Major capsid protein L1 of human papillomavirus type 16 and type 18 (L1)

The major capsid protein L1 is the principal structural component in the icosahedral shell of human papillomavirus (HPV) virions, including types 16 and 18, which are strongly associated with cervical and other anogenital and head/neck cancers[1][4][5]. L1 spontaneously self-assembles into pentameric capsomers and subsequently into virus-like particles (VLPs) in vitro, a property exploited in HPV vaccines such as Gardasil and Cervarix[2][4][7]. The L1 protein mediates critical virus-host interactions, including initial attachment to host cell surface receptors and encapsidation of the viral DNA[1][2][3][5]. Sequence variability in its surface loops determines type specificity and the effectiveness of neutralizing antibodies, making L1 the prime antigen for prophylactic vaccination[2][4][7]. The protein itself does not possess enzymatic or signaling activity but serves as a crucial target for immune interventions to prevent infection and associated cancer development.

Other names

HPV16 L1 proteinHPV18 L1 proteinpapillomavirus major capsid protein L1

Induction of neutralizing antibodies: L1 virus-like particles elicit a strong humoral immune response that prevents viral entry into host cells[2][5][7]. Inhibition of virus-host binding: Specific L1 peptides can block HPV VLP binding to target cells[5].