Role of interferon-gamma in immune cell regulation.

In 1965 Wheelock reported that phytohemagglutinin could induce from human leukocytes an interferon-like virus inhibitor [1]. This substance, which turned out to be interferon-gamma (IFN-gamma), has been the subject, directly or indirectly, of thousands of scientific publications since that initial report. Past research has led to the general conclusion that IFN-gamma is much more than an interferon in that it has broader effects on the various arms of the immune system than most any other lymphokine or cytokine. In this review we discuss the effects of IFN-gamma on the various cell lineages of the immune system, focusing on the biology of its actions. In addition, we summarize research focused on the consequences of introducing IFN-gamma cDNA into tumor cells, aberrant IFN-gamma production in transgenic animals, and inhibition of IFN-gamma effects by knocking out either the IFN-gamma gene itself or the IFN-gamma receptor gene.