A NEW ANTISENSE TRANSFER-RNA CONSTRUCT FOR THE GENETIC TREATMENT OF HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 INFECTION

Different strategies proposed in the literature to attempt gene therap y of AIDS are based mainly on the intracellular production of RNA and protein therapeutics. This report describes the construction and the a nti-human immunodeficiency virus type 1 (HIV-1) activity of a new type of antisense tRNA directed against a nucleotide region in the first c oding exon of HIV-1 tat (nucleotides 5924 to 5943; Los Alamos data ban k) which is conserved among many HIV-1 clones. The anti-tat antisense sequence was inserted into a tRNA(Pro) backbone by replacement of the anticodon loop, without altering the tRNA canonic tetraloop structure. The antisense tRNA was able to interact effectively with its target i n vitro. Jurkat cells that constitutively expressed the anti-tat tRNA following retroviral vector transduction exhibited significant resista nce to HIV-1 de novo infection. Resistance seemed to correlate with th e level of antisense expression. This is the first time that such a tR NA antisense strategy has been shown to be effective as a genetic trea tment of HIV-1 infection in tissue culture. The construct design propo sed in this report has some intrinsic advantages: the transcript is dr iven by a polymerase III promoter, the short length of the RNA minimiz es effects of intramolecular base pairing that may impair target recog nition, and the antisense RNA has the stability and intracellular fate of a native tRNA molecule.