Effect of Glucocorticoids on Activation of Leukemia Virus in AKR Mouse Embryo Cells '

The effect ofglucocorticoids on activation and replication of leukemia virus in AKR mouse embryo cells was ana lyzed. The number of cells detected as positive by fluores cent antibody techniques as well as the virus production in cells chronically producing virus was doubled at optimal concentrations of glucoconticoids. The effect of the hor mones in activated cells was found to be not on the process of activation per se but rather on synthesis of the viral components after activation has occurred. Intracellular reverse transcniptase levels were not changed by hormone treatment. The stimulation of virus synthesis by glucocorti coids requires binding of the steroid to a cytoplasmic receptor protein.