Purification of papillomavirus structural polypeptides from papillomas by immunoaffinity chromatography

A broadly cross-reactive monoclonal antibody directed against papillomavirus, coupled to immunoaffinity columns, was used to isolate bovine papillomavirus type 1 (BPV-1) and human papillomavirus type 1 (HPV-1) structural polypeptides from homogenates of productively infected cells. One of the polypeptides isolated from bovine fibropapillomas appeared to be the BPV-1 major capsid protein since it had a mol. wt. of 54K and was reactive by Western blots with papillomavirus genus- and BPV-1 type-specific rabbit antibodies as well as monoclonal antibodies cross-reactive with BPV-1/BPV-2 and BPV-1/deer PV. A polypeptide from human plantar warts similarly appeared to be the major capsid component since it also had a mass of 54K to 55K and reacted with papillomavirus genus- and HPV type-specific rabbit antibodies. By using this technique structural viral polypeptides from papillomavirus-induced lesions containing readily detectable viral structural antigens but relatively few virus particles, such as seen with mucosotropic HPVs can now be isolated for mapping of virus-specific epitopes.