Abstract
Peritoneal macrophages were used to analyse host genetic control of mouse hepatitis virus type 4 (MHV-4) infection. Both infectious centre and immunofluorescence assays indicated that only a subset of macrophages from either susceptible (BALB, C3H or C57BL/6J) or resistant (SJL/J) mice were initially infected with MHV-4 during the first cycle of infection. However, compared to macrophages from susceptible mice, three- to sixfold fewer SJL/J macrophages were infected, and there was no amplification of virus replication by involvement of adjacent cells during the second cycle of infection. Treatment of macrophages from susceptible mice with interferon beta could not duplicate the aborted second cycle of infection that occurred in macrophages from resistant mice.