RECOMBINANT ANTIBODIES FOR INFANT PROTECTION

用于婴儿保护的重组抗体

• 批准号: 2887125
• 负责人: Sherie L Morrison
• 金额: $ 24.62万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-09-30 至 2000-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2887125
• 关键词: Escherichia coli; Escherichia coli infections; agglutination reaction; antibacterial antibody; antibody receptor; cell adhesion; cell mediated cytotoxicity; chickens; complement; enterotoxins; genetically modified animals; immunoglobulin A; immunoglobulin G; intravenous administration; laboratory mouse; microorganism disease chemotherapy; monoclonal antibody; mucosal immunity; neutralizing antibody; nonhuman therapy evaluation; oral administration; phagocytes; pharmacokinetics; recombinant proteins; secretory protein

In the current grant we propose to expand our studies of genetically engineered antibody molecules, focusing our attention on the goal of providing more effective immunity to the fetus and neonate. In one series of experiments we will identify and produce antibodies with the optimal combination of functional properties to provide protection at the mucosal surface following oral administration or transport from the mother via the placenta or mammary gland. Human IgA is the antibody normally found in the exocrine secretions. IgA, domain exchange proteins between human IgA and IgG, and site directed mutants will be characterized with respect to their stability, half-life, and biodistribution when administered either orally or intravenously. They will be characterized with respect to their ability to bind and be transported by the epithelial receptors. They also will be assessed for their ability to activate the complement cascade and to bind to Fc receptors specific for either IgG or IgA on phagocytes. We will also attempt to develop a cell which expresses antibody with attached secretory component (SC). One goal will be to produce recombinant antibodies which provide treatment or protection against enteric infections, a significant health problem world wide. We will assay the most promising recombinant antibodies in the suckling mouse model for enterotoxigenic Escherichia coli (ETEC) using antibodies specific for the F41 antigen. Antibodies to F4l have proven efficacy and recombinant antibodies administered orally to pups or intravenously to dams will be assessed for their ability to prevent lethality and to decrease colonization. In vitro assays of adherence, agglutination and complement mediated cytotoxicity will address the mechanism(s) of protection. If recombinant antibodies are to be broadly applied, an inexpensive expression system must be available and we will focus our attention on the development of the transgenic chicken as such an expression system. The chicken is inexpensive to maintain and targets large amounts of antibody to the egg yolk. Intravenous injection of iodinated antibodies into laying hens will be used to determine which antibodies will be transported to the yolk. Vectors tested for Ig expression using chicken lymphoid cell lines will be transfected into Stage X blastoderm cells and these transfected cells used to make chimeric embryos. The resulting chickens will be tested for the presence of chimeric lg in their serum and in the eggs of laying hens.

在当前的拨款中，我们建议扩大我们的遗传学研究 工程抗体分子，将我们的注意力集中在以下目标上 为胎儿和新生儿提供更有效的免疫力。在一个系列中 通过实验，我们将鉴定并生产具有最佳性能的抗体 功能特性的组合，为粘膜提供保护 口服给药或通过母体运输后的表面 胎盘或乳腺。人类 IgA 是通常存在于体内的抗体 外分泌物。 IgA，人类 IgA 和 IgA 之间的结构域交换蛋白 IgG 和定点突变体将根据其特性进行表征 口服给药时的稳定性、半衰期和生物分布 或静脉注射。他们将根据自己的能力进行表征 结合上皮受体并被上皮受体转运。他们也将是 评估其激活补体级联和结合的能力 特异性针对吞噬细胞上的 IgG 或 IgA 的 Fc 受体。我们也会 尝试开发一种表达带有分泌性抗体的细胞 组件（SC）。 一个目标是生产提供治疗的重组抗体 或预防肠道感染（这是一个重大的健康问题） 全世界。我们将检测最有前途的重组抗体 使用产肠毒素大肠杆菌 (ETEC) 的乳鼠模型 F41 抗原特异性抗体。 F4l 抗体已被证实 给幼犬口服给药的功效和重组抗体或 静脉注射到水坝将评估其预防的能力 致死率并减少定植。体外依从性测定， 凝集和补体介导的细胞毒性将解决 保护机制。 如果要广泛应用重组抗体，需要一种廉价的 表达系统必须可用，我们将重点关注 转基因鸡作为这种表达系统的开发。这 鸡肉的饲养成本低廉，并且针对大量抗体 到蛋黄。产蛋静脉注射碘化抗体 母鸡将被用来确定哪些抗体将被运送到 蛋黄。使用鸡淋巴细胞系测试载体的 Ig 表达 将被转染到 X 期胚盘细胞中，并且这些转染 用于制造嵌合胚胎的细胞。所得鸡将进行测试 检测其血清和产蛋中是否存在嵌合 lg 母鸡。