Self-assembly of human papillomavirus type 16 capsids by expression of the L1 protein in insect cells

The L1 major protein of human papillomavirus type 16 was expressed in Sf-21 insect cells with a recombinant baculovirus vector. Virus-like particles similar in appearance to empty virions were identified by electron microscopy at densities of 1.29-1.30. Purified particles reacted with monoclonal anti-HPV-16-L1 antibody in Western blot and immuno dot blot suggesting that conformational epitopes are present in the recombinant particles. Immunodot blot assays using human sera correlated with the detection of HPV-16 DNA by the polymerase chain reaction. The results suggest that HPV-16-L1 virions produced by the baculovirus system might be useful for developing serologic tests to measure antibodies to conformational epitopes and may offer potential for vaccine development.