Suppressive effects of intravenous immunoglobulin (IVIG) on human umbilical cord blood immune cells.

We investigated in vitro immunomodulatory effects of intravenous immunoglobulin (IVIG) on cord blood mononuclear cells (CBMNC), macrophages, dendritic cells and CD3(+) T cells were isolated from umbilical venous blood. Cell proliferation used H-3-TdR incorporation, culture supernatants were assayed for cytokines using ELISA, and surface marker expressions were determined by flow cytometry. IVIG suppressed CBMNCs and CD3(+) T-cells proliferation, secretions of IL-10, INF-gamma and TGF-beta(1), but not IL-4, and PHA-induced expressions of surface molecules (CD25, CD45RA and CD45RO), with more pronounced effects for CBMNCs. IVIG decreased cord blood (CB) macrophage phagocytosis and CD14, HLA-DR and CD86 expressions. IVIG increased CD14 expression and decreased MCH II expression for differentiation-stage CB dendritic cells (DCs) and increased CD14 expression and decreased CD80 and CD83 expressions of mature DCs, suggesting that IVIG intervention inhibited DC differentiation and maturation. In addition to T cells, IVIG immunomodulatory effects on CBMNCs involve a variety of cells and molecules. CB macrophages and CBMNC-DCs are targets of IVIG.