Humoral and Cellular Immune Responses in Susceptible and Resistant Strains of Mice Infected with Friend Leukemia Virus

Summary Infection of susceptible (Balb/c) and resistant (C57Bl) strains of mice with Friend leukemia virus (FLV) revealed a dichotomous effect in terms of immunosuppression to sheep erythrocytes, assessed at the level of individual antibody forming cells and serum hemolysins, and to mycobacterial antigens, assessed at the level of cell-mediated immunity using a macrophage migration inhibition assay. Balb/c mice infected with FLV showed a prompt and prolonged depression of antibody responsiveness to the sheep erythrocytes, as well as marked impairment of cellular immunity to the mycobacterial antigens. In contrast, C57Bl mice, resistant to FLV induced leukemogenesis, showed a transient but significant depression of antibody formation to sheep erythrocytes, but no depression of cell-mediated immunity to mycobacteria. These divergent effects appeared to reflect the relative importance of cell-mediated versus humoral immunity in resistance to leukemia virus induced leukemogenesis.