|Budget Amount *help
¥5,400,000 (Direct Cost : ¥5,400,000)
Fiscal Year 1998 : ¥5,400,000 (Direct Cost : ¥5,400,000)
Chronic granulomatous disease (CGD) is an inherited immune deficiency caused by mutations in any of the following four phox genes encoding subunits of the superoxide generating phagocyte NADPH oxidase. It consists of membranous cytochrom b558 composed of gp9lphox and p22phox, and four cytosolic components, p47phox, p67phox, rac p21 and p40phox, which translocate to the membrane upon activation.
In our group study, more than 220 CGD patients has been enrolled. The incidence of CGD patients was estimated as I out of 250,000 births. The expected life span of the COD patients is 25 to 30 years old by the Kaplan Meier analysis. Comparing with the ratio of CGD subtype in US and Europe, that with p47phox deficiency is lower (less than 10% vs. 23%) and that of gp9lphox deficiency is higher (more than 75% vs. 60%). Prophylactic administration of ST antibiotics and IFN-gamma and bone marrow transplantation have been successfully employed in our therapeutic strategy. However, it is necessary to de
velop the gene therapy technology for CGD patients as more promising treatment.
In the current study we constructed three retrovirus vectors ; MFGS-gp91/293 SPA which contains only the therapeutic gp91phox gene, a bicistronic retrovirus pHa-MDR-IRES-gp91/PA317 which carries a multi drug resistant gene (MDR1) and the gp9lphox gene connected with an internal ribosome entry site (IRES), and a pHa-gp9l-IRES-Neo/PAMP51 which carries downstream ('3) neomycin phosphotransferase gene (Neo^r) in place of the farmer upstream MDR1 gene. We demonstrate high efficiency transduction of gp9lphox to COD EB virus established cell line with high levels of functional correction of the oxidase by MFGS-gp91 and by pHa-MDR-IRES-gp9l or pHa-gp9l-JRES-Neo by an appropriate selection with vincristine or G418, respectively. We also demonstrate sufficient transduction of gp9lphox to CD34+heamatopoietic stem cell from the patients with gp9lphox deficiency by MFGS-gp9l/293 SPA.
Our current studies suggest that the combination of the 293-SPA or PAMP5I packaging system and the bicistronic retrovirus system inserted MDR1 gene make our COD gene therapy more feasible for clinical application. Less