Kim E Y, Vrang L, Oberg B, Merigan T C
Center for AIDS Research, Stanford University, Stanford, California 94305-5107, USA.
AIDS Res Hum Retroviruses. 2001 Mar 20;17(5):401-7. doi: 10.1089/088922201750102445.
The objective of this work was to test the antiviral activity of a potent nucleoside reverse transcriptase inhibitor, 3'-fluoro-3'-deoxythymidine (FLT), on both a wild-type human immunodeficiency virus (HIV-1) isolate and multidrug-resistant HIV-1 patient isolates. Drug-resistant viral isolates were selected on the basis of four different categories of well-characterized and representative multidrug-resistant mutants. The isolates included three variants containing 151M alone or in combination; three variants containing 215Y and 41L, 67N, 184V, 210W, and 219N in combination; two insertion mutant viruses (69 + EA and 69 + SA); and two deletion mutant viruses (del67NG and del67GS), the latter two groups both also containing other significant mutations. The activity of FLT and AZT against these isolates was determined by drug susceptibility assays and by measuring viral antigen p24 by ELISA. The cytotoxicity of FLT and AZT was assessed in PHA-stimulated PBMCs. Development of resistant mutants under FLT pressure was attempted by passaging HIV-1 isolates in SupT1 cells and stepwise increasing the concentration of FLT. The multidrug-resistant mutant HIV-1 isolates exhibited 7-fold to >100-fold increased resistance to AZT, but showed IC(50) values for FLT of 0.0014-0.0168 microM, which were lower than or similar to that of wild type (0.0075 microM). The cellular cytotoxicities of FLT and AZT fell into a similar range in PBMCs. The development of HIV mutants resistant to FLT appeared to be slower than for other RT inhibitors. HIV isolates with mutations resulting in multidrug resistance had no evidence of resistance to FLT. FLT may be useful in salvage therapies for patients harboring resistant strains and a reassessment of its therapeutic potential seems required.
本研究的目的是测试一种强效核苷类逆转录酶抑制剂3'-氟-3'-脱氧胸苷（FLT）对野生型人类免疫缺陷病毒（HIV-1）分离株和多药耐药HIV-1患者分离株的抗病毒活性。基于四类特征明确且具有代表性的多药耐药突变体选择耐药病毒分离株。这些分离株包括三个单独或组合含有151M的变体；三个组合含有215Y和41L、67N、184V、210W以及219N的变体；两个插入突变病毒（69 + EA和69 + SA）；以及两个缺失突变病毒（del67NG和del67GS），后两组也都含有其他显著突变。通过药物敏感性试验以及用ELISA法检测病毒抗原p24来测定FLT和齐多夫定（AZT）对这些分离株的活性。在PHA刺激的外周血单核细胞（PBMC）中评估FLT和AZT的细胞毒性。通过在SupT1细胞中传代HIV-1分离株并逐步提高FLT浓度，尝试在FLT压力下诱导耐药突变体的产生。多药耐药突变体HIV-1分离株对AZT的耐药性增加了7倍至>100倍，但FLT的半数抑制浓度（IC50）值为0.0014 - 0.0168微摩尔，低于或类似于野生型（0.0075微摩尔）。FLT和AZT在PBMC中的细胞毒性处于相似范围。对FLT耐药的HIV突变体的产生似乎比对其他逆转录酶抑制剂要慢。具有导致多药耐药突变的HIV分离株没有对FLT耐药的证据。FLT可能对携带耐药菌株的患者的挽救治疗有用，似乎需要重新评估其治疗潜力。
