The vascular lesions of a cow and bison with sheep-associated malignant catarrhal fever contain ovine herpesvirus 2-infected CD8(+) T lymphocytes.
Malignant catarrhal fever (MCF) is a herpesvirus disease syndrome of ruminants. The microscopic pathology of MCF is characterized by lymphoid proliferation and infiltration, necrotizing vasculitis and epithelial necrosis. Because previous attempts to detect viral antigen or nucleic acids in lesions have been unsuccessful, the pathogenesis of the lesions in acute MCF has been speculated to involve mechanisms of autoimmunity and lymphocyte dysregulation. In this study, the vascular lesions in the brains of a cow and a bison with acute MCF were evaluated by in situ PCR and immunohistochemistry. The results demonstrated that the predominant infiltrating cell type in these lesions was CD8(+) T lymphocytes and that large numbers of these cells were infected with ovine herpesvirus 2. The lesions also contained macrophages, but no detectable CD4(+) or B lymphocytes.
Simon
Susan
S
Department of Veterinary Microbiology, USDA-ARS, Washington State University, Box 647040, Pullman, Washington 99164-7040, USA.
Li
Hong
H
Pathology and Animal Diseases Research Unit, USDA-ARS, Washington State University, Box 647040, Pullman, Washington 99164-7040, USA.
O'Toole
Donal
D
Wyoming State Veterinary Laboratory, University of Wyoming, Laramie, Wyoming 82070, USA.
Crawford
Timothy B
TB
Department of Veterinary Microbiology, USDA-ARS, Washington State University, Box 647040, Pullman, Washington 99164-7040, USA.
Oaks
J Lindsay
JL
Department of Veterinary Microbiology, USDA-ARS, Washington State University, Box 647040, Pullman, Washington 99164-7040, USA.
D000818:Animals; D016164:Bison; D001921:Brain / Q000098:blood supply / Q000276:immunology / Q000821:virology; D018414:CD8-Positive T-Lymphocytes / Q000821:virology*; D002417:Cattle; D002418:Cattle Diseases / Q000276:immunology* / Q000503:physiopathology / Q000821:virology; D018142:Gammaherpesvirinae / Q000302:isolation & purification*; D007150:Immunohistochemistry; D008213:Lymphocyte Activation; D008304:Malignant Catarrh / Q000276:immunology* / Q000503:physiopathology / Q000821:virology; D016133:Polymerase Chain Reaction; D012756:Sheep / Q000821:virology; D012757:Sheep Diseases / Q000821:virology; D014657:Vasculitis / Q000276:immunology / Q000503:physiopathology / Q000662:veterinary*