EFFICIENT GENE-TRANSFER INTO CARDIAC MYOCYTES USING ADENOASSOCIATED VIRUS (AAV) VECTORS

Adeno-associated virus (AAV) vectors, derived from a non-pathogenic pa rvovirus, are considered to be an appropriate gene transfer vehicle fo r both dividing and non-dividing cells. In the present study, we inves tigated whether the rat heart could be efficiently transduced with AAV vectors. Rat cardiac myocytes (CM) were infected with AAV-lacZ vector containing beta-galactosidase (beta-gal) gene in vitro, and the expre ssion of beta-gal in CM was evaluated by X-gal staining and beta-gal E LISA, With increasing multiplicities of Infection (MOI), more than 60% of CM were stained positively with X-gal, and the beta-gal expression increased to 31.1 +/- 4.6 ng/mg protein in a MOI-dependent manner (MO I: 10(4) to 10(6) particles/cell). The beta-gal expression was also in creased in an incubation period-dependent manner (1-24 h). beta-gal ex pression was maximal at day 3 and then gradually decreased with time, However, beta-gal expression at day 14 was almost the same level as th at at day 1 (45.5 +/- 5.9 v 55.2 +/- 6.2 ng/mg protein). Excised rat r ight ventricular papillary muscles were also infected with AAV-lacZ ex vivo, When the beta-gal expression was evaluated by X-gal staining, m ore than 80% of CM in the papillary muscles were stained positively, i ndicating efficient gene transfer into CM using AAV vectors. These fin dings suggest that AAV vectors are promising for cardiac gene therapy, (C) 1998 Academic Press.