?T87Q-Globin Gene Therapy Reduces Sickle Hemoglobin Production, Allowing for Ex Vivo Anti-sickling Activity in Human Erythroid Cells.

ABSTRACT: Lentiviral addition of ?T87Q-globin, a modified ?-globin with an anti-sickling mutation, is currently being used in gene therapy trials for sickle cell disease (SCD) and ?-thalassemia patients. ?T87Q-globin interferes with sickle hemoglobin (HbS) polymerization. Here, we generated the SCD mutation in an immortalized human erythroid cell line (HUDEP-2) to investigate the anti-sickling activity of ?T87Q-globin. Sickle HUDEP-2 (sHUDEP-2) cells produced robust HbS after differentiation and sickled under deoxygenated conditions, comparable with SCD CD34+ progeny. Lentiviral transduction provided 9.5-26.8 pg/cell ?T87Q-globin (R2 = 0.83) in a vector copy number (VCN)-dependent manner, resulting in a significant reduction of sickling ratios (R2 = 0.92). Interestingly, ?T87Q-globin transduction markedly reduced endogenous ?S-globin (R2 = 0.84) to an undetectable level (0.4-16.8 pg/cell) in sHUDEP-2 cells, as well as endogenous ?-globin in human CD34+ cell-derived erythroid cells. RNA sequencing (RNA-seq) analysis with ?T87Q-transduced sHUDEP-2 and human CD34+-derived cells revealed activation of inflammation- and proliferation-related programs, suggesting minimal changes in background gene expression except for ?T87Q-globin expression and endogenous ?/?S-globin suppression. In summary, using sHUDEP-2 and CD34+-derived cells, we demonstrated that lentiviral addition of ?T87Q-globin strongly reduced endogenous ?-/?S-globin expression, resulting in an anti-sickling effect. Our findings should be helpful to understand the anti-sickling effects of therapeutic genes in SCD gene therapy.

SUBMITTER: Demirci S 

PROVIDER: S-EPMC7210457 | biostudies-literature | 2020 Jun

REPOSITORIES: biostudies-literature