Major capsid protein L1 (Human papillomavirus 31) (HPV31 L1)

The Human Papillomavirus (HPV) type 31 L1 major capsid protein is the primary structural component of the HPV31 virion, a high-risk genotype associated with cervical, anogenital, and oropharyngeal cancers. This protein self-assembles into icosahedral capsids composed of 72 pentamers, which are essential for protecting the viral genome and mediating host cell entry. Biologically, the L1 protein facilitates the initial attachment of the virus to heparan sulfate proteoglycans on the surface of host basal keratinocytes. This interaction triggers conformational changes that allow the virus to be internalized via endocytosis. Due to its high immunogenicity and surface exposure, the L1 protein is the primary antigen used in prophylactic HPV vaccines, such as the nonavalent Gardasil 9. These vaccines utilize recombinant L1-based virus-like particles (VLPs) to induce the production of neutralizing antibodies that target surface-exposed hypervariable loops. These antibodies effectively block viral attachment and entry, providing robust protection against persistent infection. By preventing infection, these vaccines significantly reduce the risk of developing HPV31-related precancerous lesions and malignancies.

Other names

L1 proteinMajor capsid protein L1HPV31 L1VL1_HPV31Late protein L1

Induction of neutralizing antibodies that bind to surface-exposed L1 loops, blocking viral attachment to heparan sulfate proteoglycans and preventing host cell entry.