肝星状细胞（HSC）通过调节多种因素促进肝细胞癌（HCC）的进展。然而，HSC 的整个免疫调节功能仍然不清楚。在这里，我们的目的是研究HSC是否在瘤周区域赋予CX3CR1巨噬细胞促肿瘤特性。在HCC患者的单细胞RNA测序分析中，在瘤周区域特异性表达Arg1和Cx3cr1的巨噬细胞亚群，并且高度富集与视黄醇代谢相关的基因。流式细胞术分析显示，HCC 邻近区域中 CD14 CD11b HLA-DR-巨噬细胞与 CX3CR1 的频率显着增加，其中表达 α-SMA 的激活 HSC (aHSC) 显示 CX3CL1 共定位表达。因此，在荷瘤小鼠中，邻近 HCC 内的 aHSC 中 Cx3cl1 mRNA 表达显着增加，其中主要观察到 CX3CR1 Ly6C 巨噬细胞的浸润，同时 CD8 T 细胞减少。在骨髓细胞的过继转移和体外共培养中，我们证明CX3CR1 Ly6C巨噬细胞通过与邻近HCC中富含类维生素A的aHSC相互作用来迁移并高表达精氨酸酶1。直接处理类维生素A或与储存视黄醇的小鼠aHSC或人LX-2细胞共培养可显着增加CX3CR1 Ly6C巨噬细胞和人血液CD14细胞中精氨酸酶1的表达，从而抑制CD8 T细胞增殖。此外，骨髓细胞中CX3CR1的遗传缺陷或视黄醇代谢的药物抑制显着减弱了HCC的发展。我们发现CX3CR1 Ly6C巨噬细胞在瘤周区域迁移并与aHSC相互作用，其中类维生素A诱导CX3CR1 Ly6C巨噬细胞中精氨酸酶1的表达，随后剥夺CD8精氨酸 T 细胞与促进 HCC。版权所有 © 2024 美国肝病研究协会。

Hepatic stellate cells (HSCs) contribute to hepatocellular carcinoma (HCC) progression by regulating multiple factors. However, the entire immunoregulatory functions of HSCs are still obscure. Here, we aim to investigate whether HSCs impose CX3CR1+ macrophages to pro-tumorigenic properties in the peritumoral area.In single cell RNA-sequencing analysis of HCC patients, a subpopulation of macrophages specifically expressed Arg1 and Cx3cr1 in the peritumoral area, and were highly enriched with retinol metabolism-related genes. Flow cytometry analysis showed significantly increased frequencies of CD14+CD11b+HLA-DR‒ macrophages with CX3CR1 in the HCC adjacent region where α-SMA-expressing activated HSCs (aHSCs) showed co-localized expression of CX3CL1. Accordingly, in tumor-bearing mice, Cx3cl1 mRNA expression was notably increased in aHSCs within the adjacent HCC, where infiltration of CX3CR1+Ly6C+ macrophages was mostly observed with decreased CD8+ T cells. In adoptive transfer and in vitro co-culture of myeloid cells, we demonstrated that CX3CR1+Ly6C+ macrophages migrated and highly expressed arginase-1 by interacting with retinoid-enriched aHSCs in the adjacent HCC. Direct treatment of retinoids or co-culturing with retinol-storing mouse aHSCs or human LX-2 cells significantly increased arginase-1 expression in CX3CR1+Ly6C+ macrophages and human blood CD14+ cells, leading to the suppression of CD8+ T cell proliferation. Moreover, genetic deficiency of CX3CR1 in myeloid cells or pharmacological inhibition of retinol metabolism remarkably attenuated HCC development.We showed that CX3CR1+Ly6C+ macrophages migrate and interact with aHSCs in the peritumoral region where retinoids induce arginase-1 expression in CX3CR1+Ly6C+ macrophages, subsequently depriving CD8+ T cells of arginine and promoting HCC.Copyright © 2024 American Association for the Study of Liver Diseases.