Abstract 7: Ginsenoside Rb1 delays the senescence of CD8+ T cells to expand T cells with superior antitumor immunity

Abstract Background and Objective: Immunosenescence represents a distinct state of T cell dysfunction in the TME, and plays crucial role in many age-related diseases including tumor. Senescent cell removal by senolytic agents or therapies that inhibit the SASP have demonstrated benefit in both preclinical and clinical models of geriatric decline and chronic diseases. Here, we aimed to screen anti-aging compounds to delay T-cell senescence in TME, and explore novel strategies of reversing tumor induced T-cell senescence to restore antitumor immunity. Methods and Results: Using in vitro senescence inducing system, we screened ginsenoside Rb1 from 22 anti-aging compounds as the compound that had the most effective activity to reduce CD8+ T cell senescence, displayed as decreased β-gal, p16, and p21. Further analysis showed that ginsenoside Rb1 promoted anti-CD3/CD28-induced TCR signaling and the secretion of effector cytokines IFN-γ, TNF-α and IL -2 in OTI T cells. Intriguingly, ginsenoside Rb1 treatment significantly increased TCF-1 in CD8+ T cells, and ginsenoside Rb1 treated OT-I T cells significantly inhibited tumor growth. Moreover, ginsenoside Rb1 greatly enhanced the efficiency of CD19-CART cells to kill Namalwa tumor cells. Conclusion: Ginsenoside Rb1 delays T cell senescence and enhances T cell antitumor activity. This data provides a new insight into T cell based antitumor therapy. Citation Format: Chunhong Ma, Xue Sheng, Chunyang Li. Ginsenoside Rb1 delays the senescence of CD8+ T cells to expand T cells with superior antitumor immunity abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts) ; 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84 (6Suppl): Abstract nr 7.