INTERCELLULAR TRANSFER OF GPI ANCHORED PROTEINS

GPI锚定蛋白在细胞质膜上表达 真核细胞。它们在人类中的正常功能范围从 胚胎发生和神经发生的调控以保护 补体介导的细胞破坏。致病过程涉及 这类蛋白质包括对细胞结构的破坏 与致癌、寄生虫感染和 普恩病毒相关疾病。理解GPI锚定的贩运 蛋白质可能导致对这些疾病的进一步了解，以及 开发新的治疗方法。我们调查了贩卖原住民 和哺乳动物细胞中的重组GPI-蛋白。天然GPI-内吞 在造血细胞中检测通路。使用抗体 这些细胞的特异性并随后将这些抗体 用荧光标记的亲和素，我们证明了有效的内吞作用。 这种复合体在K562红白血病细胞中的表达。我们还测试了 假设所有表面蛋白质的聚集，包括那些 由糖基磷脂酰肌醇锚定的也能有效地激活 内吞作用。重组的CD4-GPI在体外有很高水平的表达 人和啮齿动物细胞系以及直接和间接的细胞间 用基于荧光的方法测定蛋白质的转移量。 允许合胞体形成的蛋白质膜异种移植 表达HIV gp160的细胞。适当性和衰减性的生产 目前正在对来自这些细胞的艾滋病毒进行调查。基于这些 实验中，我们计划继续研究GPI蛋白的运输 在哺乳动物细胞中。了解天然GPI-蛋白的生物学特性 表达应提高我们对重组GPI-蛋白的理解 在哺乳动物细胞中表达。临床应用广泛，应用前景广阔。 包括基因治疗和疫苗开发。

GPI-anchored proteins are expressed on the plasma membranes of eukaryotic cells. Their normal functions in humans range from the regulation of embryogenesis and neurogenesis to protection from complement-mediated cell destruction. Pathogenic processes involving this class of proteins include disruption of cellular architecture associated with carcinogenesis, parasitic infections, and prion-associated diseases. Understanding the trafficking of GPI-anchored proteins may lead to a further understanding of these diseases and the development of novel therapies. We explored the trafficking of native and recombinant GPI-proteins in mammalian cells. Native GPI-endocytotic pathways were examined in hematopoietic cells. Using antibodies specific for those cells and subsequent crosslinking those antibodies with fluorescently labeled avidin we demonstrated efficient endocytosis of such complexes in K562 erythroleukemia cells. We also tested the hypothesis that clustering of all surface proteins including those anchored by glycosylphosphatidylinositol can also efficiently activate endocytosis. Recombinant CD4-GPI was expressed at very high levels on human and rodent cell lines, and the direct and indirect intercellular transfer of the protein was measured by fluorescence-based assays. Membrane xenografting of the protein permitted syncytium formation with HIV gp160 expressing cells. The production of competent and attenuated HIV from those cells is currently being investigated. Based on these experiments, we plan to continue the study of GPI-protein trafficking in mammalian cells. Understanding the biology of native GPI-protein expression should enhance our understanding of recombinant GPI-protein expression in mammalian cells. The clinical applications are broad and include gene therapy and vaccine development.