REPLICATION-DEFECTIVE ADENOVIRUS TYPE-5 AS AN IN-VITRO AND IN-VIVO GENE-TRANSFER VECTOR IN CHICKENS

The capacity of E1A gene-deleted and thus replication-defective adenov irus type 5 (Ad5) to transduce foreign genes in chicken embryo fibrobl asts (CEF) as well as in chickens was investigated. The lacZ and lucif erase genes were successfully transduced in CEF by replication-defecti ve Ad5, demonstrating that these cells possess receptor(s) for binding and penetration of Ad5. A single intramuscular inoculation of Ad-gD, a replication-defective Ad5 harbouring the gD gene of pseudorabies vir us, in adult and 1-day-old chickens led to the production of very high titres of specific antibodies. These gD-specific antibodies persisted for at least 56 days. These results demonstrate that replication-defe ctive Ad5, despite its mammalian origin and the deletion of the E1A ge ne, is a good candidate for developing non-spreading vaccines in poult ry.