LINEAR B-CELL EPITOPES IN THE N-TERMINUS OF L2 OF BOVINE PAPILLOMAVIRUS TYPE-4

The minor capsid protein L2 of bovine papillomavirus type 4 (BPV-4) is a very effective prophylactic vaccine which induces the production of virus neutralising antibodies and prevents virus-induced papillomatos is. The virus neutralising activity resides in the first 200 N-termina l amino acids of L2 (L2a). To further investigate the humoral immune r esponse to L2, and the role it plays during infection and in prophylac tic vaccination, the presentation of B-cell linear epitopes of L2a has been analysed in calves infected with the virus but not vaccinated, a nd in calves vaccinated with virus, L2a or E7. Several B-cell epitopes have been identified in L2a by the use of overlapping peptides; the e pitopes varied in the different groups of animals, indicating that the epitopes presented by denatured L2 are not presented by the virus, an d that therefore, although responsible for L2 vaccine-induced immunity , they may play little role in naturally acquired immunity.