Human papillomavirus type 18 capsid

The **Human papillomavirus type 18 capsid** is the protein shell of HPV type 18, an oncogenic virus implicated in cervical cancer and other anogenital malignancies[1][3]. The capsid is a stable icosahedral structure, approximately 50–55 nm in diameter, and consists primarily of 72 pentamers of the major capsid protein L1, with a minor component of L2 protein[1][3][2]. The L1 protein can self-assemble into virus-like particles (VLPs) that closely resemble the native virion and are highly immunogenic, which forms the basis for current HPV vaccines[3]. The capsid mediates viral genome packaging, protects viral DNA, enables attachment and entry into host epithelial cells, and orchestrates crucial viral-host interactions necessary for infection and persistence[1][3]. Variation in L1 and L2 structure between HPV types strongly influences antibody recognition and vaccine efficacy, and the L2 protein is increasingly recognized for its role in modulating capsid structure and function[1]. The HPV18 capsid is considered a critical drug and vaccine target for preventing HPV18 infection and associated malignancy.

Other names

HPV18 capsidHPV18 virionHuman papillomavirus type 18 virionHPV-18 capsidHPV18 L1/L2 capsid

Vaccines: Induce neutralizing antibodies against the L1 protein, preventing capsid-mediated attachment and entry into host cells[3]. Antibodies: Bind conformational epitopes on L1, neutralizing the virus by blocking host cell binding or post-entry processes[3][1].