Interferon immunosuppression: mediation by a suppressor factor

Suppression of the in vitro antibody response to sheep erythrocytes by mouse fibroblast interferon occurred by induction of suppressor cell activity in spleen cells. The suppressor cells produced a soluble factor which mediated the immunosuppression. The suppressor factor did not inhibit virus replication; thus, interferon probably regulates the B-cell response by a mechanism that is different from its antiviral effect.