@entity33601 access to CNS by extraneural XXXX inoculation.

@entity35 @entity778 @entity33601 @entity646
This study was carried out to determine the pathways along which two strains of @entity33601 (JV), the pathogenic XJV and the attenuated XJC13V, reach the CNS following IP inoculation of 2-day-old @entity35 . A sequential study of infectivity and antigen distribution in peritoneal macrophages, spleen, and brain was performed. Mortality was 85% with the former strain, but only 15% with the latter. At 4-7 days PI, XJV-infected animals had viral antigen in 10% of peritoneal macrophages. @entity646 and spleen virus lasted for 10-15 days. Low brain titers were detected at day 7, with a peak at day 15. Brain antigen correlated with virus titers. In contrast, XJC13V-infected rats, macrophage antigen appeared later and to a lesser degree (1% of cells). @entity646 and spleen virus were transient, while both the @entity778 and the viral antigen proved lower. Antibody titers were over twofold higher for XJ-infected animals. It is suggested that the different replication rate at the inoculation site could account for the greater ability of the XJV strain to reach the CNS. A greater antigen mass and/or more numerous antigenic determinants presented by the macrophage could explain the higher antibody titers found in XJ-injected @entity35 , which were unable, however, to prevent viral spread.
