唾液酸结合免疫球蛋白样凝集素15(sialic acid-binding immunoglobulin-like lectin 15,Siglec-15)是唾液酸结合免疫球蛋白样凝集素(sialic acid-binding immunoglobulin-type lectins, Siglecs)的成员之一,在 Siglecs 受体超家族中属于免疫抑制性受体,近年来其在肿瘤免疫中的作用备受关注。Siglec-15通过调节免疫微环境,影响肿瘤的进展和预后,成为肿瘤免疫治疗的新靶点。胃肠道肿瘤的免疫治疗目前已成为继手术、化疗、放疗和靶向治疗之后的又一重要治疗手段。程序性细胞死亡蛋白1(programmed cell death protein 1, PD-1)/程序性死亡配体1(programmed death-ligand 1, PD-L1)抑制剂和细胞毒性T淋巴细胞相关蛋白4(cytotoxic T-lymphocyte-associated protein 4, CTLA-4)抑制剂在部分患者中展现疗效,但仍面临耐药性和生物标志物筛选等挑战。本综述旨在系统回顾Siglec-15与胃肠道肿瘤免疫关系的研究进展, 涵盖其生物学特性、在胃肠道肿瘤中的表达及免疫调节机制和未来基于Siglec-15的治疗策略, 以期为胃肠道肿瘤的免疫治疗提供新的思路和策略。

Sialic acid-binding immunoglobulin-like lectin 15 (Siglec-15) is a member of the Siglec family and functions as an immunosuppressive receptor within the Siglecs superfamily. In recent years, its role in tumor immunity has attracted increasing attention. By modulating the immune microenvironment, Siglec-15 contributes to tumor progression and prognosis,emerging as a novel target for cancer immunotherapy. Immunotherapy for gastrointestinal tumors has become a pivotal treatment approach following surgery, chemotherapy, radiotherapy, and targeted therapy. While PD-1/PD-L1 and CTLA-4 inhibitors have shown efficacy in some patients, challenges such as drug resistance and biomarker identification remain. This review systematically summarizes recent advances in understanding the relationship between Siglec-15 and gastrointestinal tumor immunity, covering its biological characteristics, expression patterns in gastrointestinal cancers, immunomodulatory mechanisms, and potential therapeutic strategies targeting Siglec-15. These findings may provide new insights and approaches for immunotherapy in gastrointestinal malignancies.