NASH-HCC对免疫检查点阻断有天然抗药性，但其肿瘤免疫微环境尚不清楚。我们应用成像质谱细胞学的方法，对NASH-HCC、病毒相关HCC（HBV-HCC和HCV-HCC）患者以及健康捐赠者的福尔马林固定和石蜡包埋组织切片进行了空间分辨的单细胞图谱构建。根据35种生物标志物，对超过750,000个独立细胞进行了分13种不同细胞类型的分类，同时考察了关键免疫功能标志物的表达情况。相较于对照组，HCC呈现更高的T细胞、髓源性抑制性细胞（MDSCs）和肿瘤相关巨噬细胞（TAMs）浸润。NASH-HCC中的免疫细胞分布呈空间异质性，富集于相邻正常组织，向肿瘤方向下降。细胞间连接分析揭示了MDSCs和TAMs与CD8+ T细胞在NASH-HCC中的相互作用。特别是，筋骨疲劳的编程细胞死亡1（PD-1+）CD8+ T细胞与程序性细胞死亡配体1（PD-L1+）/可诱导T细胞共刺激分子（ICOS+）MDSCs和TAMs在NASH-HCC中相互连接，而病毒相关的HCC中则没有。相反，在NASH-HCC中，CD4+/CD8+ T细胞中蛋白酶B阳性细胞减少。肿瘤细胞表达PD-L1较低，并且与免疫细胞的连接较少。我们的研究提供了NASH-HCC中单细胞表型和多细胞连接的首个详细空间图谱。我们证明了在NASH-HCC中，MDSCs和TAMs与效应T细胞之间的相互作用是免疫抑制的基础，并有潜力成为治疗的靶点。版权所有 © 2023 作者。由 Wolters Kluwer Health, Inc.出版。

NASH-HCC is inherently resistant to immune checkpoint blockade, but its tumor immune microenvironment is largely unknown.We applied the imaging mass cytometry to construct a spatially resolved single-cell atlas from the formalin-fixed and paraffin-embedded tissue sections from patients with NASH-HCC, virus-HCC (HBV-HCC and HCV-HCC), and healthy donors. Based on 35 biomarkers, over 750,000 individual cells were categorized into 13 distinct cell types, together with the expression of key immune functional markers. Higher infiltration of T cells, myeloid-derived suppressor cell (MDSCs), and tumor-associated macrophages (TAMs) in HCC compared to controls. The distribution of immune cells in NASH-HCC is spatially heterogeneous, enriched at adjacent normal tissues and declined toward tumors. Cell-cell connections analysis revealed the interplay of MDSCs and TAMs with CD8+ T cells in NASH-HCC. In particular, exhausted programmed cell death 1 (PD-1+)CD8+ T cells connected with programmed cell death-ligand 1 (PD-L1+)/inducible T cell costimulator (ICOS+) MDSCs and TAMs in NASH-HCC, but not in viral HCC. In contrast, CD4+/CD8+ T cells with granzyme B positivity were reduced in NASH-HCC. Tumor cells expressed low PD-L1 and showed few connections with immune cells.Our work provides the first detailed spatial map of single-cell phenotypes and multicellular connections in NASH-HCC. We demonstrate that interactions between MDSCs and TAMs with effector T cells underlie immunosuppression in NASH-HCC and are an actionable target.Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc.