An adenovirus type 5 mutant with the preterminal protein gene deleted efficiently provides helper functions for the production of recombinant adeno-associated virus

Production of recombinant adeno-associated virus (rAAV) requires helper functions that have routinely been provided by infection of the producer cells with adenovirus. Complete removal and/or inactivation of progeny adenovirus, present in such rAAV preparations, presents significant difficulty. Here, we report that an adenovirus type 5 (Ad5) mutant with the preterminal protein (pTP) gene deleted can provide helper function for the growth of rAAV. At high multiplicity, Ad5d1308(Delta pTP) was as efficient as the phenotypically wild-type Ad5d1309 in permitting growth of rAAV. Use of Ad5dl308(Delta pTP), which is incapable of replication in the absence of complementation for pTP, as a helper avoids the need to remove contaminating adenovirus infectious activity by heat inactivation or by purification. Comparison of the transducing ability of rAAV generated with either Ad5dl308(Delta pTP) or Ad5dl309 as a helper demonstrated that the heat inactivation protocol generally used does not remove all of the helper Ad5dl309 function.