Department of Otorhinolaryngology Head and Neck Surgery, The Third Affiliated Hospital of Soochow University, Changzhou, Jiangsu, China.
Department of Tumor Biological Treatment, The Third Affiliated Hospital of Soochow University, Changzhou, 213003, Jiangsu, China.
Cancer Immunol Immunother. 2024 Aug 6;73(10):207. doi: 10.1007/s00262-024-03791-6.
HHLA2 (human endogenous retrovirus-H long terminal repeat-associating protein 2) represents a recently identified member of the B7 immune checkpoint family, characterized by limited expression in normal tissues but notable overexpression in various cancer types. Nevertheless, the precise function and interaction with immune cells remain poorly understood, particularly in laryngeal squamous cell carcinoma (LSCC). This investigation endeavored to elucidate the biological significance of HHLA2 within the tumor microenvironment of human LSCC tissues and delineate the clinical relevance and functional roles of HHLA2 in LSCC pathogenesis.
Through multiplexed immunohistochemistry analyses conducted on tissue microarrays sourced from LSCC patients (n = 72), the analysis was executed to assess the expression levels of HHLA2, density and spatial patterns of CD68HLA-DRCD163 (M1 macrophages), CTLA-4CD4FoxP3 (CTLA-4Treg cells), CTLA-4CD4FoxP3 (CTLA-4Tcon cells), exhausted CD8T cells, and terminally exhausted CD8T cells in LSCC tissues. Survival analysis was conducted to evaluate the prognostic significance of HHLA2 and these immune checkpoints or immune cell populations, employing COX regression analysis to identify independent prognostic factors.
Kaplan-Meier (K-M) survival curves revealed a significant association between HHLA2 expression and overall survival (OS) in LSCC. Elevated levels of HHLA2 were linked to reduced patient survival, indicating its potential as a prognostic marker (HR: 3.230, 95%CI 0.9205-11.34, P = 0.0067). Notably, increased infiltration of CD68 cells (total macrophages), STINGCD68HLA-DRCD163 (STINGM1 macrophages), CTLA-4CD4FoxP3, CTLA-4CD4FoxP3, PD-1LAG-3CD8T cells, and PD-1LAG-3TIM-3CD8T cells strongly linked to poorer survival outcomes (P < 0.05). A discernible trend was observed between the levels of these immune cell populations, STINGCD68 (STING total macrophages), CD68HLA-DRCD163, STINGCD68CD163HLA-DR (STINGM2 macrophages), PD-1LAG-3CD8T cells, PD-1TIM-3CD8T cells, and PD-1LAG-3TIM-3CD8T cells and prognosis. Importantly, multivariate COX analysis identified HHLA2 as an independent predictive factor for OS in LSCC patients (HR = 3.86, 95% CI 1.08-13.80, P = 0.038). This underscored the potential of HHLA2 as a critical marker for predicting patient outcomes in LSCC.
HHLA2 emerged as a detrimental prognostic biomarker for assessing OS in LSCC patients. Relative to other immune checkpoints, HHLA2 exhibited heightened predictive efficacy for the prognosis of LSCC patients.
HHLA2（人类内源性逆转录病毒-H 长末端重复相关蛋白 2）是最近发现的 B7 免疫检查点家族的成员之一，其特点是在正常组织中表达有限，但在各种癌症类型中明显过表达。然而，其确切功能和与免疫细胞的相互作用仍知之甚少，特别是在喉鳞状细胞癌（LSCC）中。本研究旨在阐明 HHLA2 在人 LSCC 组织肿瘤微环境中的生物学意义，并阐明 HHLA2 在 LSCC 发病机制中的临床相关性和功能作用。
通过对 LSCC 患者（n=72）的组织微阵列进行多重免疫组化分析，评估 HHLA2、CD68+HLA-DR+CD163（M1 巨噬细胞）、CTLA-4+CD4+FoxP3（CTLA-4Treg 细胞）、CTLA-4+CD4+FoxP3（CTLA-4Tcon 细胞）、耗竭 CD8+T 细胞和终末耗竭 CD8+T 细胞在 LSCC 组织中的表达水平。通过 COX 回归分析识别独立的预后因素，进行生存分析以评估 HHLA2 和这些免疫检查点或免疫细胞群体的预后意义。
Kaplan-Meier（K-M）生存曲线显示 HHLA2 表达与 LSCC 患者的总生存期（OS）显著相关。HHLA2 水平升高与患者生存时间缩短相关，表明其可能是一种预后标志物（HR：3.230，95%CI 0.9205-11.34，P=0.0067）。值得注意的是，CD68 细胞（总巨噬细胞）、STING+CD68+HLA-DR+CD163（STINGM1 巨噬细胞）、CTLA-4+CD4+FoxP3、CTLA-4+CD4+FoxP3、PD-1+LAG-3+CD8+T 细胞和 PD-1+LAG-3+TIM-3+CD8+T 细胞的浸润增加与较差的生存结局强烈相关（P<0.05）。这些免疫细胞群体之间存在明显的趋势，包括 STING+CD68（STING 总巨噬细胞）、CD68+HLA-DR+CD163、STING+CD68+CD163+HLA-DR（STINGM2 巨噬细胞）、PD-1+LAG-3+CD8+T 细胞、PD-1+TIM-3+CD8+T 细胞和 PD-1+LAG-3+TIM-3+CD8+T 细胞与预后相关。重要的是，多变量 COX 分析确定 HHLA2 是 LSCC 患者 OS 的独立预测因子（HR=3.86，95%CI 1.08-13.80，P=0.038）。这突显了 HHLA2 作为预测 LSCC 患者预后的关键标志物的潜力。
HHLA2 是评估 LSCC 患者 OS 的有害预后生物标志物。与其他免疫检查点相比，HHLA2 对 LSCC 患者的预后具有更高的预测效能。
