Sialic acid (Sia)

Sialic acids are a family of nine-carbon acidic monosaccharides typically found at the terminal positions of glycans on the cell surface and secreted glycoproteins [1]. They play a critical role in various biological processes, including cell-cell adhesion, signal transduction, and the regulation of the immune system by acting as "self" markers that prevent autoimmune responses [2]. In the context of infectious diseases, sialic acid residues on host cells serve as essential receptors for the attachment and entry of numerous pathogens, most notably the influenza and parainfluenza viruses [3]. Conversely, virion-associated sialic acids can lead to viral aggregation, which is why viruses like influenza carry neuraminidase enzymes to cleave these residues during budding to ensure efficient release of progeny [4]. Therapeutic strategies targeting these residues include the use of recombinant sialidases, such as DAS181 (Fludase), which enzymatically remove sialic acids from the respiratory epithelium to block viral infection [5]. Additionally, hypersialylation of cancer cells is associated with tumor progression and immune evasion via interaction with Siglec receptors, making these residues a target for novel oncology treatments [6].

Other names

N-acetylneuraminic acidNeu5AcNANANeuraminic acidSialic acid residuesPoly-sialic acid

Enzymatic cleavage of terminal sialic acid residues from host cell surface glycoconjugates to prevent viral attachment and entry.