Alcelaphine herpesvirus 1 genes A7 and A8 regulate viral spread and are essential for malignant catarrhal fever

Myster, F., Gong, M.-J., Javaux, J., Suárez, N. M., Wilkie, G. S., Connelley, T., Vanderplasschen, A., Davison, A. J. and Dewals, B. G. (2020) Alcelaphine herpesvirus 1 genes A7 and A8 regulate viral spread and are essential for malignant catarrhal fever. PLoS Pathogens, 16(3), e1008405. (doi: 10.1371/journal.ppat.1008405) (PMID:32176737) (PMCID:PMC7098659)

Abstract

Alcelaphine herpesvirus 1 (AlHV-1) is a gammaherpesvirus that is carried asymptomatically by wildebeest. Upon cross-species transmission to other ruminants, including domestic cattle, AlHV-1 induces malignant catarrhal fever (MCF), which is a fatal lymphoproliferative disease resulting from proliferation and uncontrolled activation of latently infected CD8+ T cells. Two laboratory strains of AlHV-1 are used commonly in research: C500, which is pathogenic, and WC11, which has been attenuated by long-term maintenance in cell culture. The published genome sequence of a WC11 seed stock from a German laboratory revealed the deletion of two major regions. The sequence of a WC11 seed stock used in our laboratory also bears these deletions and, in addition, the duplication of an internal sequence in the terminal region. The larger of the two deletions has resulted in the absence of gene A7 and a large portion of gene A8. These genes are positional orthologs of the Epstein-Barr virus genes encoding envelope glycoproteins gp42 and gp350, respectively, which are involved in viral propagation and switching of cell tropism. To investigate the degree to which the absence of A7 and A8 participates in WC11 attenuation, recombinant viruses lacking these individual functions were generated in C500. Using bovine nasal turbinate and embryonic lung cell lines, increased cell-free viral propagation and impaired syncytia formation were observed in the absence of A7, whereas cell-free viral spread was inhibited in the absence of A8. Therefore, A7 appears to be involved in cell-to-cell viral spread, and A8 in viral cell-free propagation. Finally, infection of rabbits with either mutant did not induce the signs of MCF or the expansion of infected CD8+ T cells. These results demonstrate that A7 and A8 are both essential for regulating viral spread and suggest that AlHV-1 requires both genes to efficiently spread in vivo and reach CD8+ T lymphocytes and induce MCF.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Suarez, Dr Nicolas and Wilkie, Dr Gavin and Davison, Professor Andrew

Creator Roles

Suárez, N. M.: Methodology
Wilkie, G. S.: Methodology
Davison, A. J.: Funding acquisition, Writing – review and editing

• Authors: Myster, F., Gong, M.-J., Javaux, J., Suárez, N. M., Wilkie, G. S., Connelley, T., Vanderplasschen, A., Davison, A. J., and Dewals, B. G.
• College/School: College of Medical Veterinary and Life Sciences > School of Infection & Immunity; College of Medical Veterinary and Life Sciences > School of Infection & Immunity > Centre for Virus Research
• Journal Name: PLoS Pathogens
• Publisher: Public Library of Science
• ISSN: 1553-7366
• ISSN (Online): 1553-7374
• Published Online: 16 March 2020
• Copyright Holders: Copyright © 2020 Myster et al.
• First Published: First published in PLoS Pathogens 16(3): e1008405
• Publisher Policy: Reproduced under a Creative Commons License

Project Code	Award No	Project Name	Principal Investigator	Funder's Name	Funder Ref	Lead Dept
65632	1	Genomics of human cytomegalovirus	Andrew Davison	Medical Research Council (MRC)	MC_UU_12014/3	MVLS III - CENTRE FOR VIRUS RESEARCH