Department of Otorhinolaryngology, Head and Neck Surgery, University Medical Center Göttingen, Göttingen, Germany.
Institute of Biochemistry I, Faculty of Medicine, Goethe-University Frankfurt, Frankfurt am Main, Germany.
Front Immunol. 2024 Jan 23;14:1240394. doi: 10.3389/fimmu.2023.1240394. eCollection 2023.
Interactions between tumor cells and cells in the microenvironment contribute to tumor development and metastasis. The spatial arrangement of individual cells in relation to each other influences the likelihood of whether and how these cells interact with each other.
This study investigated the effect of spatial distribution on the function of leukocyte subsets in the microenvironment of human head and neck squamous cell carcinoma (HNSCC) using multiplex immunohistochemistry (IHC). Leukocyte subsets were further classified based on analysis of two previously published HNSCC single-cell RNA datasets and flow cytometry (FC).
IHC revealed distinct distribution patterns of leukocytes differentiated by CD68 and CD163. While CD68hiCD163 and CD68CD163 cells accumulated near tumor sites, CD68CD163 cells were more evenly distributed in the tumor stroma. PD-L1 and PD-1 cells accumulated predominantly around tumor sites. High cell density of PD-L1 CD68CD163 cells or PD-1 T cells near the tumor site correlated with improved survival. FC and single cell RNA revealed high variability within the CD68/CD163 subsets. CD68CD163 and CD68CD163 cells were predominantly macrophages (MΦ), whereas CD68CD163 cells appeared to be predominantly dendritic cells (DCs). Differentiation based on CD64, CD80, CD163, and CD206 revealed that TAM in HNSCC occupy a broad spectrum within the classical M1/M2 polarization. Notably, the MΦ subsets expressed predominantly CD206 and little CD80. The opposite was observed in the DC subsets.
The distribution patterns and their distinct interactions via the PD-L1/PD-1 pathway suggest divergent roles of CD68/CD163 subsets in the HNSCC microenvironment. PD-L1/PD-1 interactions appear to occur primarily between specific cell types close to the tumor site. Whether PD-L1/PD-1 interactions have a positive or negative impact on patient survival appears to depend on both the spatial localization and the entity of the interacting cells. Co-expression of other markers, particularly CD80 and CD206, supports the hypothesis that CD68/CD163 IHC subsets have distinct functions. These results highlight the association between spatial leukocyte distribution patterns and the clinical presentation of HNSCC.
肿瘤细胞与微环境中的细胞之间的相互作用促进了肿瘤的发展和转移。单个细胞之间的空间排列方式影响了它们相互作用的可能性和方式。
本研究使用多重免疫组化（IHC）技术研究了空间分布对人类头颈部鳞状细胞癌（HNSCC）微环境中白细胞亚群功能的影响。根据两个先前发表的 HNSCC 单细胞 RNA 数据集和流式细胞术（FC）的分析，进一步对白细胞亚群进行分类。
IHC 显示出由 CD68 和 CD163 区分的白细胞的不同分布模式。虽然 CD68hiCD163 和 CD68CD163 细胞聚集在肿瘤部位附近，但 CD68CD163 细胞在肿瘤基质中分布更为均匀。PD-L1 和 PD-1 细胞主要聚集在肿瘤部位周围。肿瘤部位附近 PD-L1 CD68CD163 细胞或 PD-1 T 细胞的高细胞密度与改善的生存相关。FC 和单细胞 RNA 揭示了 CD68/CD163 亚群内的高度可变性。CD68CD163 和 CD68CD163 细胞主要是巨噬细胞（MΦ），而 CD68CD163 细胞似乎主要是树突状细胞（DC）。基于 CD64、CD80、CD163 和 CD206 的分化表明，HNSCC 中的 TAM 占据了经典 M1/M2 极化的广泛谱。值得注意的是，MΦ 亚群主要表达 CD206，很少表达 CD80。在 DC 亚群中则观察到相反的情况。
分布模式及其通过 PD-L1/PD-1 途径的独特相互作用表明，CD68/CD163 亚群在 HNSCC 微环境中具有不同的作用。PD-L1/PD-1 相互作用似乎主要发生在靠近肿瘤部位的特定细胞类型之间。PD-L1/PD-1 相互作用对患者生存的影响是积极的还是消极的，似乎取决于相互作用细胞的空间定位和实体。其他标记物（特别是 CD80 和 CD206）的共表达支持 CD68/CD163 IHC 亚群具有不同功能的假设。这些结果强调了白细胞空间分布模式与 HNSCC 临床表现之间的关联。
