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INCREASE/gp120 IMMUNOGENICITY/LINKED ALPHA-GAL EPITOPES

增加/gp120 免疫原性/相连的 ALPHA-GAL 表位

基本信息

批准号：
6952812
负责人：
URI GALILI GALILI
金额：
$ 24.31万
依托单位：
UNIV OF MASSACHUSETTS MED SCH WORCESTER
依托单位国家：
美国
项目类别：
财政年份：
2004
资助国家：
美国
起止时间：
2004-09-30 至 2006-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/6952812
关键词：
AIDS vaccines HIV envelope protein gp120 antigen presentation galactosides immune response laboratory mouse protein engineering protein purification vaccine development vaccine evaluation

项目摘要

DESCRIPTION (provided by applicant): The overall objective of this project is to develop a novel type of gp120 vaccine that exploits the natural anti-Gal antibody (Ab) as a natural adjuvant effectively targeting gp120 to antigen presenting cells (APC). This vaccine is comprised of gp120 engineered to express multiple alpha-gal epitopes (Galphal/alpha1-3 Galbeta1-4GlcNAc-R) on the many N(asparagine)-linked carbohydrate chains of this glycoprotein. HIV vaccines have to be effectively targeted to APC in order to elicit a protective immune response. Changing carbohydrates on gp120 to alpha-gal epitopes will significantly increase uptake of antigen by APC by both eliminating the negative charge of gp120 and by targeting gp120 to APC Fcgamma receptors. We propose to convert the multiple sialic acid (SA) units on recombinant gp120 produced in CHO cells, into alpha-gal epitopes (referred to as gpl20(gal) by the use of recombinant alpha1,3 galactosyltransferase (alpha 1,3 GT) that we produce. Vaccination with gpl20/alpha/gal is likely to result in in situ formation of immune complexes with the natural anti-Gal Ab, the most abundant Ab in humans constituting 1% of circulating IgG. We hypothesize that the immune complexes formed between gpl20/alpha/gal and anti-Gal target the vaccinating molecules to APC, since the Fc portion of the complexed anti-Gal IgG binds to Fcgamma receptors on APC. This results in increased processing and presentation (including cross presentation) of gp120 peptides for effective activation of CD4+ and CD8+ T cells. Our aim is to obtain a proof of principle for the increased immunogenicity of gp120(gal in comparison with that of gp120 in an experimental animal model system of (l,3GT knockout mice which simulates pertinent immune parameters in humans. Specifically, we propose: 1. To process and purify large amounts of gp120/alpha/gal for use as vaccine. 2. To demonstrate the superiority of the gp120/alpha/gal vaccine for increasing humoral and cellular immune response in mice in comparison with gp120 vaccine. If we find, in this preliminary project, that gp120/alpha/gal vaccine is significantly more immunogenic than gp120, we will, in future studies, increase the range of antigenic targets by fusing gp120 with p18 or p24 of HIV. We will then also collaborate with a group studying immune responses in monkeys to determine the efficacy of this vaccine in a primate model.

描述（由申请人提供）：本项目的总体目标是开发一种新型gp 120疫苗，该疫苗利用天然抗Gal抗体（Ab）作为天然佐剂，有效靶向gp 120至抗原呈递细胞（APC）。该疫苗由gp 120组成，该gp 120经工程改造以在该糖蛋白的许多N（天冬酰胺）连接的碳水化合物链上表达多个α-gal表位（Glucoal/α 1 -3 Galbeta 1 -4GlcNAc-R）。HIV疫苗必须有效地靶向APC以引起保护性免疫应答。将gp 120上的碳水化合物改变为α-gal表位将通过消除gp 120的负电荷和通过将gp 120靶向APC Fc γ受体来显著增加APC对抗原的摄取。我们建议通过使用我们生产的重组α 1，3半乳糖基转移酶（α 1，3 GT）将CHO细胞中产生的重组gp 120上的多个唾液酸（SA）单位转化为α-gal表位（称为gp 120（gal））。用gpl 20/a/gal接种可能导致与天然抗Gal Ab原位形成免疫复合物，天然抗Gal Ab是人体中最丰富的Ab，构成循环IgG的1%。我们假设gpl 20/a/gal和抗Gal之间形成的免疫复合物将疫苗接种分子靶向APC，因为复合的抗Gal IgG的Fc部分结合APC上的Fc γ受体。这导致gp 120肽的加工和呈递（包括交叉呈递）增加，以有效活化CD 4+和CD 8 + T细胞。我们的目的是在模拟人体相关免疫参数的β 1，3-GT敲除小鼠的实验动物模型系统中，与gp 120相比，获得gp 120 β 1的免疫原性增加的原理证明。具体而言，我们建议：1。加工和纯化大量gp 120/alpha/gal用作疫苗。2.证明与gp 120疫苗相比，gp 120/alpha/gal疫苗在增加小鼠体液和细胞免疫应答方面的优效性。如果我们在这个初步项目中发现gp 120/alpha/gal疫苗比gp 120具有更强的免疫原性，我们将在未来的研究中通过将gp 120与HIV的p18或p24融合来增加抗原靶点的范围。然后，我们还将与一个研究猴子免疫反应的小组合作，以确定这种疫苗在灵长类动物模型中的有效性。