Major capsid protein L1 of human papillomavirus (HPV) type 6, 11, 16, and 18 (L1)

The **major capsid protein L1** of human papillomavirus types 6, 11, 16, and 18 is the principal structural protein forming the outer shell (capsid) of HPV virions. L1 self-assembles into 72 pentameric capsomers to construct a robust, immunogenic icosahedral capsid. The L1 protein is highly conserved between HPV types and is the target of current prophylactic HPV vaccines. Vaccines based on recombinant L1 proteins produce virus-like particles (VLPs) that mimic native virions and induce strong, protective antibody responses. Its biological roles include viral genome encapsidation, virion assembly, attachment to host cells, and facilitating the infection process. Disease association includes its essential role in HPV infection, which can lead to benign lesions (warts) and cancers (notably cervical, anal, and oropharyngeal) depending on the HPV type[1][2][3][5][6]. Detection of anti-L1 antibodies serves as an indicator of vaccine-induced or natural immunity. L1 itself is not an enzyme or receptor but is a critical viral antigen and structural protein exploited in vaccine design.

Other names

HPV L1L1 proteinHPV16 L1Major late protein L1

Induces adaptive immune response via neutralizing antibodies (vaccination); Virus-like particle (VLP) formation, which mimics native virus to elicit immunity