EXPRESSION OF HIV-2 ENV GENE PRODUCTS IN E.COLI

人类免疫缺陷病毒2型(HIV-2)，西非的对应物 与获得性免疫缺陷综合征(AIDS)病毒有关，但 与HIV-1截然不同。HIV-2 NIH-Z基因组约为9.4 Kb长，env基因长约2.7kb，编码一个包膜 蛋白质由856个氨基酸组成。Gpl60被膜蛋白成熟为一种 120kD的外膜糖蛋白(Gpl2O)和35kD的跨膜蛋白 (Gp35)。HIV-2 NIH-Z株的gpl2O和gp35囊膜蛋白显示约32% 分别与人类嗜T淋巴细胞病毒有39%的同源性， HIV-1IIIB型(HTLV-IIIB)毒株。这个项目的主要目标是 是(1)开发一种用于准确检测抗体的诊断抗原 在所有受感染的人血清中检测到HIV-2，以及(2)使用 细菌表达的HIV-2 env基因产物在某些疫苗中的应用。 我们已经将HIV-2 NIH-Z分离株的env基因表达为5个 在大肠杆菌中重叠的片段。环境蛋白开放阅读框(ORF)为 最初表达为12个氨基末端之间的三方融合 E. 受lambda PL启动子转录控制的大肠杆菌 表达载体pWS50。融合的0-半乳糖苷酶部分 然后在DNA水平上通过生成内框来删除蛋白质 翻译停顿或翻译移帧突变。其中一个兽人 跨越HIV-2 env基因的536至705个氨基酸残基 指导合成具有血清学特异性的20kD蛋白质 用于鉴定HIV-2抗体。这种抗原性蛋白是在 含量约占细胞总蛋白的5%。-没有重大意义 免疫交叉反应观察与HIV-1阳性血清或 与正常对照血清进行免疫印迹试验，粗制制剂 这种蛋白质。目前正在进行免疫学表征方面的工作 其余四个HIV-2包膜ORF的基因产物。

Human immunodeficiency virus, type-2 (HIV-2), the West African counterpart of the acquired immunodeficiency syndrome (AIDS) virus, is related to, but is quite distinct from HIV-1. The HIV-2 NIH-Z genome is approximately 9.4 kb long with an env gene of about 2.7 kb which codes for an envelope protein of 856 amino acids. The gpl6O envelope protein is matured into a 120 Kd exterior glycoprotein (gpl2O) and a transmembrane protein of 35 Kd (gp35). The gpl2O and gp35 envelope proteins of HIV-2 NIH-Z show about 32% and 39% homology, respectively, with the human T-lymphotropic virus, type-IIIB (HTLV-IIIB) strain of HIV-1. The chief objectives of this project are (1) to develop a diagnostic antigen for accurately detecting antibodies to HIV-2 in all infected human sera and (2) to use the bacterially-expressed HIV-2 env gene products in some vaccine applications. We have expressed the env gene of the NIH-Z isolate of HIV-2 as five overlapping fragments in E. coli. The env open reading frames (ORFS) were initially expressed as tripartite fusions in between the 12 amino-terminal codons of the lambda cII gene and the lacZ (Beta-galactosidase) gene of E. coli that are under the transcriptional control of the lambda PL promoter of the expression plasmid pWS50. The 0-galactosidase portion of the fusion protein was then deleted at the DNA level by generating in-frame translational stops or translational frame-shift mutations. One of the ORFs spanning the amino acid residues 536 through 705 of the HIV-2 env gene directed the synthesis of a 20 Kd protein that was serologically specific for identifying antibodies to HIV-2. This antigenic protein is produced at levels approximately 5% of the total cellular proteins. -No significant immunological cross-reactivity was observed with HIV-1-positive sera or with normal control sera in immmunoblot assays with a crude preparation of this protein. Work is now in progress on the immunological characterization of the gene products of the remaining four HIV-2 env ORFS.