BOVINE PAPILLOMAVIRUS TYPE-4 - NEOPLASTIC CELL-TRANSFORMATION AND CONTROL OF INFECTION BY VACCINATION (REVIEW)

Papillomavirus induce benign tumours (papillomas) in a variety of anim als. The papillomas generally regress but occassionally persist and ma y eventually progress to squamous cell carcinoma. One of the most exte nsively studies papillomaviruses is bovine papillomavirus type 4 (BPV4 ). BPV-4 induces papillomas of the upper alimentary canal which are at high risk of progressing to cancer in cattle eating bracken fern. In this review, several aspects of the biology of the virus are described and compared with other papillomavirus systems, including regulation of transcription of the viral oncogenes, function of the viral oncopro teins, cooperation between virus and chemical cofactors, and prophylac tic and therapeutic vaccination programmes.