HUMAN ANTIBODIES TO INTACT VIRIONS FOR VACCINE RESEARCH

描述（由研究者提供）：由于在天然病毒粒子上表达的HIV-1包膜的固有结构特性，广泛有效的HIV-1疫苗的开发受到限制。HIV-1感染涉及一系列env抗原结构和表位呈递的逐步变化，在此期间病毒展开并将中和表位暴露在靠近靶细胞表面结构的地方。我们提出，免疫系统很难在高阶整合中做出反应，在高阶整合中，两步抗体反应可以修改包膜以暴露，然后二次识别暴露的中和表位。这种更高的整合必须通过疫苗设计强加于免疫系统，因为免疫原必须设计成诱导多种抗体，这些抗体通过“暴露”和“中和”这两个步骤的整合来共同介导病毒中和。体液免疫反应的分析一直受到蛋白质亚基和抗体测定不能准确反映天然病毒粒子上复杂寡聚体结构这一事实的阻碍。为了解决这些问题，确定抗体与天然初级分离病毒粒子反应，并促进抗体特异性和病毒中和分析，我们设计了一种使用来自HIV-1初级分离的整个病毒粒子的检测方法。当检测HIV-1感染者血清中IgG抗体与完整的初级分离病毒粒子反应时，36%的HIV-1感染者捕获病毒（bb0 300pg/ml）。这些个体中只有7%捕获了大量的病毒（50 500pg/ml）。相比之下，一种gp41人单克隆抗体（HMAb） F240捕获了超过2150pg/ml的p24。显然，与初级分离病毒粒子反应的抗体在大多数HIV-1感染者中并不普遍，这可能与血清一般无法中和初级分离病毒有关。我们建议产生HMAb结合完整的初级分离枝A-G，以识别广泛反应性抗体。我们进一步建议在结合反应性抗体后产生针对暴露在病毒粒子上的表位的抗体。从初代分离物中分离和鉴定与完整病毒粒子反应的HMAb，将导致抗原表位和基序的鉴定，用于疫苗目的。

DESCRIPTION (as provided by investigator): Development of a broadly effective HIV-1 vaccine has been limited because of the inherent structural properties the HIV-1 envelope expressed on the native virion. HIV-1 infection involves a series of stepwise changes in env antigenic structures and epitope presentation during which the virus unfolds and exposes neutralizing epitopes in close proximity to the target cell surface structure. We propose, that it is difficult for the immune system to respond in a higher order integration in which a two step antibody response can modify the envelope to expose and then secondarily recognize exposed neutralizing epitopes. This higher integration must be imposed on the immune system through vaccine design in that immunogens must be designed to induce multiple classes of antibodies which together mediate viral neutralization through an integration of these two steps: "exposure" and "neutralization." Analysis of the humoral immune response has been hampered by the fact that protein subunits and antibody assays do not accurately reflect the complex oligomeric structure on native virions. To address these concerns, identify antibodies that react with native primary isolate virions, and facilitate analysis of antibody specificity and viral neutralization, we have designed an assay using whole virions from primary isolates of HIV-1. When serum from HIV-1 infected individuals was tested for IgG antibodies reactive with intact primary isolate virions, 36% of HIV-1 infected individuals captured virus (>300pg/ml). Only 7% of these individuals captured significant quantities of virus (>500pg/ml). By comparison, F240, a gp41 human monoclonal antibody (HMAb) captured more than 2150pg/ml of p24. Clearly antibodies reactive with primary isolate virions are not prevalent in the majority of HIV-1 infected individuals which may be related to the general inability of sera to neutralize primary isolates. We propose to generate HMAb which bind to intact primary isolates of clades A-G to identify broadly reactive antibodies. We further propose to generate antibodies to epitopes exposed on virions following binding of reactive antibodies. Isolation and characterization of HMAb reactive with intact virions from primary isolates should lead to the identification of antigenic epitopes and motifs for vaccine purposes.