Sialic acid sugar-carrying glycans, sialoglycans, are aberrantly expressed on many tumor cells and have emerged as potent regulatory molecules involved in creating a tumor-supportive microenvironment. Sialoglycans can be recognized by sialic acid-binding immunoglobulin-like lectins (Siglecs), a family of immunomodulatory receptors. Most mammalian Siglecs transmit inhibitory signals comparable with the immune checkpoint inhibitor programmed death protein 1 (PD-1), but some are activating. Recent studies have shown that tumor cells can exploit sialoglycan–Siglec interactions to modulate immune cell function, contributing to an immunosuppressive tumor microenvironment (TME). Interference with sialoglycan synthesis or sialoglycan–Siglec interactions might improve antitumor immunity. Many questions regarding specificity, signaling, and regulatory function of sialoglycan–Siglec interactions remain. We posit that sialoglycans and Siglecs present as potential glyco-immune ‘checkpoints’ for cancer immunotherapy.

携带唾液酸糖的聚糖，唾液聚糖在许多肿瘤细胞上异常表达，并且已经作为参与创建支持肿瘤的微环境的有效调节分子而出现。唾液酸聚糖可以被唾液酸结合的免疫球蛋白样凝集素（Siglecs）（一种免疫调节受体家族）识别。大多数哺乳动物的Siglecs传递的抑制信号与免疫检查点抑制剂编程的死亡蛋白1（PD-1）相当，但其中一些正在激活。最近的研究表明，肿瘤细胞可以利用唾液酸聚糖-Siglec相互作用来调节免疫细胞功能，从而有助于免疫抑制性肿瘤微环境（TME）。干扰唾液酸聚糖合成或唾液酸聚糖-Siglec相互作用可能会提高抗肿瘤免疫力。有关特异性，信号传递，和唾液酸聚糖-Siglec相互作用的调节功能仍然存在。我们假设唾液聚糖和Siglecs作为癌症免疫治疗的潜在糖免疫“检查点”存在。