SELECTIVE INFECTION OF ASTROCYTES IN HUMAN GLIAL-CELL CULTURES BY RUBELLA-VIRUS

BACKGROUND: Rubella virus (RV) can cause a wide variety of neurologic symptoms, particularly when infection occurs in utero. However, little is known about the pathogenesis of these infections and the cell type s in human brain susceptible to infection have not been characterized. EXPERIMENTAL DESIGN: Cell cultures derived from human brain tissue we re examined for susceptibility to two wild-type and two vaccine strain s of RV. Cell types expressing viral antigen were identified by double -label immunofluorescence with monoclonal antibodies to specific cell markers and a polyclonal anti-RV antibody. Viral yield was determined by plaque assay. RESULTS: All four RV strains replicated in the brain cultures, although the titers obtained in the case of the vaccine stra ins were more than 100-fold lower than Obese found for wild-type isola tes. Astrocytes appeared to be the main cell type infected, expressing large amounts of viral antigen. In contrast, oligodendrocytes were ra rely productively infected, even when surrounded by infected astrocyte s. Occasional neurons expressing viral antigen were also seen. CONCLUS IONS: The main cell type permissive to RV infection in developing brai n tissue is the astrocyte. Although not highly cytolytic, the virus ma y disrupt the functioning of these cells, resulting in neurologic defi cits. The restricted replication of this virus in oligodendrocytes cor relates with the lack of demyelination generally reported as being typ ical of RV neurologic disease.