头颈部鳞状细胞癌（HNSCC）是常见的位于头颈部的恶性肿瘤，5年生存率较低。尽管免疫疗法取得了显著进展，但在HNSCC治疗中的疗效仍然不尽如人意。杀手细胞凝集素样受体K1（KLRK1）是一种高表达于免疫细胞的标志物，能够结合癌细胞表达的配体以发挥其抗肿瘤效应。然而，KLRK1在HNSCC中的作用尚未得到广泛研究。本研究旨在探讨KLRK1在HNSCC免疫浸润和预后相关性中的参与。我们分析了癌基因组图谱数据库中KLRK1的表达数据，并研究了KLRK1与免疫细胞浸润的关系。最后，我们分析了KLRK1及其配体的表达与HNSCC患者预后的关联。我们发现KLRK1在HNSCC中高表达，并与较好的预后相关。KLRK1的表达与年龄、组织学分级、HPV感染、pT、pN、pTNM分期、原发部位和生存状态相关。高表达的KLRK1与较高水平的免疫细胞浸润，特别是CD4/8(+) T淋巴细胞，相关联。在KLRK1的配体中，UL16结合蛋白（ULBP）1-3表达较高，与死亡风险增加相关。值得注意的是，KLRK1的表达与ULBP1-3呈负相关。扁桃体癌中ULBP2/3表达水平高的患者预后较差（P < .01），而ULBP1的表达水平对扁桃体癌预后没有显著影响（P = .770）。ULBP1/3的表达水平与喉癌患者预后较差相关（P < .05），而ULBP2的表达水平与总体生存无显著相关性（P = .269）。我们的研究揭示了KLRK1在HNSCC中高表达，并与较好的预后和免疫浸润相关。高表达KLRK1配体的患者预后较差，可能是由于更多可溶性配体的表达引起的。版权所有 © 2023 作者。 Wolters Kluwer Health, Inc.发表。

Head and neck squamous cell carcinoma (HNSCC) is a malignancy commonly found in the head and neck region, with a low 5-year survival rate. Although immunotherapy has made significant progress, its efficacy in HNSCC treatment remains unsatisfactory. Killer cell lectin-like receptor K1 (KLRK1), a marker highly expressed in immune cells, can bind to its ligands expressed by cancer cells to exert its antitumor effect. However, the role of KLRK1 in HNSCC has yet to be studied extensively. This study aimed to explore the involvement of KLRK1 in immune infiltration of HNSCC and its correlation with prognosis. We analyzed KLRK1 expression data from the Cancer Genome Atlas database. The relationship between KLRK1 and immune cell infiltration has also been investigated. Finally, we analyzed the association between the expression of KLRK1 and its ligands and the prognosis of patients with HNSCC. We found that KLRK1 was highly expressed in HNSCC and correlated with better prognosis. KLRK1 expression was correlated with age, histological grade, HPV infection, pT, pN, pTNM stage, primary site, and survival status. High expression levels of KLRK1 have been linked to high levels of immune cell infiltration, particularly CD4/8 (+) T lymphocytes. Among the ligands of KLRK1, UL16 binding protein (ULBP) 1-3 showed high expression, which was associated with an increased risk of death. Notably, the expression of KLRK1 was negatively correlated with ULBP1-3. Patients with high levels of ULBP2/3 expression in tonsil carcinoma had poorer prognosis than those with low levels (P < .01), whereas ULBP1 expression levels had no significant effect on tonsil carcinoma prognosis (P = .770). The expression levels of ULBP1/3 were correlated with worse prognosis in patients with laryngeal cancer (P < .05), whereas there was no significant correlation between ULBP2 expression levels and overall survival (P = .269). Our study revealed that KLRK1 is highly expressed in HNSCC and is associated with a better prognosis and immune infiltration. Patients with high expression of KLRK1 ligands exhibited worse prognoses, possibly because of the expression of more soluble ligands.Copyright © 2023 the Author(s). Published by Wolters Kluwer Health, Inc.