Genetic Susceptibility of Antibody-dependent Enhancement of Flaviviruses

黄病毒抗体依赖性增强的遗传易感性

• 批准号: 9815044
• 负责人: Jean Kyou Lim
• 金额: $ 25.36万
• 依托单位: ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-06-05 至 2021-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9815044
• 关键词: Affinity; Alleles; Amino Acids; Antibodies; Antibody-Dependent Enhancement; Arginine; Attention; Binding; CRISPR/Cas technology; Cell Line; Cells; Characteristics; Congenital Abnormality; Cross Infection; Data; Dengue Virus; Disease; Flavivirus; Flavivirus Infections; Genes; Genetic Polymorphism; Genetic Predisposition to Disease; Genotype; Human; Human Cloning; IgG Receptors; IgG1; IgG2; IgG3; IgG4; Immunoglobulin G; In Vitro; Individual; Infection; International; K-562; K562 Cells; Mediating; Molecular; Monoclonal Antibodies; Placenta; Positioning Attribute; Risk Factors; Serotyping; Severity of illness; Single Nucleotide Polymorphism; Testing; Variant; Viral Load result; Virus Diseases; ZIKV infection; Zika Virus; base; epidemiologic data; high risk; macrophage; monocyte; mosquito-borne; receptor; repaired

PROJECT SUMMARY: Antibody-dependent enhancement (ADE) is a phenomenon characteristic of some flavivirus infections and best known to occur between the four DENV serotypes in humans, but may also occur between sequential DENV, then ZIKV infections (or vice versa). ADE occurs when subneutralizing levels of antibodies raised against one flavivirus infection cross-react to enhance a closely related flavivirus infection. ADE is entirely dependent on the binding of IgG antibodies to FcRs found on susceptible cells, such as monocytes/macrophages. In humans, there is a nonsynonymous polymorphism that occurs in the FcRIIA gene (rs1801274) that leads to an arginine (Arg) to histadine (His) change at position 131 that has been shown to alter the affinity of this receptor for IgG antibodies. We hypothesize that individuals homozygous for the FcRIIA encoding for the high affinity His allele are at higher risk for developing ADE of flaviviruses than individuals homozygous for the low affinity Arg allele. In this application, we will test this using K562 cells homozygous for the Arg131 or the His131 allele as well as primary human monocytes stratified based on genotype to test how this SNP impacts ADE of flaviviruses in vitro (Aim 1). Using two flavivirus-specific monoclonal antibody clones that we found to enhance flavivirus infection in K562 cells, we will generate IgG subclass switch variants (IgG1, IgG2, IgG3, or IgG4) to determine the relative contribution of each IgG subclass in mediating ADE of flaviviruses (Aim 2).

项目概要： 抗体依赖性增强（ADE）是某些黄病毒感染的特征现象，最好 已知发生在人类的四种 DENV 血清型之间，但也可能发生在连续的 DENV 之间， 当针对一种病毒的抗体水平低于中和水平时，就会发生 ZIKV 感染（反之亦然）。 黄病毒感染的交叉反应增强密切相关的黄病毒感染完全依赖于黄病毒感染。 IgG 抗体与易感细胞（例如单核细胞/巨噬细胞）上的 FcR 结合。 在人类中，FcRIIA 基因 (rs1801274) 中存在非同义多态性，导致 第 131 位精氨酸 (Arg) 变为组氨酸 (His)，这已被证明可以改变该亲和力 我们勇敢地认为，FcRIIA 编码高的纯合个体。 与低亲和力纯合子相比，His 等位基因发生黄病毒 ADE 的风险更高 在此应用中，我们将使用 Arg131 纯合的 K562 细胞进行测试。 His131 等位基因以及原代人类单核细胞根据基因型分层，以测试该 SNP 如何影响 使用我们发现的两种黄病毒特异性单克隆抗体克隆进行体外黄病毒 ADE（目标 1）。 增强黄病毒在 K562 细胞中的感染，我们将生成 IgG 亚类转换变体（IgG1、IgG2、IgG3 或 IgG4) 以确定每个 IgG 亚类在介导黄病毒 ADE 中的相对贡献（目标 2）。