Abstract
Patients with chronic granulomatous disease (CGD) have recurrent infections resulting from a failure of phagocytic cells to produce superoxide. One third of CGD patients have an autosomal gene defect resulting in absence of p47phox protein, a cytoplasmic component critical to superoxide production by phagocytic cells. cDNA encoding p47phox has been cloned and recombinant p47phox (rp47phox) restores superoxide-generating activity to a cell-free assay containing cell membranes and cytosol from p47phox-deficient CGD neutrophils. The goal of the present study was to determine the feasibility of retrovirus mediated expression of rp47phox in the HL60 and U937 human hematopoietic cell lines, and in an Epstein-Barr virus transformed B- lymphocyte cell line (EBV-BCL) derived from a p47phox-deficient CGD patient. Normal EBV-BCL contain p47phox and generate small amounts of superoxide, while this CGD EBV-BCL lacks any detectable p47phox protein. Defective amphotropic retrovirus containing p47phox sequence inserted in the LXSN vector in sense and antisense orientations were used to transduce HL60, U937, and CGD EBV-BCL. p47phox mRNA sequence was detected in cells transduced with either sense or antisense retroviral constructs while rp47phox protein was detected only with the sense construct. The amount of rp47phox protein produced within these cells was greater than the native p47phox present in uninduced HL60 or U937 cells, but substantially less than that present in normal neutrophils, induced HL60 cells, or even normal EBV-BCL. Differentiation of transduced HL60 cells and the associated production of native p47phox in response to dimethyl sulfoxide was not affected. These studies demonstrate that retrovirus constructs can be used to mediate stable expression of rp47phox protein in human hematopoietic cell lines and can restore rp47phox protein within the cytosol of p47phox-deficient EBV-BCL from patients with CGD.
