Consistent detection of bovine papillomavirus in lesions, intact skin and peripheral blood mononuclear cells of horses affected by hoof canker.

This research paper investigates the relationship between bovine papillomavirus (BPV-1/-2) and equine hoof canker, a chronic disease in horses. It revealed that BPV-1/-2 was consistently present in canker tissue, skin, and blood cells of canker-infected horses, suggesting that the virus likely contributes to the development of the disease.

Methodology

• The study utilized PCR-based techniques to evaluate canker tissue, intact skin, and peripheral blood mononuclear cells (PBMCs) of 25 horses affected by the disease. The team targeted sarcoid-associated BPV-1 and -2.
• The DNA isolates from 24 canker cases, 13 skin cases and 11 PBMC cases tested positive for BPV-1/-2 DNA.
• Full-length BPV episomes were detected in one out of five canker specimens using inverse PCR.
• DNA from viral early and late genes was sequenced from canker, intact skin, and PBMC DNA in two cases, revealing a 98% identity to BPV-1.
• Quantitative PCR gauged viral DNA loads to account for up to 16 copies per cell in canker tissue and skin, and up to 0.35 copies per PBMC.

Results

• Using RT-PCR, it was found that the major viral oncogene E5, associated with tumor growth in cattle, was being transcribed in two out of four canker tissue specimens and five out of seven PBMC isolates. This suggested active viral replication and infection.
• One canker and one skin sample were also found to have capsomere-associated viral DNA, associated with the viral capsid structure, through immunocapture PCR.
• Interestingly, in 13 individuals with no signs of canker or BPV-related issues, neither hoof tissue, skin, nor PBMCs exhibited any BPV-1/-2 presence across the experiments.

Conclusion

• The consistent presence of BPV-1/-2 in horses affected by canker suggests a vital role of these viruses in the disease’s progression, and hence, the findings point out an active contribution of these viruses to hoof canker disease.
• In light of these results, the researchers suggest that antivirals or immune modulators might help improve canker therapy by targeting BPV-1/-2, though further investigation is needed.