Abstract
Friend murine leukaemia virus (FrMLV) FrC6 clone A8 causes spongiform degeneration in the central nervous system (CNS) of newborn but not 3-week-old rats. To assess whether expression of the ecotropic MLV receptor (CAT-1) in the CNS correlates with the pathogenicity of the A8 virus, we generated an anti-CAT-1 antibody raised against a synthetic peptide that corresponds to the carboxyl-terminal amino acid sequence of CAT-1. In the CNS of newborn and 3 to 4-week-old rats, a strong immunoreactivity against the antibody was detected in most of the endothelial cells. However, almost no expression of CAT-1 was detected in the CNS of 21-week-old rats. In newborn rats, many parenchymal cells in the brain as well as the vascular wall expressed CAT-1 antigen. These findings suggest that retrovirus receptor-bearing glial cells contribute to the neuropathogenesis of MLV, including clone A8, which induces spongiosis in rats only when inoculated into newborns.