Human papillomavirus type 16 capsid (HPV16 capsid)

The **Human papillomavirus type 16 capsid** is the icosahedral protein shell that encloses the viral DNA of human papillomavirus type 16 (HPV16), a nonenveloped DNA virus responsible for most cervical and many other anogenital and oropharyngeal cancers[1][2][3][4]. The capsid is primarily composed of 72 pentameric units of the major capsid protein L1, arranged with minor contributions from the L2 protein[1][3][4]. L1 proteins can self-assemble into highly immunogenic virus-like particles (VLPs) that mimic the native viral surface, a property exploited in prophylactic HPV vaccines[4]. The mature capsid is stabilized by inter-pentameric disulfide bonds, notably between Cys175 and Cys428 of L1[1][2][4]. The dynamic nature of the capsid, with flexible linkers and conformational plasticity, is thought to contribute to immune evasion, host cell entry, and environmental stability[3]. Exposed loops on L1 are immunodominant and vary antigenically between HPV types, influencing both immunity and vaccine design. HPV16 capsid is a validated target of neutralizing antibodies elicited by current highly effective HPV vaccines[4].

Other names

HPV16 capsidHPV16 viral capsidHuman papillomavirus 16 capsidHPV16 L1/L2 capsidPapillomavirus 16 capsid

Vaccine-induced neutralizing antibodies bind to exposed surface loops of L1, blocking infection by preventing attachment and entry into host cells[4]. Monoclonal antibodies recognize capsid epitopes, blocking viral entry or marking virions for immune clearance[4].