Potentiation of cytokine-induced proliferation of human Natural Killer cells by intravenous immunoglobulin G.

Abstract Intravenous IgG (IVIG) therapy can be used for immunomodulation. IL-2 is an immunoregulatory cytokine. We evaluated IVIG modulation of human blood lymphocyte response to IL-2 and other cytokines. Neither IVIG nor low concentrations of IL-2 (3–30 U/ml) induced lymphocyte proliferation, but in combination they synergistically enhanced proliferation of NK cells. The CD56 bright cells expanded more than CD56 dim NK cells, with 90% of NK cells dividing up to 8 generations by day 6, while