Impact of HLA-B*81-associated mutations in HIV-1 Gag on viral replication capacity.
Impact of HLA-B*81-associated mutations in HIV-1 Gag on viral replication capacity.
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HIV-1 Gag 中 HLA-B*81 相关突变对病毒复制能力的影响。
DOI：
10.1128/jvi.06682-11
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发表时间：
2012
影响因子：
5.4
通讯作者：
Ndung'u,Thumbi
中科院分区：
文献类型：
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作者：
Wright,JaclynK;Naidoo,VanessaL;Brumme,ZabrinaL;Prince,JessicaL;Claiborne,DanielT;Goulder,PhilipJR;Brockman,MarkA;Hunter,Eric;Ndung'u,Thumbi
在GAG中选择的免疫逃逸突变导致的HIV-1减弱可能有助于表达某些HLAI类等位基因的HIV-1感染者的疾病进展缓慢。我们先前的研究表明，保护性等位基因HLA-B*81和人类白细胞抗原B*81选择的Gag T186S突变与编码HIV-1 C亚型慢性感染者Gag蛋白水解酶的重组病毒的病毒复制能力降低密切相关。在本研究中，我们直接测试了该突变对病毒复制能力的影响。此外，我们还研究了各种基因多态的潜在代偿效应，包括与T186S突变显著相关的其他与HLA-B*81相关的突变。通过定点突变，将突变引入参考B亚型骨干和患者衍生的B和C亚型骨干中的C亚型序列。用绿色荧光蛋白报告T细胞系的流式细胞术或通过测定培养上清液中HIV-1逆转录酶活性来检测突变型和野生型病毒的指数期生长。将T186S突变单独工程到所有患者来源的C亚型序列中都无法产生具有复制能力的病毒，而在B亚型序列中，T186S突变导致复制能力受损。只有T186S突变和T190I突变一起产生了所有被测试的病毒骨架的复制能力强的病毒；然而，这些结构的复制比野生型慢，这表明只有部分补偿是由T190I突变介导的。编码T186S突变和其他假定的代偿突变的构建体减弱或有缺陷。这些结果表明，T186S突变对HIV-1 C亚型复制是有害的，可能需要复杂的代偿途径，这可能有助于与HLA-B*81相关的临床益处。
HIV-1 attenuation resulting from immune escape mutations selected in Gag may contribute to slower disease progression in HIV-1-infected individuals expressing certain HLA class I alleles. We previously showed that the protective allele HLA-B*81 and the HLA-B*81-selected Gag T186S mutation are strongly associated with a lower viral replication capacity of recombinant viruses encoding Gag-protease derived from individuals chronically infected with HIV-1 subtype C. In the present study, we directly tested the effect of this mutation on viral replication capacity. In addition, we investigated potential compensatory effects of various polymorphisms, including other HLA-B*81-associated mutations that significantly covary with the T186S mutation. Mutations were introduced into a reference subtype B backbone and into patient-derived subtype C sequences in subtype B and C backbones by site-directed mutagenesis. The exponential-phase growth of mutant and wild-type viruses was assayed by flow cytometry of a green fluorescent protein reporter T cell line or by measurement of HIV-1 reverse transcriptase activity in culture supernatants. Engineering of the T186S mutation alone into all patient-derived subtype C sequences failed to yield replication-competent viruses, while in the subtype B sequence, the T186S mutation resulted in impaired replication capacity. Only the T186S mutation in combination with the T190I mutation yielded replication-competent viruses for all virus backbones tested; however, these constructs replicated slower than the wild type, suggesting that only partial compensation is mediated by the T190I mutation. Constructs encoding the T186S mutation in combination with other putative compensatory mutations were attenuated or defective. These results suggest that the T186S mutation is deleterious to HIV-1 subtype C replication and likely requires complex compensatory pathways, which may contribute to the clinical benefit associated with HLA-B*81.