Sabariegos Rosario, Giménez-Barcons Mireia, Tàpia Natalia, Clotet Bonaventura, Martínez Miguel Angel
Fundació irsiCaixa, Laboratori de Retrovirologia, Hospital Universitari Germans Trias i Pujol, Ctra del Canyet s/n, 08916 Badalona, Spain.
J Virol. 2006 Jan;80(2):571-7. doi: 10.1128/JVI.80.2.571-577.2006.
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.
靶向病毒或细胞基因的小干扰RNA（siRNA）能够有效抑制1型人类免疫缺陷病毒（HIV-1）的复制。然而，被靶向基因中突变的出现可能导致病毒迅速逃离siRNA的作用。在此，我们通过在一种有效siRNA靶向的所有19个HIV-1残基中系统性地引入单核苷酸替换来模拟病毒逃逸。我们发现，所有经测试的突变病毒在siRNA存在的情况下比在野生型病毒存在的情况下复制得更好。在测试的16个位置中，有10个位置（第4至11位、第14位和第15位）的单碱基替换完全消除了siRNA的抗病毒活性（在探索的19个位置中有3个位置的替换产生了无活力的病毒）。除了在第12位观察到的替换外，5'端或3'端（第1至3位、第16位和第18位）的替换更能被RNA干扰机制耐受，并且只是部分影响siRNA的抑制作用。我们的结果表明，siRNA实现最佳的HIV-1基因沉默需要在大部分靶序列内具有完全同源性，并且在5'端和3'端只有少数几个位置的替换能被部分耐受。
