Fanconi anemia (FA) is a recessive inherited disease charac- terized by defective DNA repair.FA cells are hypersensitive to DNA cross-linking agents that cause chromosomal insta- bility and cell death.FA is manifested clinically by progres- sive pancytopenia, variable physical anomalies, and predis- position to malignancy.Four complementation groups have been identified, termed A, B, C, and D. The gene for the FA complementation group C, FACC, has been cloned.Expres- sion of the FACC cDNA corrects the phenotypic defect of FA (C) cells, resulting in normalized cell growth in the pres- ence of DNA cross-linking agents such as mitomycin C (MMC).Gene transfer of the FACC gene should provide a survival advantage to transduced hematopoietic cells, sug- gesting that FA might be an ideal candidate for gene therapy.We demonstrated efficient transduction, expression, and phenotypic correction in lymphoblastoid cell lines de- rived from FA (C) patients using a recombinant adeno-asso- ciated virus (rAAV) vector containing the FACC gene.Mo- lecular characterization of the transduced FACC gene showed an intact unrearranged proviral genome with ex- pression sufficient to normalize cell growth, cell cycle kinet- ics and chromosomal breakage in the presence of MMC.These observations were extended by testing rAAV trans- duction in hematopoietic progenitor cells.Peripheral blood CD34+ cells isolated from a FA(C) patient and transduced with rAAV/FACC virus yielded 5-10-fold more progenitor colonies than mock-infected cells, consistent with genetic "rescue" of corrected cells.This is the first demonstration of rAAV gene correction in primary human hematopoietic progenitor cells and has important implications for gene therapy of hematopoietic disorders, specifically FA. (J.Clin.
No takes yet. Share an insight, caveat, or question.
Walsh et al. (2020) studied this question.