Use this URL to cite or link to this record in EThOS: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.465508
Title: In vivo and in vitro studies on bovine papilloma virus
Author: Meischke, Heiko Rogier Christiaan
ISNI:       0000 0001 3392 4128
Awarding Body: University of Glasgow
Current Institution: University of Glasgow
Date of Award: 1978
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Abstract:
An abattoir survey reported an overall teat papillomatosis prevalence of 36% in 721 cattle examined. Affected animals possessed an average of five papillomas on each of two affected teats. Significant sex differences occurred in the prevalence of the disease, and nulliparous female cattle had significantly fewer affected teats than parous females. Morphologically separable lesions were seen and on histological examination were shown to be papillomas, fibropapillomas and focal epithelial hyperplasia-like lesions. Bovine papilloma virus was extracted from all three lesion types. Electron microscopic examination revealed that BPV extracted from teat papilloma, fibropapilloma and focal epithial hyperplastic lesion had significantly different particle diameters. Polyacrylamide gel electrophoresis of BPV from cutaneous fibropapillomas showed a major capsid protein band which has a consistently higher apparent molecular weight than teat lesion extracts. Epidemiological evidence suggested the presence of at least two separate virus/ host interactions were present since the distributions of the individual teat lesions differed in both number and shape of curves When single case, single lesion type BPV extracts were inoculated into experimental calves, four morphologically separable lesions resulted. BPV from teat and cutaneous fibropapillomas produced cutaneous fibro-papillomas which were morphologically indistinguishable from each other; BPV from anogenital fibropapillomas produced cutaneous fibropapillomas morphologically separable from those above; BPV from teat papilloma and focal epithelial hyperplastic lesions produced papilloma and focal epithelial hyperplastic lesions respectively on transmission to normal bovine skin. BPV was extracted from all transmitted lesions. Experimental calves were challenged with BPV from all five lesion types and a differential immunity was demonstrated. The fibropapilloma calves were immune to challenge with most but not all fibropapilloma isolates, but susceptible to challenge with teat papilloma and focal epithelial hyperplasia isolates. Conversely papilloma and focal epithelial hyperplasia BPV infected calves remained susceptible to all fibropapilloma isolates and regression of fibropapillomas was not accompanied by the regression of the former lesions. It was considered that two broad virus categories occurred with papilloma and focal epithelial hyperplasia BPV forming one and fibropapilloma BPV the other category. Within these two categories there were morphological and developmental differences suggesting further heterogeneity which may be confirmed with the use of larger numbers of experimental animals. When inoculated intracerebrally, two fibropapilloma BPV isolates produced meningiomas. One isolate was from a single case of cutaneous fibropapillomas. The other was from cutaneous fibropapillomas which appeared along scarification lines of a calf experimentally inoculated with BPV extracted from a pooled sample of alimentary lesions. A third calf, intracerebrally inoculated with BPV from single case teat focal epithelial hyperplastic lesions, developed similar lesions at intradermal sites but did not develop a meningioma. In vitro, foetal bovine skin, conjunctiva, palate and meninges derived cell cultures were shown to be sensitive to transformation by BPV extracted from fibropapillomas but not papillomas and focal epithelial hyperplastic lesions. Only two skin cultures were sensitive and both of these came from near-term foetuses. Cultures from the pia mater and arachnoidea were sensitive while dura mater derived cultures were not. The in vitro transformation assay was developed and shown to be more sensitive and precise than haemagglutination, however the two systems probably measure different parameters. No significant differences occurred in the transformation titre of two BPV isolates when different tissues of the same foetus and the same tissues of different foetuses were used. BPV transformed cells were shown to be tumourigenic in nude mica but not in calves following intracerebral, subcutaneous, intradermal and submucosal injection., However, inoculated calves showed an increased in vivo resistance to challenge with fibropapilloma derived BPV but not papilloma or focal epithelial hyperplasia derived BPV. BPV-transformed cells showed an increased lifespan when compared with control cultures.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.465508  DOI: Not available
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