Abstract 6805: CD81 and CD82 in tumor infiltrating lymphocytes within the NSCLC tumor microenvironment play a crucial role in T cell activation and cytokine production

Abstract Background: The role of tetraspanins, particularly CD81 and CD82, in T cell activation, shedding light on their contribution to anti-tumor effects in the tumor microenvironment. The findings provide insights for potential applications of these tetraspanins in immunotherapy. Method: The study employed 10x Genomics for single-cell RNA sequencing and processed the data using Seurat. It focused on the tumor microenvironment, categorizing cell types, especially TIL subsets. T cells were sorted based on CD81 and CD82 expression and activated, and their activation markers and cytokine production were analyzed. Bulk RNA sequencing was performed on both sorted T cells and tumor samples, and the TCR repertoire was examined. Cytotoxicity of CD81 and CD82 transduced cells was measured using the xCELLigence RTCA HT system. Result: Tetraspanins have been linked to T cell co-stimulation and activation, with CD81 and CD82 playing a significant role in TCR signaling and activation. Single-cell and bulk RNA sequencing data from lung cancer patients reveal high expression of CD81 and CD82 in the tumor microenvironment, especially in T cells, correlating with T cell activation and cytokine production. In vitro experiments confirm the activation and effector cytokines, especially IFN-γ, TNF-α, and IL-2, producing potential of T cells expressing CD81 and CD82, suggesting their importance in anti-cancer immunity. Overexpression of CD81 and CD82 enhances T cell cytotoxicity against cancer cells, further supporting their role in T cell function. Despite some limitations, these findings shed light on the significant impact of tetraspanins in modulating immune responses, particularly in the context of cancer immunotherapy. Conclusion: We report that CD81 and CD82 serve as specific markers for activated T cells within the TME. CD81 and CD82 are correlated with the activation and regulation of T cells, and they may also mediate the regulation of relevant cytokines. Overall, our findings provide better insights into the molecular mechanisms regulating TILs present in the TME of non-small cell carcinoma and propose CD81 and CD82 as associated markers. These discoveries could serve as a foundation for the development of new immunotherapies targeting the TME. Citation Format: Kwangmin Na, Seul Lee, Dong Kwon Kim, Young Seob Kim, Joon Yeon Hwang, Seong-san Kang, Sujeong Baek, Chai Young Lee, Seung Min Yang, Yu Jin Han, Mi hyun Kim, Heekyung Han, Youngtaek Kim, Jae Hwan Kim, Seunghyun Jeon, Youngseon Byeon, Jii Bum Lee, Sun Min Lim, Min Hee Hong, Kyoung-Ho Pyo, Byoung Chul Cho. CD81 and CD82 in tumor infiltrating lymphocytes within the NSCLC tumor microenvironment play a crucial role in T cell activation and cytokine production [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(6_Suppl):Abstract nr 6805.