TRANSCELLULAR TRANSPORT OF IMMUNOGLOBULINS

建议进行进一步的研究，以确定细胞机制 母体免疫球蛋白G(Ig G)选择性地跨 受体介导的新生大鼠和小鼠肠上皮 内吞作用。提出了单个项目来评估其后果 正常和异常的运输功能。(1)移动 将分析膜成分和囊泡内容物的分类 在体肠细胞选择性地吞噬免疫球蛋白 超微结构示踪剂包括免疫球蛋白示踪剂结合物，阳离子铁蛋白， 标记的凝集素和抗刷状边缘抗体结合物。可能的 溶酶体和其他代谢抑制剂的效果将被调查。 (2)标记的免疫球蛋白与其膜受体的pH依赖性结合将 用隔离刷子同时使用超微结构和125-I分析进行研究 边界和完好无损的细胞。分析条件和不同因素的影响 对结合常数和结合位点数的处理将是 已评估。(3)可能影响受体运动的因素。 顶端细胞表面和内吞泡泡的形成 用分离的刷状缘细胞和体外培养的肠道细胞进行研究。 (4)乳鼠进入乳鼠体内的超微结构机制 乳腺肿瘤病毒，一种已知的跨 将对哺乳期间的肠道进行研究。可能扮演的角色 将对运输和感染过程中的特异性抗体进行评估。

Further studies are proposed to detial the cellular mechanisms whereby maternal immunoglobulin G (IgG) is selectively transferred across the intestinal epithelium of neonatal rats and mice by receptor-mediated endocytosis. Individual projects are proposed to evaluate the consequences of both normal and abnormal transport function. (1) The movement of membrane components and sorting of vesicle contents will be analyzed during selective IgG endocytosis by intestinal cells in situ using a variety of ultrastructural tracers including IgG-tracer conjugates, cationic ferritin, labeled lectins and anti-brush border antibody conjugates. Possible effects of lysosomal and other metabolic inhibitors will be investigated. (2) The pH-dependent binding of labled IgG to its membrane receptors will be studied using both ultrastructural and 125-I assays with isolated brush borders and intact cells. Effects of assay conditions and various treatments on the association constant and number of binding sites will be evaluated. (3) Factors that might influence the movement of receptors on the apical cell surface and the formation of endocytic vesicles will be investigated using isolated brush borders and intestinal cell in vitro. (4) The ultrastructural mechanism of entry into the neonatal mouse of mammary tumor virus, a pathogen known to be transferred across the intestine during the suckling period, will be studied. The possible role of specific antibody in transport and infection will be evaluated.