title: Single-stranded DNA aptamer RT1t49 inhibits RT polymerase and RNase H functions of HIV type 1, HIV type 2, and SIVCPZ RTs.
abstract: Natural and selected resistance of HIV-1 to current anti-HIV drugs continues to pose serious problems to the development of HIV-1 antivirals. The viral reverse transcriptase (RT) is a proven therapeutic target. Single-stranded RNA and DNA (ssRNA and ssDNA) aptamers have been selected that specifically and potently inhibit RT function. In particular, the ssDNA aptamer RT1t49 was previously selected to recognize the RT from a subtype B strain of HIV-1 and binds with a reported K(d) of 4 nM. In the present work, we show that RT1t49 inhibits recombinant RT cloned from diverse branches of the primate lentiviral family. Aptamer concentrations required for half-maximal inhibition of all HIV-1, HIV-2, and SIV(CPZ) RTs assayed were in the low-to mid-nanomolar range for both polymerase and RNase H activities. Using pre-steady-state and order-of-addition kinetic analyses, we also established that this ssDNA aptamer competes with primer-template for access to RT, and that addition of a nucleoside analog RT inhibitor (NRTI) to the in vitro reaction enhanced the overall effectiveness of both drugs, while nonnucleoside analog RT inhibitors (NNRTIs) exhibited simple additivity. This is the first demonstration of universal inhibition of HIV and SIV(cpz) RTs by a nucleic acid aptamer and supports previous reports suggesting that resistance to RT1t49 may be exceptionally infrequent.
authors.affiliation: Department of Biology, Indiana University, Bloomington, Indiana 47405, USA.
authors.forename: Jay D
authors.initials: JD
authors.lastname: Kissel
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Held
authors.forename: Richard W
authors.initials: RW
authors.lastname: Hardy
authors.forename: Donald H
authors.initials: DH
authors.lastname: Burke
mesh_terms: D000818:Animals; D052157:Aptamers, Nucleotide / Q000235:genetics / Q000494:pharmacology*; D004277:DNA, Single-Stranded / Q000235:genetics / Q000494:pharmacology*; D054303:HIV Reverse Transcriptase / Q000037:antagonists & inhibitors; D015497:HIV-1 / Q000201:enzymology*; D015498:HIV-2 / Q000201:enzymology*; D006801:Humans; D012194:RNA-Directed DNA Polymerase / Q000378:metabolism; D018894:Reverse Transcriptase Inhibitors / Q000494:pharmacology*; D016914:Ribonuclease H / Q000037:antagonists & inhibitors; D015302:Simian Immunodeficiency Virus / Q000201:enzymology*
chemical_list: D052157:Aptamers, Nucleotide; D004277:DNA, Single-Stranded; D018894:Reverse Transcriptase Inhibitors; C072416:reverse transcriptase, Human immunodeficiency virus 2; D054303:HIV Reverse Transcriptase; D012194:RNA-Directed DNA Polymerase; D016914:Ribonuclease H