RECOMBINANT ANTIBODIES FOR INFANT PROTECTION

在目前的拨款中，我们建议扩大我们对遗传学的研究 改造的抗体分子，将我们的注意力集中在 为胎儿和新生儿提供更有效的免疫力。在一个系列中 我们将在实验中识别并生产出最佳抗体 功能特性的组合，为粘膜提供保护 从母亲口服药或经母体转运后表面 胎盘或乳腺。人类免疫球蛋白A是一种抗体，通常在 外分泌分泌物。人免疫球蛋白A和人免疫球蛋白之间的结构域交换蛋白 Ig G和定点突变体将根据它们的 口服给药的稳定性、半衰期和生物分布 或者静脉注射。他们的特点是他们的能力 结合上皮受体并被其转运。他们也将是 评估他们激活补体级联和结合的能力 吞噬细胞上特异性的Ig G或Ig A的Fc受体。我们还将 尝试开发一种表达带有附加分泌物的抗体的细胞 组件(SC)。 其中一个目标是生产出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 世界范围内。我们将检测最有希望的重组抗体 产肠毒素大肠杆菌(ETEC)哺乳小鼠模型的建立 针对F41抗原的抗体。针对F4L的抗体已经证明 仔鼠口服重组抗体和免疫效果观察 将对大坝进行静脉注射，以评估其预防 杀伤力和减少殖民性。在体外黏附试验中， 凝集和补体介导的细胞毒性将解决 保护机制(S)。 如果要广泛应用重组抗体，一种廉价的 表达系统必须可用，我们将把注意力集中在 转基因鸡作为这样一种表达系统的发展。这个 鸡肉的维护成本不高，并以大量抗体为靶标 到蛋黄。蛋鸡静脉注射碘化抗体的研究 母鸡将被用来确定哪些抗体将被输送到 蛋黄。利用鸡淋巴样细胞系检测免疫球蛋白表达载体 将被转染到X期胚层细胞中，并将这些 用于制造嵌合体胚胎的细胞。由此产生的鸡将被测试 在它们的血清和产蛋蛋中存在嵌合LG 母鸡。

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.