Cell-surface sialic acid-containing glycoconjugates (Sialoglycoconjugates)

Cell-surface sialic acid-containing glycoconjugates, or sialoglycans, are complex molecules consisting of carbohydrates linked to proteins or lipids, characterized by terminal sialic acid residues. These nine-carbon acidic sugars are ubiquitous on the mammalian glycocalyx and play a fundamental role in mediating cell-cell interactions and maintaining the negative charge of the cell surface (Varki, 2008, Nature). They function as critical checkpoints in the immune system by interacting with sialic acid-binding immunoglobulin-type lectins (Siglecs), which typically transmit inhibitory signals to immune cells like Natural Killer (NK) cells and macrophages (Crocker et al., 2007, Nature Reviews Immunology). In oncology, many tumors exhibit hypersialylation, creating a glycan-based 'shield' that allows them to evade immune detection and promote metastasis (Pearce & Läubli, 2016, Glycobiology). Additionally, these glycoconjugates serve as essential attachment points for numerous pathogens, including influenza viruses and certain bacteria, which utilize hemagglutinins to bind sialic acids for host cell entry (Matrosovich et al., 2013, Journal of Virology). Therapeutic strategies targeting these molecules include neuraminidase inhibitors that block viral spread and novel sialidase-based biologics, such as E-602, designed to desialylate cancer cells and restore anti-tumor immunity (Gray et al., 2020, Nature Chemical Biology).

Other names

SialoglycansSialylated glycansSialoglycoproteinsSialoglycolipidsCell-surface sialosides

Inhibition of viral neuraminidase to prevent the cleavage of sialic acid and viral release; enzymatic desialylation of the tumor microenvironment to enhance immune cell activation; competitive blocking of sialic acid-binding sites by lectins or antibodies.