The identification of the disulfide bonds in HIV gp120 whose reduction is required for cell entry and their manipulation for immunogen design

人类免疫缺陷病毒（HIV）感染是获得性免疫缺陷综合征（AIDS）的原因，也是全世界死亡的主要原因。尽管进行了广泛的研究工作，但有效疫苗的研究尚未成功，仍需要对新的候选疫苗进行评估。病毒通过病毒包膜糖蛋白和靶细胞表面之间的相互作用进入细胞，特别是称为CD4和CCR的两种细胞表面分子。在这些分子之间接触之后，发生许多生化步骤，导致病毒穿透细胞开始感染。所需的生化步骤的确切性质仍然是一个研究问题，但如果它们被清楚地识别出来，它们可能在新的潜在疫苗的设计中有用。我们发现了一个特殊的生化变化，二硫键还原，这似乎是重要的病毒进入。如果这一步被抑制，病毒感染就不会发生，这表明这是进入过程中的关键中间阶段。我们希望使用一种新技术，包括非常灵敏的质谱法，以确定在感染过程中被还原的病毒包膜糖蛋白的特定二硫键，以便提供比目前情况更高水平的关于进入过程的透明度。当特定的二硫键已知时，我们将制造一些还原的蛋白质，并将其性质与正常的未还原形式进行比较。我们还将测试这种中间蛋白质是否是HIV感染过程的关键部分，方法是用它来产生抗体，这些抗体将被测试，看看它们是否能预防感染。抗体是宿主对感染的反应，它与还原的蛋白质结合并停止其功能，这将证明还原的蛋白质可以被认为是有效的疫苗候选物。

Infection by the Human immunodeficiency virus (HIV) is the cause of acquired immunodeficiency syndrome (AIDS) and is a major cause of death worldwide. Despite extensive research efforts the search for an effective vaccine has not yet been successful and there is a continued need for new candidates to be assessed. The virus enters the cell via interaction between the virus envelope glycoprotein and the target cell surface, in particular two cell surface molecules called CD4 and CCR. Following contact between these molecules a number of biochemical steps occur which result in the virus penetrating the cell to start the infection. The precise nature of the biochemical steps required is still a matter of research but if they are identified clearly they may be useful in the design of the new potential vaccines. We have discovered one particular biochemical change, disulfide bond reduction, which appears to be important for virus entry. If this step is inhibited virus infection cannot occur suggesting it is a key intermediate stage in the entry process. We want to use a new technology involving very sensitive mass spectrometry to identify the particular disulfide bonds of the virus envelope glycoprotein that are reduced during the infection process in order to provide a greater level of clarity about the entry process than is currently the case. When the particular disulfide bonds are known we will make some of the reduced protein and compare its properties to the normal, unreduced form. We will also test if this intermediate protein is a key part of the HIV infection process by using it to generate antibodies which will be tested to see if they prevent infection. Antibodies, the host's response to infection, which bind to the reduced protein and stop its function will prove that the reduced protein can be considered a valid vaccine candidate.