[Expression of coagulation factor IX in human CD34 + hematopoietic stem cells by adeno-associated virus 2].

Objective To investigate the expression of huamn coagulation factor Ⅸ (hFⅨ) gene in human umbilical cord blood (CB) CD34~+ cells which was transfected with recombinant adeno-associated virus 2 (rAAV-2). Method The CD34~+ cells were transfected with rAAV-2/hFIX and cultured for 21 days for inducing differentiation into myeloid, erythroid and megakarocytic cells, respectively. The expression of hFⅨ was studied at mRNA, protein and biological activity levels. The cytotoxicity of rAAV-2 to (CD34~+) cells was evaluated by cell proliferation, cell vitality, CD antigen expressions and CFU yields. Results The hFⅨ mRNA was expressed in the cultured cells which was verified by RT-PCR and DNA sequencing. An elevated level of hFⅨ expression and biological activities were detected with a maximum amount of 14.10 ng/10~6 cell·24 h. During the period of 21 day culture, the cell vitality, cell proliferation, CD antigen expression and CFU yields between the transfected and untransfected groups had no difference(P0.05). Conclusion The human CB CD34~+ cells are able to produce functional hFⅨ after transducted by rAAV-2/hFIX. The cell proliferation and differentiation capacities of the host CD34~+ cells were not affected by rAAV-2.