Abstract 6592: Deciphering the effects of age on T cell immunity and immunotherapy

Abstract Aging induces profound alterations in host biology and correlates with unfavorable clinical outcomes in age-related diseases such as cancer. While the pivotal role of the immune system in regulating tumor progression is well-acknowledged, the precise mechanisms through which aging influences anti-tumor T cell immunity and responsiveness to immune checkpoint blockade (ICB) remain elusive. In this study, we employed syngeneic murine tumor models (B16, MC38, and E0771) in young (2-4 months) and aged (20-24 months) cohorts to elucidate the early impacts of aging on tumor development and T cell responses. Our findings demonstrate that aged mice exhibit accelerated tumor growth across various models. In-depth analysis of tumor-infiltrating lymphocytes (TILs) uncovered distinct alterations in the CD8+ T cell population, characterized by decreased activation status and diminished tumor specificity in aged mice. Correspondingly, aged mice exhibited resistance to anti-PD-1 immunotherapy. To unravel the underlying environmental factors contributing to compromised anti-tumor T cell responses and ICB resistance, we characterized the immune and metabolic landscapes of the aged tumor-draining lymph nodes and tumors. Furthermore, we established a genetically engineered mouse model of lung adenocarcinoma in both young and aged mice, unveiling novel functions and mechanisms associated with age-related T cells actively impeding effective tumor control. In the context of increasing average life expectancy, comprehending the intricate interplay between age-related T cell dysfunction and cancer assumes paramount importance. Such insights hold the key to the development of innovative therapeutic strategies tailored for the growing population of older patients. Citation Format: SeongJun Han, Peter Georgiev, Jaime Schneider, Amy Huang, Zhanel Nugmanova, Thao H. Nguyen, Conghui Yao, Sheila Johnson, Shakchhi Joshi, Ishita Dhiman, Jefte M. Drijvers, Megan Fung, Jared H. Rowe, Brian C. Miller, Gordon J. Freeman, Alison E. Ringel, Marcia C. Haigis, Arlene H. Sharpe. Deciphering the effects of age on T cell immunity and immunotherapy 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 6592.