酸化口腔癌之胞外體對免疫 T 細胞的影響

Abstract

口腔癌是全球常見的癌症之一，由於病變部位容易轉移到淋巴結，導致患者 預後不良，五年存活率極低。實驗室先前研究顯示，口腔癌微環境的酸化與腫瘤轉 移密切相關。腫瘤微環境通過不同因子影響腫瘤轉移及免疫系統，其中胞外體作為 生物體內訊息傳遞的工具，參與腫瘤和免疫調節之間的交互作用。然而，目前對酸 化微環境中胞外體對 T 細胞的影響尚未充分了解。 本研究旨在探討酸化微環境中之口腔癌細胞所釋放的胞外體對免疫 T 細胞 的影響。我們使用蛋白質體學和轉錄體學技術分析口腔癌細胞在酸化環境中釋放 的胞外體載物，並將胞外體添加至 T 細胞進行刺激，觀察 T 細胞活性是否受到影 響，並測試 T 細胞的毒殺功能。實驗結果顯示，酸化微環境會導致口腔癌細胞釋 放出含有不同蛋白質和 miRNA 的胞外體，這些胞外體能夠誘導 T 細胞向耗竭狀態 發展，削弱其免疫毒殺功能。這些發現揭示了口腔癌酸化微環境中的胞外體在免疫 調節中的重要作用，並提示酸化微環境可能是口腔癌免疫治療的一大障礙。 這些研究結果有助於更好地理解酸化微環境對口腔癌免疫治療的影響，並 為改進免疫治療策略提供新的思路。我們希望能夠利用這些發現，進一步評估和優 化口腔癌患者的免疫治療方案，最終改善患者的臨床預後。

Oral cancer is a very prevalent cancer worldwide, particularly prone to metastasizing to lymph nodes, and a low five-year survival rate. Previously our laboratory studies have indicated that acidosis of the oral cancer microenvironment is closely associated with tumor metastasis. The tumor microenvironment influences tumor metastasis and the immune system through various factors, among which EVs serve as crucial mediators of intercellular communication, participating in the interplay between tumors and immune regulation. However, the impact of EVs in an acidified microenvironment on T cells in oral cancer remains insufficiently understood. This study aims to investigate the effects of an EVs derived from acidotic oral cancer cells on the cancer cytotoxicity of immune T cell. We employ proteomics and transcriptomics techniques to analyze the contents of EVs released by acidotic oral cancer cells. Furthermore, we stimulate T cells by adding these EVs to the T cell culture and assess their impact using enzyme-linked immunosorbent assay (ELISA) and proteomics. Additionally, microscopy time lapse acquisitions is utilized to evaluate the cytotoxic function of T cells. Experimental results have shown that an acidotic microenvironment induces oral cancer cells to release EVs containing distinct proteins and miRNAs, which can drive T cells towards an exhausted state, thereby impairing their cancer cytotoxic function. These findings reveal the significant role of EVs in one cover immune regulation and suggest that an acidotic microenvironment could be a major barrier to effective immunotherapy for oral cancer. These research outcomes contribute to a better understanding of the impact of an acidified microenvironment on oral cancer immunotherapy and provide new insights for improving immunotherapeutic strategies. We hope to leverage these findings to further evaluate and optimize immunotherapy regimens for oral cancer patients, ultimately enhancing their clinical prognosis.