NOVEL METHOD FOR MUCOSAL GENE DELIVERY

通过受体介导的内吞作用将基因递送到靶细胞是一种新的生物学方法。 一个非常吸引人的基因治疗策略。 许多目标 基因治疗是上皮细胞， 机关 例如，气道细胞是表达 囊性纤维化跨膜传导调节因子（CFTR）， 是囊性纤维化的病变。 上皮细胞的顶端 面向内腔的表面和面向下面的基底外侧表面 细胞理想情况下，人们希望通过顶端或 上皮细胞的腔表面。 例如，在肺中， 可以通过将基因导入气道， 滴注或甚至雾化。 然而， 大多数上皮细胞对基因递送呈现出难以克服的障碍。 大多数递送方法，如脂质体或病毒载体， 当应用于极化良好的上皮细胞的顶面时， 培养的或尤其是体内的细胞。这些受体通常 用于受体介导的基因传递的所有基因都位于 基底外侧面 顶端表面含有很少的受体， 高效内吞。一种用于基底外侧的受体 基因递送是多聚免疫球蛋白受体（pIgR）， 在表达CFTR的气道细胞上特别丰富。一般来说， pIgR的细胞外结构域在顶端表面被切掉， 这使得该受体难以用于顶端基因摄取。 我们 已经发现了一种新的方法，利用pIgR有效的顶端基因 摄取。 在这个试点赠款提案中，我们将在培养的 气道上皮细胞和整个大鼠的肺中。

Delivery of genes to target cells by receptor-mediated endocytosis is a very appealing strategy for gene therapy. Many of the targets for gene therapy are epithelial cells that line a variety of important organs. For instance, airway cells are the main site of expression of the cystic fibrosis transmembrane conductance regulator (CFTR), which is the lesion in cystic fibrosis. Epithelial cells have an apical surface facing the lumen, and a basolateral surface facing underlying cells. Ideally, one would like to deliver genes through the apical or luminal surface of epithelial cells. In the lung, for instance, one could deliver the genes by introduction into the airways, via instillation or even aerosolization. However, the apical surface of most epithelial cells presents a formidable barrier to gene delivery. Most delivery methods, such as liposomes or viral vectors, work very poorly when applied to the apical surface of well polarized epithelial cells in culture or especially in vivo. The receptors that are usually used for receptor-mediated gene delivery are all located at the basolateral surface. The apical surface contains few receptors that are efficiently endocytosed. One receptor that has been used for basolateral gene delivery is the polymeric immunoglobulin receptor (pIgR), which is particularly abundant on the airway cells that express CFTR. Ordinarily, the extracellular domain of pIgR is cleaved off at the apical surface, which makes this receptor difficult to use for apical gene uptake. We have found a novel method to use the pIgR for effective apical gene uptake. In this pilot grant proposal we will test this in cultured airway epithelial cells and in the lungs of whole rats.