title: Partial correction of murine beta-thalassemia with a gammaretrovirus vector for human gamma-globin.
abstract: Several studies have demonstrated that recombinant lentivirus vectors containing extended globin gene expression cassettes and regulatory elements can ameliorate the pathogenic sequela in murine models of beta-thalassemia and sickle cell disease. Similarly promising results have not yet been obtained with recombinant gammaretrovirus vectors. Of these two vector classes, only gammaretroviruses have been tested extensively in clinical trials, with a proven ability to transduce long-term reconstituting hematopoietic stem cells with an exceedingly low incidence of serious side effects. Toward the continuing goal of developing retrovirus vectors for the treatment of the beta-chain hemoglobinopathies, we report here the assessment of a recombinant gammaretrovirus vector for human gamma-globin in murine models of beta-thalassemia. In the beta-thalassemia intermedia Hbbth-3/+ model, we observed a dose-dependent but transient increase in total hemoglobin and red blood cells, with a 2.5 +/- 0.2 g/dL increase in hemoglobin for transduction rates > or = 33%. In the severe beta-thalassemia major Hbbth-3/Hbbth-3 model, we observed a modest but statistically significant increase in survival, from a median of 15 days to 30 days (P = 0.001). These studies provide the first evidence that globin gene transfer vectors based on recombinant gammaretroviruses may provide a viable option for the treatment of the beta-chain hemoglobinopathies.
authors.affiliation: University of Washington, Department of Medicine, Division of Medical Genetics, HSB K236F, University of Washington, Seattle, WA 98195-7720, USA.
authors.forename: Tamon
authors.initials: T
authors.lastname: Nishino
authors.forename: Julie
authors.initials: J
authors.lastname: Tubb
authors.forename: David W
authors.initials: DW
authors.lastname: Emery
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004906:Erythrocyte Count; D017988:Gammaretrovirus; D015316:Genetic Therapy / Q000379:methods; D005822:Genetic Vectors / Q000627:therapeutic use*; D005914:Globins / Q000008:administration & dosage* / Q000235:genetics; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D051379:Mice; D012313:RNA / Q000627:therapeutic use; D015996:Survival Rate; D017086:beta-Thalassemia / Q000628:therapy*
chemical_list: D006454:Hemoglobins; C039919:RNA, recombinant; D012313:RNA; D005914:Globins