In the experiments, reported in the advanced, online issue of the journal Molecular Therapy, the researchers used a strain of mouse with basically the same genetic defect and symptoms as humans with sickle cell disease. The scientists introduced the gene for gamma-globin into the mice's blood-forming cells and then introduced those altered cells into the mice.
The investigators found that months after they introduced the altered blood-forming cells, the mice continued to produce gamma-globin in their red blood cells.
"When we examined the treated mice, we could detect little, if any, disease using our methods," said Persons, the paper's senior author. "The mice showed no anemia, and their organ function was essentially normal."
The researchers also transplanted the altered blood-forming cells from the original treated mice into a second generation of sickle cell mice to show that the gamma-globin gene had incorporated itself permanently into the blood-forming cells. Five months after that transplantation, the second generation of mice also showed production of fetal hemoglobin and correction of their disease.
"We are very encouraged by our results," Persons said. "They demonstrate for the first time that it is possible to correct sickle cell disease with genetic therapy to produce fetal hemoglobin. We think that increased fetal hemoglobin expression in patients will be well tolerated and the immune system would not reject the hemoglobin, in comparison to other approaches."
While Persons believes that the mouse experiments will lead to treatment
|Contact: Summer Freeman|
St. Jude Children's Research Hospital