SINGLE CHAIN HIV GP120-CD4 COMPLEX

描述：（改编自申请人的摘要） 包膜糖蛋白gp 120与其细胞表面受体CD 4结合， 引发中和抗体应答的“复合物依赖性”gp 120表位。 这些表位位于结合7个跨膜区的gp 120结构域中。 跨越病毒进入所需的共受体。有证据表明， 我们的前期研究为疫苗的靶点提供了重要的抗原表位 显示：1）共价交联的gp 120-CD 4复合物广泛地诱导 中和针对主要HIV分离株的体液应答。按照规定， 含有构象改变的gp 120的“融合感受态”免疫原 细胞表面受体结合最近显示， 中和针对多种HIV分离株的体液应答， 不同的基因分支这些结果证明了疫苗的发展 提高体液和细胞反应对抗复杂依赖性 表位我们的假设是，这可以通过构建 包含gp 120和CD 4共价连接的单链嵌合分子 通过多肽接头。在本申请中，我们提供了初步证据， 表明这种复合物由编码以下的核苷酸序列表达： 密码子优化的gp 120和可溶性CD 4。为了验证我们的假设，我们 建议进一步开发和表征这些分子，并评估其 在DNA和亚单位疫苗的情况下，免疫原性。工作 我们将以两个具体目标为出发点。第一个将包括生产和 表达可溶性单链CD 4-gp 120的构建体的表征 来自M-嗜性（R5）、双嗜性（R5 X4）和T-嗜性（X4）初级的复合物 病毒。第二个目的是评价单链抗体的免疫原性。 人CD 4转基因小鼠中的CD 4-gpl 20复合物。这项工作将提供新的 与艾滋病毒疫苗具有重大实际和科学相关性的数据 发展

DESCRIPTION: (Adapted from Applicant's Abstract) The binding of the HIV envelope glycoprotein, gpl20, to its cell surface receptor, CD4, exposes novel "complex-dependent" gpl20 epitopes that elicit neutralizing antibody responses. These epitopes are situated in a gpl20 domain that binds 7 transmembrane spanning co-receptors needed for virus entry. Evidence that complex-dependent epitopes might be important vaccine targets was provided by our early studies showing: 1) that covalently crosslinked gp120-CD4 complexes elicit broadly neutralizing humoral responses against primary HIV isolates. In accordance, "fusion competent" immunogens containing gpl20 that is conformationally altered by cell surface receptor binding were recently shown to elicit broadly neutralizing humoral responses against a wide variety of HIV isolates from different genetic clades. These results warrant the development of vaccine strategies to raise humoral and cellular responses against complex dependent epitopes. Our hypothesis is that this can be accomplished by constructing single chain chimeric molecules comprised of gpl20 and CD4 covalently attached by a polypeptide linker. In this application, we provide preliminary evidence showing that such complexes are expressed from nucleotide sequences encoding codon-optimized gpl20 and soluble CD4. In order to evaluate our hypothesis, we propose to further develop and characterize these molecules, and evaluate their immunogenic properties in the contexts of DNA and subunit vaccines. The work will proceed with two specific aims. The first will include the production and characterization of constructs that express soluble, single-chain CD4-gpl20 complexes from M-tropic (R5), dual-tropic (R5X4) and T-tropic (X4) primary viruses. The second Aim will be to evaluate the immunogenicity of single chain CD4-gpl20 complexes in human CD4 transgenic mice. This work should provide new data with significant practical and scientific relevance to HIV vaccine development.