Gamma Interferon Is a Major Suppressive Factor Produced by Activated Human Peripheral Blood Lymphocytes That Is Able To Inhibit Foamy Virus-Induced Cytopathic Effects

The activation of human peripheral blood lymphocytes by mitogens or by triggering the T-cell receptor with anti-CD3 antibodies leads to the production of a potent soluble inhibitory activity against foamy virus-induced cytopathic effects in vitro. The inhibitory activity acts in a species-specific manner. As a consequence, the isolation of foamy viruses from blood lymphocytes of infected humans is accelerated in a heterologous coculture system. Antibodies against gamma interferon (IFN-γ) are able to suppress most of the inhibitory activity, suggesting that IFN-γ is the dominant component.