Mouse hepatitis virus infection of mice causes long-term depletion of lactate dehydrogenase-elevating virus-permissive macrophages and T lymphocyte alterations.

Intraperitoneal injection of pathogen-free B10.A mice with mouse hepatitis virus (MHV)-A59 resulted in a short subclinical infection which was terminated by a rapid antiviral immune response. The infection resulted in a rapid, but transient, about 10-fold increase in the number of macrophages and total cells in the peritoneum of the mice. This increase was preceded by a complete depletion of the peritoneum of the subpopulation of macrophages that supports a productive infection by lactate dehydrogenase-elevating virus (LDV). The depletion of LDV-permissive macrophages was a long-term effect; at 50 days post-infection with MHV, the proportion of LDV-permissive macrophages in the peritoneum had reached only 20% of that observed in the peritoneum of uninfected mice, whereas the total number of macrophages in the peritoneum had returned to normal. Furthermore, MHV infection resulted in a long-term alteration in the proliferative response of spleen T cells to concanavalin A (ConA) and in their ability to produce interferon gamma; several times higher concentrations of ConA were required to induce a maximum proliferative response in spleen T cell populations from 5-week MHV-infected B10.A mice than in spleen T cell populations from infected companion mice but the former produced 5 times more interferon gamma than the T cells from uninfected mice.