Inhibitory Effects of Sendai Virus on Friend Virus Leukemia in Mice

Summary

Sendai virus (SV) inoculated before Friend virus (FV) inhibited FV replication in spleens as well as the splenomegalic and leukocytotic responses to FV infection. The response curves in mice of interferon production and of FV leukemia inhibition to increasing doses of SV were similar. Optimal interferon production and FV leukemia inhibition occurred in response to a dose of SV less than the maximum dose tested. SV markedly protected significant numbers of mice from leukemia when it was inoculated as early as 6 weeks before FV. No protection occurred, however, when the interval between virus inoculations was extended to 9 weeks. At least 10% of mice inoculated with SV 3 weeks prior to FV exhibited no signs of leukemia 6 months after all FV control mice had died.