Human papillomavirus capsid proteins (L1 and L2) and host cell attachment sites (HPV L1/L2 and attachment sites)

Human papillomavirus (HPV) capsid proteins, specifically the major protein L1 and the minor protein L2, are the structural components of the virus responsible for host cell recognition and entry (Day & Schiller, 2009, PMID: 19641491). The L1 protein forms the icosahedral capsid and mediates the initial attachment to host cell attachment sites, primarily heparan sulfate proteoglycans (HSPGs) on the basement membrane (Giroglou et al., 2001, PMID: 11290771). This binding induces conformational changes that allow the virus to interact with secondary receptors like alpha-6 integrin or tetraspanins for internalization (Abban & Meneses, 2010, PMID: 20610541). These proteins are the primary targets for prophylactic vaccines, such as Gardasil and Cervarix, which utilize L1-based virus-like particles (VLPs) to elicit neutralizing antibodies that block viral attachment (Schiller & Lowy, 2012, PMID: 22543518). Additionally, sulfated polysaccharides like carrageenan are being investigated as topical entry inhibitors that mimic HSPGs to prevent infection (Buck et al., 2006, PMID: 16835380). Targeting these proteins is crucial for preventing HPV-related diseases, including cervical, anal, and oropharyngeal cancers, as well as genital warts.

Other names

HPV L1 proteinHPV L2 proteinHeparan sulfate proteoglycansHSPGsAlpha-6 integrinAnnexin A2CD151Tetraspanins

Prophylactic vaccines induce L1-specific neutralizing antibodies that bind to the viral capsid, sterically hindering its interaction with host cell heparan sulfate proteoglycans (HSPGs) and preventing viral entry (Schiller & Lowy, 2012, PMID: 22543518). Experimental entry inhibitors like carrageenan act as HSPG mimetics, competitively binding to the L1 protein to block attachment to the cell surface (Buck et al., 2006, PMID: 16835380).