Helper-dependent (HD) adenoviral (Ad) vectors, in which all viral coding sequences are deleted, have been generated. We show here that intravenous delivery of a mouse EPO (mEPO) expression cassette cloned in an HD vector in immunocompetent mice is effective and long lasting, but not permanent. A precise dose-response relationship between the dose of injected virus and stable EPO serum levels was observed, together with a 100-fold increase in gene expression per infectious particle when compared with a first-generation Ad vector bearing the same cassette. As a direct consequence, therapeutic increases in hematocrit that lasted more than 6 months were achieved with minute amounts of virus, which caused no detectable production of neutralizing antibodies. Intravenous readministration of the HD-mEPO vector in the same mice was as effective as in naive animals without any need for prior immunosuppression. Finally, HD-mEPO injection in subtotally nephrectomized rats improved the anemic status induced by surgery. HD Ad vectors are thus excellent tools for EPO gene therapy.
Prolonged expression and effective readministration of erythropoietin delivered with a fully deleted adenoviral vector
CILIBERTO G.;SAVINO R
2000-01-01
Abstract
Helper-dependent (HD) adenoviral (Ad) vectors, in which all viral coding sequences are deleted, have been generated. We show here that intravenous delivery of a mouse EPO (mEPO) expression cassette cloned in an HD vector in immunocompetent mice is effective and long lasting, but not permanent. A precise dose-response relationship between the dose of injected virus and stable EPO serum levels was observed, together with a 100-fold increase in gene expression per infectious particle when compared with a first-generation Ad vector bearing the same cassette. As a direct consequence, therapeutic increases in hematocrit that lasted more than 6 months were achieved with minute amounts of virus, which caused no detectable production of neutralizing antibodies. Intravenous readministration of the HD-mEPO vector in the same mice was as effective as in naive animals without any need for prior immunosuppression. Finally, HD-mEPO injection in subtotally nephrectomized rats improved the anemic status induced by surgery. HD Ad vectors are thus excellent tools for EPO gene therapy.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.