Universitéé Paris Descartes, EA 3620, AP-HP, Laboratoire de Virologie, Hôpital Necker-Enfants Malades, Paris, France.
J Clin Microbiol. 2010 Oct;48(10):3487-91. doi: 10.1128/JCM.00704-10. Epub 2010 Aug 4.
We used genotypic and phenotypic assays to estimate the frequency of X4/DM viruses in 131 patients infected with non-subtype-B viruses at the time of primary HIV-1 infection (PHI). All patients were enrolled in the French PRIMO Cohort from 1996 to 2007. Most strains belonged to CRF02_AG (51.1%) and subtype A (14.5%). Sixteen viruses (12.2%) were classified as CXCR4 tropic ("X4 strains") by the combined criteria of amino acids 11 and 25 of the V3 loop (11/25) and net charge rules and/or the SVMgeno2pheno(10%) algorithm: 6 strains by the combined genotypic rule, 7 by the SVMgeno2pheno(10%) algorithm, and 3, clustering in subtype D, by both algorithms. However, only one strain (0.8%), belonging to subtype A, was defined as a dual-tropic (DM) virus by the phenotypic assay. The 67 CRF02_AG strains included 2 classified as X4 strains by the combined genotypic rule (3%) and 2 others classified as X4 strains by SVMgeno2pheno(10%) (3%), but none of these 4 strains was an X4 or DM strain according to the phenotypic assay. These results suggest that the cellular virus reservoir was established with X4 strains in very few non-subtype-B-infected patients at the time of PHI. Genotypic predictions can overestimate the proportion of non-subtype-B X4 viruses at PHI.
我们使用基因和表型分析方法来估计在 131 名原发性 HIV-1 感染（PHI）时感染非 B 型病毒的患者中 X4/DM 病毒的频率。所有患者均于 1996 年至 2007 年期间纳入法国 PRIMO 队列。大多数毒株属于 CRF02_AG（51.1%）和 A 亚型（14.5%）。根据 V3 环的氨基酸 11 和 25（11/25）和净电荷规则以及/或 SVMgeno2pheno（10%）算法的综合标准，将 16 种病毒（12.2%）分类为 CXCR4 嗜性（“X4 株”）：6 株通过联合基因型规则，7 株通过 SVMgeno2pheno（10%）算法，3 株，通过两种算法聚类到 D 亚型。然而，只有一株（0.8%）属于 A 亚型的病毒株通过表型分析被定义为双重嗜性（DM）病毒。67 株 CRF02_AG 株中，有 2 株通过联合基因型规则被归类为 X4 株（3%），另有 2 株通过 SVMgeno2pheno（10%）归类为 X4 株（3%），但根据表型分析，这 4 株均不是 X4 株或 DM 株。这些结果表明，在 PHI 时，很少有非 B 型感染患者的细胞病毒库是由 X4 株建立的。基因预测可能高估了 PHI 时非 B 型 X4 病毒的比例。
