Bovine papillomavirus (BPV) is a group of DNA viruses of the family Papillomaviridae that are common in cattle. Infection causes warts (papillomas and fibropapillomas) of the skin and alimentary tract, and more rarely cancers of the alimentary tract and urinary bladder. They are also thought to cause the skin tumour equine sarcoid in horses and donkeys. BPV provides an excellent model for studying papillomavirus molecular biology, and also allows the dissection of the processes by which this group of viruses cause cancer. Like other papillomaviruses, BPVs are small non-enveloped viruses with an icosahedral capsid around 50–60 nm in diameter.The capsid is formed of the L1 and L2 structural proteins, with the L1 C-terminus exposed. All BPVs have a circular double-stranded DNA genome of 7.3–8.0 kb. The genetic organisation of those BPVs which have been sequenced is broadly similar to other papillomaviruses. The open reading frames (ORFs) are all located on one strand, and are divided into early and late regions. The early region encodes nonstructural proteins E1 to E7. There are three viral oncoproteins, E5, E6 and E7; BPVs of the Xipapillomavirus group lack E6. The late region encodes structural proteins L1 and L2. There is also a non-coding long control region (LCR) (Wiki: Bovine papillomavirus).
4. Host Ranges and Animal Models
Cattle are the main species affected. BPV-1 and BPV-2 can also induce sarcomas and fibrosarcomas in other mammals, including equids (equine sarcoid) and, experimentally, rabbits, hamsters and mice (Wiki: Bovine papillomavirus).
Newcastle disease virus LS-NDV vaccine stimulates an antibody response and limited increase in TNF-α activity and may enhance clinical recovery in bovine papillomatosis. (Avki et al., 2004)
g.
Cattle Response
Vaccination Protocol:
Fourteen cows were inoculated with an attenuated vaccine containing LS-NDV for two times at 1 week intervals with a total dose of ~10^9.3 egg infective dose50 (EID50) in sterile PBS. Inoculation was performed by s.c. injection in the area where the papillomas were mostly appeared. Four cows inoculated with similar volumes of sterile PBS by the same route and served as controls. (Avki et al., 2004)
Immune Response:
Mean HI titers in inoculated cows on days 7 and 21 were determined as log2 2.43 +/- 0.92 and log2 5.57 +/- 0.72, respectively. Difference between mean antibody levels among the inoculated animals at days 7 and 21 were significantly higher than day 0 (P < 0.05). More significant between day 0 and 21 (P < .001). On day 21 the difference in HI titers between control and inoculated groups was significant (P < 0.05). The mean levels of tumor necrosis factor-a (TNF-a) were 5.80 +/- 4.19 and 5.39 +/- 2.66 ng/ml by WEHI-164 cytotoxicity assay. A correlation was evident between the TNF-a activities and clinical scores on day 21 (r = 0.500; P < 0:05). (Avki et al., 2004)
Side Effects:
These results demonstrated that inoculation of LS-NDV vaccine stimulates an antibody response and limited increase in TNF-a activity and may enhance clinical recovery in bovine papillomatosis. (Avki et al., 2004)
Efficacy:
At day 60, complete recovery was seen in five cows (36%). The papillomas in eight cows regressed (57%). (Avki et al., 2004)
1. Jagu et al., 2011: Jagu S, Malandro N, Kwak K, Yuan H, Schlegel R, Palmer KE, Huh WK, Campo MS, Roden RB. A multimeric L2 vaccine for prevention of animal papillomavirus infections. Virology. 2011; 420(1); 43-50. [PubMed: 21920572].
2. Módolo et al., 2017: Módolo DG, Araldi RP, Mazzuchelli-de-Souza J, Pereira A, Pimenta DC, Zanphorlin LM, Beçak W, Menossi M, de Cassia Stocco R, de Carvalho RF. Integrated analysis of recombinant BPV-1 L1 protein for the production of a bovine papillomavirus VLP vaccine. Vaccine. 2017; 35(12); 1590-1593. [PubMed: 28222997].
