|Crawford, T - WASHINGTON STATE UNIV.|
Submitted to: American Society for Virology Meeting
Publication Type: Abstract Only
Publication Acceptance Date: April 7, 2003
Publication Date: July 13, 2003
Citation: Kim, O., Li, H., Crawford, T.B. Identification of in vivo host cell replication sites for sheep-associated malignant catarrhal fever virus. The 22nd Annual Meeting of American Society for Virology. 2003. Abstract. p. 247. Technical Abstract: Ovine herpesvirus-2 (OvHV-2), a member of ruminant rhadinoviruses, asymptomatically infects its natural host, the sheep, but causes a clinical disease syndrome named malignant catarrhal fever (MCF) in other less well-adapted hosts, such as cattle, bison and deer. OvHV-2 has never been isolated and little information is available about its productive replication in vivo. In this study, we identified OvHV-2 replication sites in naturally infected sheep. Six sheep with high OvHV-2 viral DNA copy numbers (ranging from 100,000 to 100,000,000 per 2 ug DNA) in their nasal secretions were selected using real-time PCR. Strong signals were obtained by in situ hybridization in epithelial cells of the mucosa and the submucosal glands of turbinate and trachea from all six sheep. Hybridization signals were only rare found in lung tissue and retropharyngeal lymph nodes. No viral DNA was detected in any other tissues examined from these sheep. Abundant OvHV-2 viral antigens were also detected in the mucosa and the submucosal glands of the turbinate and the trachea by immunofluorescent assay and by immunohistochemistry using a monoclonal antibody directed against an MCF viral glycoprotein complex. Distribution patterns of signals by in situ hybidization and immunohistochemistry were virtually identical. No signals were detected by in situ hybridization, immunofluorecent or immunohistochemical assays in any tissues from sheep with low viral copy numbers (<1,000) in nasal secretions or in any samples from OvHV-2 negative sheep used as controls. These findings indicate that epithelium of turbinate and trachea supports OvHV-2 productive replication in vivo and the respiratory tract is the major port for OvHV-2 transmission.