Isolation and characterization of a cytomegalovirus from the salivary gland of a squirrel monkey (Saimiri sciureus)
Rangan, S.R.; Chaiban, J.
Laboratory Animal Science 30(3): 532-540
1980
ISSN/ISBN: 0023-6764 PMID: 6253743 Document Number: 167778
Plaque-like areas of cytopathic effect developed in the monolayers that grew out from the trypsinized salivary gland cell suspensions of an adult squirrel monkey. Cells in these areas contained intranuclear inclusions. The cytopathic effect progressed upon subculture with the appearance of floating round cells over a monolayer of a mixture of round, fibroblastic and epithelial-type cells. Intranuclear and cytoplasmic virus particles with the typical morphological characteristics of herpesviruses were seen in the cultures. A virus, designated SqSHV and isolated from the frozen and thawed culture harvests, induced a cytopathic effect in fetal squirrel monkey lung cultures similar to that seen in the original salivary gland cultures. The virus had an in vitro host range restricted to cells of primate origin. Replication of SqSHV was more efficient in squirrel monkey or marmoset cells compared to those from a chimpanzee or human. While immunofluorescent and neutralizing antibodies against SqSHV were prevalent in feral squirrel monkeys in breeding colonies, a group of adult squirrel monkeys nursery-reared from birth were free of the virus infection. Horizontal transmission of SqSHV occurred among squirrel monkeys when infection-free animals were kept in contact with infected ones. Several New and Old World primate sera screened reacted with SqSHV-induced antigens in fluorescent antibody tests. A bi-directional antigenic cross-reactivity was observed between SqSHV and cytomegaloviruses derived from rhesus and African green monkeys by the immunofluorescence method. The SqSHV seropositive heterologous primate species sera were free of neutralizing antibodies to the virus. The SqSHV was distinguished from human, rhesus and African green monkey cytomegaloviruses by serum neutralization or immunofluorescence titrations. The SqSHV differed from the primate cytomegaloviruses in its relative ability to replicate in squirrel monkey lung cells. Based on the morphology, site of isolation, in vitro properties and antigenic characteristics, SqSHV was considered as a cytomegalovirus of squirrel monkeys.