Prolonged expression and effective readministration of erythropoietin delivered with a fully deleted adenoviral vector.
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.
Maione
D
D
Department of Genetics, IRBM P. Angeletti, Pomezia, Italy.
Wiznerowicz
M
M
Delmastro
P
P
Cortese
R
R
Ciliberto
G
G
La Monica
N
N
Savino
R
R
D000256:Adenoviridae / Q000235:genetics*; D000818:Animals; D000917:Antibody Formation; D004921:Erythropoietin / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D005260:Female; D018014:Gene Transfer Techniques; D005822:Genetic Vectors; D006400:Hematocrit; D007275:Injections, Intravenous; D051379:Mice; D008807:Mice, Inbred BALB C; D008811:Mice, Inbred DBA; D009392:Nephrectomy; D051381:Rats; D017207:Rats, Sprague-Dawley; D017384:Sequence Deletion; D013045:Species Specificity; D013997:Time Factors
D004921:Erythropoietin