Viral Interactions with Glycans

The cell surface of mammalian cells is covered with complex glycans or polysaccharides. Several viruses attach to cells via glycans present on the host cell surface. These cell surface glycans such as heparan sulfate proteoglycan enhance the infectivity of host cells. Cell surface glycans also serve as cellular receptors involved in the transmission of endocytosis-inducing signals or in the induction of fusion between viral envelope and cellular membrane for some other viruses. In contrast, viruses can use host cell functions to glycosylate viral proteins, which affects viral glycoprotein stability and function during host cell entry. Glycosylation of viral glycoproteins is also involved in viral antigenicity responsible for immune evasion by viruses. In this review, functions of glycan-mediated interactions between host cells and viruses are discussed.