分析表現CXCR2之基因改造CD8 T細胞在自發性肝癌小鼠模式中抑制腫瘤之能力

Abstract

肝細胞癌為一種原發性肝癌，其占比高達所有原發性肝癌之90%。治療方式常見的有手術切除、放射治療，或是藥物治療如酪胺酸酶抑制劑(TKI)和免疫製劑如免疫檢查點抑制劑(ICI)等。而近年來細胞治療逐漸盛行，尤其是CAR-T在治療血液腫瘤有所成果。然而在固態腫瘤上，細胞治療仍然無法有顯著治療效果，原因與腫瘤形成之免疫微環境有關。固態腫瘤如肝癌在細胞治療下無法達到有效的治療效果。原因可能與抑制性免疫微環境及T細胞排除現象有關。為了跨越此阻礙，我們設計能過量表現趨化因子接收器的T細胞。過去的研究證實趨化因子配體可以吸引有相對應接收器之T細胞進而增強T細胞浸潤。所以我們先分析自發性肝癌模型中的趨化因子表現概況，並聚焦於CXCR2。我們發現在HCC中存在大量CXCR2⁺細胞，且腫瘤細胞表現CXCR2相關的配體。因此我們選擇CXCR2作為T細胞基因改造的候選趨化因子受體。我們建立了轉導流程以產生基因改造細胞。不幸的是，我們以逆轉錄病毒或慢病毒載體轉導的CXCR2過度表現T細胞在體外或體內無法長時間維持。導致CXCR2過度表現細胞存活短暫的原因尚不明確，因此我們呈現了解決此問題的策略，以及在我們自發性 HCC 小鼠模型中進行體內移植性細胞治療的初步實驗結果。

Hepatocellular carcinoma (HCC) is a primary liver cancer with high prevalence and accounts for approximately 90% of all primary liver cancer. Common treatments include physical interventions such as surgical resection and radiotherapy, and pharmacological therapies including tyrosine kinase inhibitors (TKIs) and immune checkpoint inhibitors (ICIs). In recent years, cellular therapies such as CAR-T and TCR-T have become increasingly prevalent in cancer treatment, especially the use of CAR-T cells in the treatment of hematologic malignancies. However, cell therapy has shown limited clinical efficacy in solid tumors due to the immunosuppressive tumor microenvironment (TME) and T cell exclusion. To overcome this barrier, we designed engineered CD8+ T cells expressing specific chemokine receptors. Previous research has shown that chemokine ligands in the TME can attract T cells expressing the corresponding chemokine receptors, thereby enhancing T cell infiltration. Following that we first analyzed the chemokine profile inside our spontaneous HCC model, focusing on CXCR2. We found many CXCR2⁺ cells in HCC, and CXCR2-related ligands were expressed by tumor cells. Therefore, we selected CXCR2 as our chemokine receptor candidate for T cell engineering. We established a transduction protocol for generating engineered cells using retroviral or lentiviral vectors. Unfortunately, our initial attempt to generate retroviral or lentiviral vector-transduced CXCR2-overexpressing T cells could not make them sustained in vitro and in vivo. The reason causing the short-living period of our retroviral transduced CXCR2-overexpression cells remained unclear. We thus presented the strategies we had adopted to troubleshoot this issue, and the results of our pilot experiment for in vivo adoptive cell therapy in our spontaneous HCC mouse model.