Viral load increases in SJL/J mice persistently infected by Theiler's virus after inactivation of the beta(2)m gene

Abstract

We show that inactivating the beta(2)m gene increases the viral load of SJL/J mice persistently infected by Theiler's virus. Together with previous results, this shows that the characteristics of Tmevp1, a locus which controls the amount of viral RNA that persists in the central nervous system, are those of an H-2 class I gene.

FIG. 1

Amount of viral RNA in the CNSs of mice with the wild-type SJL/J, SJL/J β₂m^+/− and SJL β₂m^−/− genotypes. Mice were examined at 6 days p.i. (A), 21 days p.i. (B), and 45 days p.i. (C). The amount of viral RNA is expressed as the highest RNA dilution which gave a hybridization signal in a dot blot assay. The left y axis shows the amount of viral DNA as a dilution factor, whereas the right y axis shows the amount of viral DNA as a score which corresponds to the dilution number in the series. Open bars, spinal cord; solid bars, brain. n, number of animals per group.

FIG. 2

Detection of viral antigens at 45 days p.i. in longitudinal sections of white matter from the spinal cords of wild-type SJL/J (A) and SJL/J β₂m^−/− (B) mice. Viral antigens were detected by immunoperoxidase. Sections were counterstained with hematoxylin. Arrows point to cells containing viral antigens. Magnification, ×200.