Biphasic production of immune interferon during mitogen-induced blastogenesis of human peripheral blood mononuclear leukocytes.
Peripheral blood mononuclear leukocytes of 14 healthy blood donors stimulated by concanavalin A were shown to exhibit a biphasic pattern of the production kinetics of interferon. Maximum interferon titers were determined in the culture supernatants 8 and 48 h after addition of the mitogen. Both the early and late interferon production could be abolished by actinomycin D treatment of the induced cells implying that they depend on mitogen-stimulated de novo synthesis of cellular RNA. Under the conditions used the interferon mRNA was accumulated in treated cells during the first 4 h of incubation. The kinetics as well as the efficiency of concanavalin A-induced interferon production turned out to strictly depend on the nature of the protein source added to the culture medium. Only fetal calf serum and calf serum as compared to human albumin or pooled gamma globulin-free human plasma were found to give the highest interferon yields in true biphasic production pattern, thus explaining, at least in part, the differing data obtained by several investigators working with this particular interferon production system.