Young Kelly R, Smith James M, Ross Ted M
Division of Infectious Diseases, Department of Medicine, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA.
Virology. 2004 Oct 1;327(2):262-72. doi: 10.1016/j.virol.2004.07.009.
An ideal human immunodeficiency virus type-1 (HIV-1) vaccine will most likely need to elicit cross-reactive neutralizing antibodies and a strong cell-mediated immune response against multiple HIV-1 antigens to confer protection against challenge. In this study, DNA vaccines were constructed to express virally regulated human immunodeficiency virus-like particles (VLP) to elicit broad-spectrum immune responses to multiple HIV-1 antigens. VLPs were efficiently produced using sequences encoding gag and pol gene products from an X4 isolate and sequences encoding for tat, rev, vpu, and env from R5 or R5X4 isolates. The integrase, vpr, vif, and nef genes were deleted. In addition, the long terminal repeats (LTRs) were removed and transcription of the VLP insert was driven by the addition of the cytomegalovirus immediate-early (CMV-IE) promoter. A second generation of VLP vaccine plasmids was constructed with mutations engineered into the VLP DNA to produce particles deficient in activities associated with viral reverse transcriptase and protease. Primate cell lines, transiently transfected with DNA, efficiently secreted VLP into the supernatant that banded within a sucrose gradient at densities similar to infectious virions. In addition, these particles incorporated Env on the particle surface that bound soluble human CD4. These VLPs provide a safe and efficient strategy for presenting multiple HIV-1 antigens, expressed from a single insert, to the immune system in a structure that mimics the infectious virion.
一种理想的1型人类免疫缺陷病毒(HIV-1)疫苗很可能需要引发交叉反应性中和抗体以及针对多种HIV-1抗原的强烈细胞介导免疫反应,以提供针对病毒攻击的保护。在本研究中,构建了DNA疫苗以表达病毒调控的类人免疫缺陷病毒颗粒(VLP),从而引发针对多种HIV-1抗原的广谱免疫反应。使用来自X4分离株的编码gag和pol基因产物的序列以及来自R5或R5X4分离株的编码tat、rev、vpu和env的序列高效生产VLP。整合酶、vpr、vif和nef基因被删除。此外,去除了长末端重复序列(LTR),并通过添加巨细胞病毒立即早期(CMV-IE)启动子来驱动VLP插入片段的转录。构建了第二代VLP疫苗质粒,在VLP DNA中引入突变,以产生缺乏与病毒逆转录酶和蛋白酶相关活性的颗粒。用DNA瞬时转染的灵长类细胞系将VLP高效分泌到上清液中,这些VLP在蔗糖梯度中的条带密度与感染性病毒粒子相似。此外,这些颗粒在其表面整合了能结合可溶性人CD4的Env。这些VLP提供了一种安全有效的策略,可将从单个插入片段表达的多种HIV-1抗原以模仿感染性病毒粒子的结构呈递给免疫系统。