Coronavirus JHM OMP1 pathogenesis in owl monkey CNS and coronavirus infection of owl monkey CNS via peripheral routes

Abstract

Two separate studies are described in this report. First, 5 Owl monkeys were inoculated intracerebrally (IC) with coronavirus JHM OMP1; this virus isolate was cultured from the brain of an animal inoculated with uncloned MHV JHM. Two of the animals became neurological impaired and were sacrificed; these animals had developed severe encephalomyelitis as previously described. Two of the remaining 3 healthy animals were inoculated IC again at 90 days post-inoculation (DPI) and all 3 were sacrificed approximately 5 months after the first virus inoculation. Despite the lack of detectable infectious virus, viral RNA and antigen, all 3 animals had significant white matter inflammation and areas of demyelination in the spinal cord. In the second study 4 Owl monkeys were inoculated intranasally (IN) and ocularly and 4 inoculated intravenously (IV) with JHM OMP1. The animals were sacrificed between 16 and 215 DPI with 2 IN and 2 IV animals receiving a second IV inoculum at 152 DPI. Viral RNA and/or antigen was detected in the brains of all animals and the distribution corresponded to areas of inflammation and edema. One of the animals that received the second inoculum developed neurological impairment and subsequent analysis of tissues showed viral antigen in both brain and spinal cord. Viral products were predominantly found in blood vessels suggesting hematogenous spread with entry into the central nervous system (CNS) through endothelium.