Impairment by interferon of mitogen-induced DNA synthesis in chick lymphocytes.

Chick interferon preparations inhibit mitogen-induced DNA synthesis of chicken peripheral and spleen lymphocytes. Mock interferon preparations showed also some inhibition of mitogen-induced DNA synthesis. The degree of inhibition is concentration dependent but varies also with the relative time of addition of homologous interferon and mitogen. Addition of the interferon preparations 6 h before mitogen resulted in a stronger inhibition of DNA synthesis than if the interferon preparations and mitogen were added at the same time. The interferon preparations seem to affect the metabolism of lymphocytes in a mroe general way and not only the trigger mechanism of the mitogenic response since addition of interferon even 24 h after the mitogen inhibits the induced DNA synthesis.