Degree Type

Dissertation

Date of Award

1991

Degree Name

Doctor of Philosophy

Department

Veterinary Pathology

First Advisor

Randall C. Cutlip

Second Advisor

John P. Kluge

Abstract

Immunohistochemical and lung organ culture techniques were developed and used to detect bovine respiratory syncytial virus-infected cell types in ovine lung tissue. Lung tissue was evaluated from sheep inoculated with bovine respiratory syncytial virus (BRSV) and from lung organ slices inoculated with BRSV in vitro. Infected sheep were killed at intervals from 0.5 to 8 days post-inoculation. Histological changes consisted of bronchiolitis, interstitial pneumonitis and pneumonia with exudates of neutrophils, lymphocytes and macrophages. Interstitial infiltrates consisted of peribronchiolar and perivascular lymphocytes and macrophages which extended into alveolar septa. Foci of infection were very sparse as determined by immunohistochemistry. Bovine respiratory syncytial virus antigen was detected in alveolar macrophages in tissues from sheep killed at 0.5 day post-inoculation. Staining for viral antigen was restricted primarily to bronchiolar epithelium and Type I pneumocytes in tissues from sheep killed at 1-6 days post-inoculation. Viral antigen was detected in Type II pneumocytes in tissues from sheep killed at all time periods from 3-6 days post-inoculation. There was no viral antigen detected in tissues collected at 8 days post-inoculation. We failed to detect (BRSV) antigen immunohistochemically at the electron microscopic level because we were unsuccessful in attempts at immunogold staining of BRSV antigen. Virions, identified morphologically, were in association with bronchiolar and alveolar epithelium in tissues from infected sheep;The in vitro portion of this study involved the development of an organ culture technique which allowed viable lung tissue slices to be maintained in vitro for 4 days without histological evidence of tissue necrosis. Cultures of sheep lung slices were inoculated with either BRSV, parainfluenzavirus-3, or ovine adenovirus, immunohistochemical techniques were used to detect infected cells at 0-4 days post-inoculation. Parainfluenzavirus-3 infected the lung slices as determined by immunohistochemical staining. However, immunohistochemical techniques revealed no staining of BRSV or ovine adenovirus antigen in any of the lung slices.

DOI

https://doi.org/10.31274/rtd-180813-9231

Publisher

Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/

Copyright Owner

James Toby Meehan

Language

en

Proquest ID

AAI9126224

File Format

application/pdf

File Size

138 pages

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