Attempts to Relate Bovine Papilloma Virus to the Cause of Equine Sarcoid: Horses, Donkeys and Calves Inoculated with Equine Sarcoid Extracts

Abstract

Summary Attempts to produce equine sarcoids in horses and warts in calves with extracts of equine sarcoids were unsuccessful. The horses and calves were later demonstrated to be susceptible to bovine papilloma virus (BPV). Tumours were produced in 2 of 5 donkeys 5 to 10 months after inoculation with extracts of equine sarcoids. This was a longer interval than has been observed for tumour formation by BPV. The tumours did not histologically resemble equine sarcoids or BPV‐produced tumours of equine skin. Résumé Des tentatives pour produire à l'aide d'extraits de tumeurs sarcoides équines soit des tumeurs sarcoides chez le cheval soit des verrues chez le veau ont échoué. Ultèrieurement on montra que les chevaux et les veaux étaient réceptifs au virus de la papillomatose bovine. Des tumeurs furent induites sur deux anes parmi cinq sujets inoculés avec des extraits de tumeurs sarcoides équines (tumeurs apparues cinq à dix mois plus tard). L'apparition des tumeurs fut moins rapide que celles obtenues avec le virus de la papillomatose bovine. Les tumeurs ne ressemblaient point aux sarcoides du cheval ni aux tumeurs induites chez le cheval par le virus de la papillomatose bovine. Zusammenfassung Versuche beim Pferd das Sarcoid oder beim Kalb Warzen mit Extrakten von equinem Sarcoid zu reproduzieren sind misslungen. Die Tiere erwiesen sich aber später als empfänglich für das Virus der bovinen Papillomatose. Tumoren konnten erzeugt werden bei 2 von 5 Eseln mit Sarcoidextrakten 5 bis 10 Monate nach der Inokulation. Das Intervall ist länger als dasjenige, das für die Tumorbildung durch das Virus der bovinen Papillomatose bekannt geworden ist. Die Tumoren glichen aber histologisch weder dem equinen Sarcoid noch dem Tumor, der durch das Virus der bovinen Papillomatose in der Haut des Pferdes hervorgerufen werden kann. Sumario Los intentos de producir sarcoides equinos do caballos y mesquinos transfer ridos a bovinos fué con éxito. Los caballos y vacas fueron suceptibles al papiloma virico del bovino (EPV). Se producieron tumores en burros 2 de 5 con estractos de sarcoides equinos de 5 a 10 meses despúes de inoculados con extracto de sarcoides equinos. Este fúe el intervalo mas largo que se ha observado en la formacíon de tumores por BPV. Los tumores histologicamente no son parecidos de los sarcoides equinos o BPV producidos como tumores de la piel.

Association of bovine papillomavirus with the equine sarcoid

“…In the case of equine sarcoids, although BPV DNA has been detected widely and mRNA expression for L1 has been shown , there is little evidence for expression of the BPV structural proteins or for virus capsid formation (Reid, 1992). This is supported by the observation that experimental inoculation of sarcoid extracts in cattle does not induce warts (Ragland & Spencer, 1969). Therefore, BPV infection of equine fibroblasts appears to be non-productive.…”

“…Subsequently, more substantial evidence was provided by transmission studies in which inoculation with either sarcoid tissue or cell-free supernatant from minced tumours onto the scarified skin of sarcoid-free horses resulted in the appearance of tumours at the inoculation site; these sarcoids were morphologically indistinguishable from naturally occurring sarcoids (Voss, 1969). Similarly, inoculation with bovine papillomavirus (BPV) in nonaffected horses resulted in the growth of sarcoid-like tumours (Olson & Cook, 1951;Ragland & Spencer, 1969). However, the artificially induced sarcoids showed spontaneous regression, which is rarely encountered in naturally occurring sarcoid tumours.…”

“…Although a virus has been suspected as a causative agent (Olson & Cook, 1951;Ragland & Spencer, 1969), no papillomavirus has been isolated from clinical cases. Studies on a cell line derived from an equine sarcoid (the MC-1 cell line) and on a cell line derived from a tumour induced by inoculation of a combined immunodeficient foal with MC-1 cells (the T-77-4 cell line) revealed the presence of virus particles containing high molecular mass RNA genomes and reverse-transcriptase activity (England et al, 1973;Fatemi-Nainie et al, 1982, 1984Cheevers et al, 1982).…”

Localization of Bovine papillomavirus in equine sarcoids and inflammatory skin conditions of horses using laser microdissection and two forms of DNA amplification

“…3,9,17,22,23,25 Studies have demonstrated the location of BPV in sarcoids using in situ hybridization, 14,25 but while this technique allows for the visualization of BPV, it does not amplify the BPV genome to any significant degree when compared to PCR and is, therefore, a much less sensitive technique for identification of DNA when it is present in small quantities. 17 Laser microdissection (LM) allows for the very precise excision of a cell or cells from a sample of interest.…”

Localization of Bovine Papillomavirus Nucleic Acid in Equine Sarcoids

“…26,29,34 In subsequent work, Southern blots were used to identify BPV1 or BPV2 genome(s) within tumor tissue, 1,2,19,38 and polymerase chain reaction (PCR)-based surveys routinely demonstrate that up to 100% of sarcoids contain BPV DNA. [12][13][14]23,24,27,38,39 A limited number of studies have been designed to investigate the role of BPV in cellular transformation in equine tissue.…”