Characterization of Splenic Cells during the Early Phase of Infection with Neuropathogenic Mouse Hepatitis Virus

Abstract

The highly neuropathogenic cl-2 and less virulent srr7 viruses isolated from the neurotropic JHM strain of the mouse hepatitis virus exhibit super acute spread of virus (SAS), a term applied when rapid viral spread from an organ or part of the initially infected site to another non-adjacent organ or part is detected within 12 h after infection. Herein, we used a cytospin procedure to confirm SAS in splenic cells derived from mice whose brains were infected with these viruses. The cytospin procedure enabled effective preservation of the cells on glass slides. With this method, we could characterize extremely low populations of infected cells in the spleen (less than 0.1%) at 12 h post-inoculation with srr7. We observed that all kinds of splenic cells examined were infected, including B220⁺Ly-6C⁺ plasmacytoid dendritic cells. The population of viral antigen-positive splenic cells was only slightly higher in cl-2 infection than in srr7 infection, but the cells showing viral production were present in numbers significantly higher in cl-2 infection compared with srr7 infection.