Frobert E, Ooka T, Cortay J C, Lina B, Thouvenot D, Morfin F
Laboratoire de Virologie, Hospices Civils de Lyon, Domaine Rockefeller, 8 avenue Rockefeller, 69373 Lyon cedex 08, France.
Antimicrob Agents Chemother. 2005 Mar;49(3):1055-9. doi: 10.1128/AAC.49.3.1055-1059.2005.
Mutations in the thymidine kinase (TK) gene of herpes simplex virus (HSV) may confer resistance to acyclovir (ACV). Because of the high genetic polymorphism of this gene, discriminating between mutations related to resistance and mutations related to gene polymorphism can be difficult, especially when no sensitive strain has been previously isolated from the same patient. To assess the role of the mutations located at codons 51, 77, 83, and 175, previously detected in HSV-1 clinical isolates (F. Morfin, G. Souillet, K. Bilger, T. Ooka, M. Aymard, and D. Thouvenot, J. Infect. Dis. 182:290-293, 2000), in the acquisition of resistance to ACV, four mutants with site-directed mutations at these respective codons were constructed. The enzymatic activity of the proteins, produced using both a reticulocyte lysate system and a bacterial system, was evaluated using [(3)H]thymidine as substrate. This site-directed mutagenesis revealed that mutations at codons 51, 83, and 175 induce a loss of HSV-1 TK activity and are thus clearly involved in the acquisition of resistance to ACV. On the other hand, the mutation at codon 77 does not affect enzyme activity.
单纯疱疹病毒（HSV）胸苷激酶（TK）基因的突变可能会使其对阿昔洛韦（ACV）产生耐药性。由于该基因具有高度的遗传多态性，区分与耐药相关的突变和与基因多态性相关的突变可能会很困难，尤其是当之前未从同一患者中分离出敏感菌株时。为了评估先前在HSV-1临床分离株中检测到的位于第51、77、83和175密码子处的突变（F. Morfin、G. Souillet、K. Bilger、T. Ooka、M. Aymard和D. Thouvenot，《传染病杂志》182:290 - 293，2000年）在获得对ACV耐药性中的作用，构建了在这些相应密码子处有定点突变的四个突变体。使用网织红细胞裂解物系统和细菌系统产生的蛋白质的酶活性，以[³H]胸苷为底物进行评估。这种定点诱变表明，第51、83和175密码子处的突变会导致HSV-1 TK活性丧失，因此显然与获得对ACV的耐药性有关。另一方面，第77密码子处的突变不影响酶活性。
