Immunization against bovine papillomavirus infection* WILLIAM P. PILACINSKI, DONALD L. GLASSMAN, KIMBERLY F. GLASSMAN, DAVID E. REED, MELISSA A. LUM, RICHARD F. MARSHALL, CHARLES C. MUSCOPLAT and ANTHONY J. FARAS Molecular Genetics Inc., zyxwvuts 10320 Bren Road East, Minnetonka, Minnesota 55343, USA Abstract. The two large open reading frames denoted L1 and L2 in the non-transforming region of the bovine papillomavirus type 1 (BPV-1) genome have been molecularly cloned to expression in Escherichia coli. Antisera against the E. coli-derived L1 and L2 protein reacted with BPV-1 in both enzyme-linked immunosorbent assays and immunoprecipi- tation reactions. Neutralization of BPV-induced transformation of mouse C127 cells was demonstrated most consistently with antisera against the L1 protein. E. coli-derived L1 protein protected calves against BPV-1 challenge after vaccination. 1986 Papillomaviruses. Wiley, Chichester (Ciba Foundation Symposium 120) p 136-156 Bovine papillomavirus (BPV) produces benign proliferative lesions (warts) on the skin and other epithelial surfaces of cattle, its natural host. Typically the warts regress and disappear within a few months or a year; however, occasionally they become quite large and persist indefinitely. Warts on the teats of dairy cattle may interfere with lactation and penile warts may have an impact on breeding programmes. The presence of warts also affects the value zyxwvut of an animal for show or sale. The BPV virion has a naked, icosahedral capsid and a double-stranded DNA genome of about 8000 base pairs (bp) and is closely related to viruses that infect humans, dogs and rabbits (Orth et a1 1978, Law et a1 1979, Jenson et a1 1980). Of the six distinct types of BPV which have been isolated from wart tissue and described (Lancaster zyxw & Olson 1978, Pfister et a1 1979, Campo et a1 1980, W. F. H. Jarrett, unpublished work), BPV-1 and BPV-2 are the predominant types found in warts on dairy and beef cattle in the USA. * The substance of this paper also appears under the title ‘Development of a recombinant DNA vaccine against bovine papillomavirus infection in cattle’ in: Howley P, Broker T (eds) 1985 Papilloma viruses: molecular and clinical aspects. Alan R. Liss, New York (Univ Calif Los Ang Symp Mol Cell Biol New Ser 32), in press. It appears here with permission. 136 Novartis Foundation Symposium Edited by David Evered, Sarah Clark Copyright 0 1986 by Ciba Foundation