Expression of components of the superoxide generating NADPH oxidase by human leucocytes and other cells

Abstract

NADPH oxidase of phagocytic leucocytes contains a membrane cytochromeb with two subunits, gp91phox and p22phox, together with three cytosolic proteins, p47phox, p67phox and p2rac. The presence of some of these components has been sought in non-phagocytes, using Western blot analysis for protein expression and PCR to amplify and detect mRNA. All components were detected in EBV-transformed B lymphocytes and peripheral blood B lymphocytes. Fibroblasts and human kidney mesangial cells contained mRNA for p67phox, p47phox, and p22phox but not gp91phox. Levels of expression varied with growth conditions, but it appears possible than an isozyme of cytochromeb which lacks gp9phox is present in these cells. Proteins of p47phox and p67phox were expressed, in low concentrations, in these two cell types. Expression of mRNA for p47phox and p67phox was found to be widespread in many cell types.