Human papillomavirus capsid proteins L1 and L2 (HPV L1/L2)

The Human papillomavirus (HPV) capsid proteins, L1 and L2, are the primary structural components responsible for the virus's ability to attach to and enter host epithelial cells (Buck et al., 2013). The major capsid protein, L1, forms the outer icosahedral shell and mediates the initial binding to heparan sulfate proteoglycans (HSPGs) on the basement membrane or cell surface (Day & Schiller, 2009). Following this attachment, the minor capsid protein, L2, undergoes conformational changes that facilitate the interaction with secondary receptors and subsequent endocytosis (Schiller & Lowy, 2012). These proteins are the fundamental targets for prophylactic HPV vaccines, which utilize recombinant L1 virus-like particles (VLPs) to stimulate the production of neutralizing antibodies (Harper & DeMars, 2017). By binding to the L1 protein, these antibodies effectively block the virus from adhering to host cells, preventing the establishment of infection. Persistent infection with high-risk HPV types is a leading cause of cervical, anal, and oropharyngeal cancers, making these capsid proteins critical targets for cancer prevention (Doorbar et al., 2012). Additionally, research into entry inhibitors like carrageenan focuses on disrupting the L1-host interaction as a topical microbicide strategy (Buck et al., 2006).

Other names

HPV L1 proteinHPV L2 proteinMajor capsid protein L1Minor capsid protein L2HPV capsidL1/L2 complex

Neutralization of viral particles by antibodies to prevent host cell attachment and entry; competitive inhibition of binding to host cell receptors by glycan mimics.