Modification of immune response in nude mice infected with mouse hepatitis virus.

In nude mice experimentally infected with mouse hepatitis virus (MHV), the numbers of early and later plaque forming cells (PFC) to sheep red blood cells (SRBC) generated in the spleen were 7 to 20 times and 2 to 163 times, respectively, greater than those in non-infected nude mice, when SRBC were given at day 0 to day 21 postinfection. Splenic theta-positive lymphocytes in infected nude mice were shown to increase only at day 10 or more postinfection. PFC response to bacterial lipopolysaccharide, a T cell-independent antigen, was not modified in MHV-infected nude mice.