Immunopathology of mouse hepatitis virus type 3 infection: IV. MHV 3-induced immunodepression

Abstract

Humoral immunity was studied in mice during the development of MHV 3-induced persistent infection. Sequential determinations of immunoglobulins showed a progressive decrease of all Ig levels during the first 3 months of infection, followed by a return to normal levels. When tested 40 and 80 days after infection, primary and secondary PFC responses and serum antibody titers against SRBC and LPS were markedly diminished, in paralyzed as well as in nonparalyzed mice. Conversely, anti-MHV 3 antibody titers reached maximal levels by Day 90, slowly decreasing thereafter. MHV 3 was recovered from brain and liver and from peritoneal macrophages during the first 3 months of infection only. MHV 3-induced immunodeficiency observed during the chronic phase of the disease seems to be related to virus-induced lympholysis and inhibition of lymphocyte proliferation.