title: Sequence homology required by human immunodeficiency virus type 1 to escape from short interfering RNAs.
abstract: Short interfering RNAs (siRNAs) targeting viral or cellular genes can efficiently inhibit human immunodeficiency virus type 1 (HIV-1) replication. Nevertheless, the emergence of mutations in the gene being targeted could lead to the rapid escape from the siRNA. Here, we simulate viral escape by systematically introducing single-nucleotide substitutions in all 19 HIV-1 residues targeted by an effective siRNA. We found that all mutant viruses that were tested replicated better in the presence of the siRNA than in the presence of the wild-type virus. The antiviral activity of the siRNA was completely abolished by single substitutions in 10 (positions 4 to 11, 14, and 15) out of 16 positions tested (substitution at 3 of the 19 positions explored rendered nonviable viruses). With the exception of the substitution observed at position 12, substitutions at either the 5' end or the 3' end (positions 1 to 3, 16, and 18) were better tolerated by the RNA interference machinery and only in part affected siRNA inhibition. Our results show that optimal HIV-1 gene silencing by siRNA requires a complete homology within most of the target sequence and that substitutions at only a few positions at the 5' and 3' ends are partially tolerated.
authors.affiliation: Fundació irsiCaixa, Laboratori de Retrovirologia, Hospital Universitari Germans Trias i Pujol, Ctra del Canyet s/n, 08916 Badalona, Spain.
authors.forename: Rosario
authors.initials: R
authors.lastname: Sabariegos
authors.forename: Mireia
authors.initials: M
authors.lastname: Giménez-Barcons
authors.forename: Natalia
authors.initials: N
authors.lastname: Tàpia
authors.forename: Bonaventura
authors.initials: B
authors.lastname: Clotet
authors.forename: Miguel Angel
authors.initials: MA
authors.lastname: Martínez
mesh_terms: D019943:Amino Acid Substitution; D020868:Gene Silencing; D015658:HIV Infections / Q000628:therapy; D054303:HIV Reverse Transcriptase / Q000235:genetics; D015497:HIV-1 / Q000235:genetics / Q000502:physiology*; D009154:Mutation; D034741:RNA, Small Interfering / Q000235:genetics*; D014779:Virus Replication
chemical_list: D034741:RNA, Small Interfering; D054303:HIV Reverse Transcriptase