cells from 10-week-old, male, C57BI/6 mice were isolated and stimulated with anti-CD3+/CD28+ antibodies under obese conditions. Gene expression was measured using qPCR and AKT phosphorylation was measured using Western blot analysis. In vivo T-cell function was compared between obese and non-obese male mice. Deletion assays were used to determine the role of IL-10 in mediating the effects observed on T cell phenotype in response to obese conditions. Results: For both the in vitro and in vivo studies, obese conditions suppressed the expression of Th1 biomarkers (IFNγ, IL-2, and T-bet) and upregulated the expression of Th2 biomarkers (IL-6, IL-10, and GATA-3) in CD4+ T cells. Likewise, obese conditions in vitro and in vivo were associated with decreased AKT phosphorylation. Studies are on-going to determine whether inhibiting the IL-10 pathway restores proper T cell activation under obese conditions. Conclusion: Obesity induces T cell dysfunction characterized by a Th1 to Th2 phenotypic shift, resulting in a pro-tumorigenic phenotype, potentially mediated by paracrine IL-10 signaling. These results are important in understanding the mechanisms by which obesity promotes a more aggressive disease, thereby identifying potential targets for improving outcomes. The results from these studies will provide a better understanding of the role of IL-10 as a novel target for preventing prostate cancer in obese subjects and improving overall survival. Citation Format: Margaret Kappel, Michael Adkison, Alejandra De Angulo, Peyton Travis, Brittany Harlow, Christopher Jolly, Linda deGraffenried. The role of IL-10 in obesity-induced T-cell polarization in the prostate tumor microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2793.