T 细胞介导的反应的效力是免疫疗法治疗恶性肿瘤有效性的决定因素；然而，由于广泛的免疫抑制微环境，T细胞疗法在肝细胞癌（HCC）中的临床疗效受到限制。在此，我们旨在研究促进HCC免疫逃逸的关键基因，并提出重塑HCC免疫逃逸的新治疗策略。 HCC微环境。通过体内全基因组规则间隔短回文重复序列（CRISPR）筛选文库来鉴定与免疫耐受相关的关键基因。采用单细胞RNA-seq（scRNA-seq）、流式细胞术、HCC小鼠模型、染色质免疫沉淀和免疫共沉淀等方法探讨腺苷酸环化酶7（ADCY7）在HCC免疫监测中的功能和机制。体内CRISPR筛选鉴定出一种新型免疫调节剂——ADCY7。跨膜蛋白 ADCY7 通过小窝介导的内吞作用进行亚细胞易位，然后在富含亮氨酸重复序列的蛋白 59 (LRRC59) 和核转运蛋白亚基 β 1 (KPNB1) 的帮助下易位到细胞核。在细胞核中，它作为 CCAAT/增强子结合蛋白 α (CEBPA) 的转录辅助因子，诱导 CCL5 转录，从而增加 CD8 T 细胞浸润，抑制 HCC 进展。此外，ADCY7可以作为外泌体分泌并进入邻近的肿瘤细胞以促进CCL5诱导。 ADCY7水平高的外泌体促进CD8 T细胞的肿瘤内浸润并抑制HCC肿瘤生长。我们描述了ADCY7的非常规功能和亚细胞位置，强调了它在HCC T细胞介导的免疫中的关键作用及其作为有希望的治疗靶点的潜力。 © 作者（或其雇主）2024。根据 CC BY-NC 允许重复使用。禁止商业再利用。请参阅权利和权限。英国医学杂志出版。

The potency of T cell-mediated responses is a determinant of immunotherapy effectiveness in treating malignancies; however, the clinical efficacy of T-cell therapies has been limited in hepatocellular carcinoma (HCC) owing to the extensive immunosuppressive microenvironment.Here, we aimed to investigate the key genes contributing to immune escape in HCC and raise a new therapeutic strategy for remoulding the HCC microenvironment.The genome-wide in vivo clustered regularly interspaced short palindromic repeats (CRISPR) screen library was conducted to identify the key genes associated with immune tolerance. Single-cell RNA-seq (scRNA-seq), flow cytometry, HCC mouse models, chromatin immunoprecipitation and coimmunoprecipitation were used to explore the function and mechanism of adenylate cyclase 7 (ADCY7) in HCC immune surveillance.Here, a genome-wide in vivo CRISPR screen identified a novel immune modulator-ADCY7. The transmembrane protein ADCY7 undergoes subcellular translocation via caveolae-mediated endocytosis and then translocates to the nucleus with the help of leucine-rich repeat-containing protein 59 (LRRC59) and karyopherin subunit beta 1 (KPNB1). In the nucleus, it functions as a transcription cofactor of CCAAT/enhancer binding protein alpha (CEBPA) to induce CCL5 transcription, thereby increasing CD8+ T cell infiltration to restrain HCC progression. Furthermore, ADCY7 can be secreted as exosomes and enter neighbouring tumour cells to promote CCL5 induction. Exosomes with high ADCY7 levels promote intratumoural infiltration of CD8+ T cells and suppress HCC tumour growth.We delineate the unconventional function and subcellular location of ADCY7, highlighting its pivotal role in T cell-mediated immunity in HCC and its potential as a promising treatment target.© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.