NF-κB inhibition leads to increased synthesis and secretion of MIF in human CD4+T cells (48.2)

Abstract

Abstract To examine the effects of NF-κB inhibition on the secretion of macrophage migration inhibitory factor (MIF) in CD4+ T cells. Isolated human CD4+ T cells were cultured with NF-κB inhibitors for 24 hrs. MIF levels were evaluated by intracellular FACs, ELISA, and real time PCR. The levels of intracellular O2-, H2O2, and glutathione were evaluated by intracellular FACs. The amounts of phosphorylated Akt and c-Jun were measured by Western blotting. Treatment of CD4+ T cells with NF-κB inhibitors resulted in a significant increase of MIF concentration in culture supernatants, MIF gene expression and O2- production and decrease of intracellular MIF, H2O2, and GSH. Treatment with LY294002, and SP600125 suppressed NF-κB inhibitors induced MIF mRNA expression and MIF secretion and inhibited parthenolide induced phosphorylation of Akt and c-Jun. Treatment with H2O2 also decreased the amounts of intracellular MIF protein and increased MIF level in the culture supernatant. NAC, an antioxidant precursor of GSH, inhibited parthenolide or H2O2 induced secretion of MIF. These results indicate inhibition of NF-κB leads to release of MIF through de novo synthesis of MIF and secretion of preformed MIF in CD4+ T cells through reactive oxygen species production. .