Suppression of established Friend virus leukemia by statolon. I. Demonstration of a latent infection in clinically normal mice.

A single inoculation of statolon into mice with established Friend virus (FV) leukemia can suppress the viral infection and produce a clinical remission lasting many months. Eventually, however, most of the mice develop characteristic FV leukemia. Persistence of FV activity in the spleens of mice during clinical remission can be demonstrated by cell transfer and histopathologic studies. Transfer to normal mice of a large number of spleen cells (10(7)) from mice in remission produces FV leukemia, and transfer of a small number of cells (10(2)) produces immunity to FV challenge. Histopathologic examination reveals clusters of abnormal FV leukemia-like cells directly beneath the capsules of the spleens of mice in clinical remission.