van Harmelen J, Wood R, Lambrick M, Rybicki E P, Williamson A L, Williamson C
Department of Medical Microbiology, University of Cape Town, Observatory, South Africa.
AIDS. 1997 Jan;11(1):81-7. doi: 10.1097/00002030-199701000-00012.
To determine HIV-1 env and gag subtypes in male homosexual and heterosexual populations in Cape Town, South Africa.
DNA was isolated from blood originating from 61 patients attending local clinics. Samples were divided according to presumed mode of transmission: male homosexual (n = 26), heterosexual/vertical (n = 32), blood transfusion (n = 1) and unknown (n = 2).
Proviral HIV-1 DNA was subtyped by heteroduplex mobility assay (HMA) based on the 799 base-pair V3-V5 region of the env gene (n = 47) or by sequence analysis of the p17 region of the gag gene (n = 33), or both. For HMA, reference plasmids were constructed containing the V1-V5 env region sequences (1.2-kb) representative of local subtypes. Subtype designation of reference subtypes was confirmed by sequence analysis of the V3-loop region.
Analysis of the partial gag sequences and HMA of the V3-V5 env region identified three subtypes: B, C and D. A fourth env subtype, subtype E, was also identified by HMA. Subtypes were found to segregate according to mode of transmission, with subtype B viruses found in 96% (25 out of 26) of the male homosexual group and subtype C viruses found in 81% (26 out of 32) of the heterosexual/vertical transmission group. Subtype B viruses were also found in four heterosexual patients, one patient infected by blood transfusion and in two patients with unknown mode of transmission. Subtype D viruses were found in one male homosexual patient and one heterosexual patient. A subtype E virus was identified in a heterosexual patient. No discrepancy was found in subtype designation in samples analysed in both between the gag and env regions (n = 19).
Subtype B viruses were associated with male homosexual transmission and subtype C viruses with heterosexual transmission, suggesting two independent epidemics. This data may have implications in the selection of appropriate vaccines for different risk groups in the country.
确定南非开普敦男性同性恋和异性恋人群中的HIV-1 env和gag亚型。
从当地诊所61名患者的血液中分离DNA。样本根据推测的传播方式进行划分：男性同性恋（n = 26）、异性恋/垂直传播（n = 32）、输血（n = 1）和不明（n = 2）。
基于env基因799个碱基对的V3-V5区域（n = 47），通过异源双链迁移率分析（HMA）对前病毒HIV-1 DNA进行亚型分型，或通过对gag基因p17区域进行序列分析（n = 33），或两者兼用。对于HMA，构建包含代表当地亚型的V1-V5 env区域序列（1.2 kb）的参考质粒。通过对V3环区域的序列分析确认参考亚型的亚型指定。
对部分gag序列和V3-V5 env区域的HMA分析确定了三种亚型：B、C和D。通过HMA还鉴定出第四种env亚型E。发现亚型根据传播方式进行分离，在男性同性恋组的96%（26例中的25例）中发现B亚型病毒，在异性恋/垂直传播组的81%（32例中的26例）中发现C亚型病毒。在4名异性恋患者、1名输血感染患者和2名传播方式不明的患者中也发现了B亚型病毒。在1名男性同性恋患者和1名异性恋患者中发现了D亚型病毒。在1名异性恋患者中鉴定出1株E亚型病毒。在同时分析gag和env区域的样本（n = 19）中，亚型指定未发现差异。
B亚型病毒与男性同性恋传播相关，C亚型病毒与异性恋传播相关，提示存在两种独立的流行情况。该数据可能对该国不同风险群体选择合适的疫苗有影响。
