Cell-surface sialoglycans (Sialoglycans)

Cell-surface sialoglycans are complex carbohydrate structures terminated with sialic acid residues that decorate the surface of all mammalian cells, particularly immune cells and their targets. They function as critical components of the glyco-immune checkpoint by interacting with Sialic acid-binding immunoglobulin-type lectins (Siglecs) to modulate immune cell activity and maintain self-tolerance (Varki et al., 2017, Essentials of Glycobiology). In the context of oncology, many tumors exhibit hypersialylation, which serves as a potent immune evasion mechanism by triggering inhibitory Siglec signaling on natural killer (NK) cells, macrophages, and T cells, effectively creating a "don't eat me" or "don't kill me" signal (Duan and Paulson, 2020, Annual Review of Immunology). Therapeutic interventions, such as the sialidase fusion protein E-602, aim to enzymatically remove these sialic acids from the cell surface to "unmask" the tumor and restore anti-tumor immune recognition (Gray et al., 2020, Nature Chemical Biology). This approach represents a novel frontier in immunotherapy, targeting the glycome to overcome resistance to traditional protein-based checkpoint inhibitors.

Other names

Sialic acid-containing glycansSiglec ligandsSialylated glycansTumor-associated sialoglycansGlyco-immune checkpoints

Enzymatic desialylation of the cell surface to remove immunosuppressive sialic acids and enhance anti-tumor immune activity by disrupting the Siglec-sialoglycan signaling axis.