CHARACTERISTICS OF CLONED CEREBROVASCULAR ENDOTHELIAL-CELLS FOLLOWINGINFECTION WITH THEILERS VIRUS .2. PERSISTENT INFECTION

Cloned cerebrovascular endothelial cells (CVE) persistently infected w ith Theiler's virus (PI-CVE) have been established and characterized. The CVE were derived from strains of mice that are susceptible (SJL/J and CBA) and resistant (BALB/c) to Theiler's virus-induced demyelinati on (TVID). The cells were persistently infected with either the BeAn o r GDVII strains of Theiler's virus in vitro and studied at various pas sage levels for infectious virus, viral antigen and the expression of major histocompatibility complex (MHC) Class I and II antigens. The vi rus replicated to lower titers than in acutely infected CVE and appear ed to be more cell-associated. Flow cytometric analysis revealed that 18-39% of the PI-CVE contained viral antigen. Persistently infected CV E derived from SJL/J and CBA mice expressed high levels of MHC Class I , whereas BALB/c PI-CVE did not. MHC Class II was upregulated by IFN-g amma in SJL/J PI-CVE albeit at a slightly lower level than in uninfect ed CVE. In addition, the PI-CVE demonstrated increased levels of mRNA for IL-1 beta when compared to uninfected CVE.