Human parainfluenza virus type 3 surface glycoproteins (HPIV3 surface antigens)

Human parainfluenza virus type 3 (HPIV3) surface antigens are primarily composed of two major glycoproteins: the hemagglutinin-neuraminidase (HN) and the fusion (F) protein (Moscona, 2005, Journal of Virology). The HN protein mediates the initial attachment of the virus to sialic acid-containing receptors on the host cell surface and also possesses neuraminidase activity to prevent viral aggregation and facilitate the release of new virions (Henrickson, 2003, Clinical Microbiology Reviews). The F protein is responsible for the subsequent fusion of the viral envelope with the host cell membrane, a process triggered by the binding of HN to its receptor (UniProt P06190). Together, these surface antigens are essential for viral entry, replication, and spread within the respiratory epithelium. In clinical settings, HPIV3 is a leading cause of lower respiratory tract infections, including bronchiolitis and pneumonia, particularly in infants, the elderly, and immunocompromised individuals (PubMed PMID: 12626404). Therapeutic strategies targeting these antigens include small molecule inhibitors, monoclonal antibodies, and sialidases like DAS181, which cleave the host receptors required for HN binding (ClinicalTrials.gov NCT03808922). Because these proteins are exposed on the virion surface, they are also the primary targets for neutralizing antibodies and vaccine development efforts.

Other names

HPIV3 HN and F proteinsParainfluenza 3 surface proteinsHPIV-3 envelope glycoproteinsHemagglutinin-neuraminidase and Fusion proteins

Inhibition of viral attachment to host sialic acid receptors and blockade of viral-host membrane fusion to prevent viral entry and spread.