The wild-type Rep proteins of adeno-associated virus type 2 (AAV) have been demonstrated in tissue culture to inhibit the replication of HIV-1, the etiological agent of AIDS. Unfortunately, their potential as a therapeutic agent for AIDS is limited because they also appear to block cell division. Several groups have tried and failed to produce cell lines producing high levels of Rep proteins, although we have achieved high levels in transient expression assays in cells transfected with a plasmid expressing the rep gene from the long terminal repeat promoter of HIV-1 (HIV-LTR). Our objective is to create a mutant Rep protein which can block HIV-1 replication without blocking cell division. We have made a series of mutant rep genes expressed from the HIV-LTR. Our collaborators at the New Jersey Center for Advanced Biotechnology and Medicine have already tested several of these mutants for their ability to block HIV-1 replication. Plasmids containing the mutant rep genes are co-transfected with an infectious proviral clone of HIV-1 into human cells and the cells and culture supernatants are assayed for reverse transcriptase activity, HIV-1 RNA and for HIV-1 gag protein. We have identified several portions of the Rep proteins which are important for this inhibition. Several of these mutants inhibit HIV-1 better than the wild-type proteins. If we can identify a mutant Rep protein that blocks HIV-1 production without blocking cell division then we would have the basis for a novel treatment for AIDS. If Rep proteins truly block cell division then they may also be developed into a treatment for cancer. We will continue to produce and test mutant Rep proteins for HIV- inhibition. We will be concurrently attempting to produce cell lines making these mutant proteins. This will allow us to determine which parts of the Rep proteins are involved in the putative cell division block.
