The structure of a sialoglycan can be translated into to a biological response when it binds to a specific endogenous lectin. Among endogenous sialic acid-binding lectins in humans are those comprising the 15-member Siglec family, most of which are expressed on overlapping sets of immune cells. Endogenous Siglec ligands are sialoglycolipids (gangliosides) and/or sialoglycoproteins, on cell surfaces or in the extracellular milieu, that bind to and initiate signaling by cell surface Siglecs. In the nervous system, where gangliosides are the predominant sialoglycans, Siglec-4 (myelin-associated glycoprotein) on myelinating cells binds to gangliosides GD1a and GT1b on nerve cell axons to ensure stable and productive axon-myelin interactions. In the immune system, Siglec-7 on natural killer cells binds to gangliosides GD3 and GD2 to inhibit immune signaling. Expression of GD3 and GD2 on cancer cells can lead to tumor immune evasion. Siglec-1 (sialoadhesin, CD169) on macrophages binds to gangliosides on tumors and enveloped viruses. This may enhance antigen presentation in some cases, or increase viral distribution in others. Several other Siglecs bind to gangliosides in vitro, the biological significance of which has yet to be fully established. Gangliosides, which are found on all human cells and tissues in cell-specific distributions, are functional Siglec ligands with varied roles driving Siglec-mediated signaling.

当唾液酸聚糖与特定的内源性凝集素结合时，其结构可以转化为生物反应。人类内源性唾液酸结合凝集素包括由 15 个成员组成的 Siglec 家族，其中大部分在重叠的免疫细胞组上表达。内源性 Siglec 配体是细胞表面或细胞外环境中的唾液酸糖脂（神经节苷脂）和/或唾液酸糖蛋白，它们与细胞表面 Siglec 结合并启动信号传导。在神经系统中，神经节苷脂是主要的唾液酸聚糖，髓鞘形成细胞上的 Siglec-4（髓鞘相关糖蛋白）与神经细胞轴突上的神经节苷脂 GD1a 和 GT1b 结合，以确保轴突-髓鞘相互作用稳定且高效。在免疫系统中，自然杀伤细胞上的 Siglec-7 与神经节苷脂 GD3 和 GD2 结合以抑制免疫信号。GD3和GD2在癌细胞上的表达可导致肿瘤免疫逃逸。巨噬细胞上的 Siglec-1（唾液酸粘附素，CD169）与肿瘤和包膜病毒上的神经节苷脂结合。这可能会在某些情况下增强抗原呈递，或在其他情况下增加病毒分布。其他几种 Siglecs 与神经节苷脂结合体外，其生物学意义尚未完全确定。神经节苷脂以细胞特异性分布存在于所有人类细胞和组织中，是功能性 Siglec 配体，具有驱动 Siglec 介导的信号转导的不同作用。