TREATMENT OF RETINAL DEGENERATIVE DISIESE BY TRANSPLANTATION OF GENE TRANSFERRED CELLS

本研究的目的是通过转移抑制感光细胞变性的有效基因，将细胞移植到视网膜下腔，治疗视网膜变性疾病。为了达到这个目的，我们计划使用虹膜色素上皮（IPE）细胞作为移植细胞的候选者。使用IPE细胞的优点是可以进行自体细胞移植。IPE细胞易于从眼内获得并在培养条件下维持。将该基因转染到体外培养的IPE细胞中，对光感受器的变性有保护作用，使得只转染靶细胞成为可能，经过3年的研究，我们明确了以下五点：1. IPE细胞具有与视网膜色素上皮细胞相似的特性。2.将IPE细胞移植到视网膜下间隙，IPE细胞在移植区域存活6个月。3.移植的IPE细胞具有与RPE细胞相似的吞噬活性，表明移植的IPE细胞在视网膜下腔发挥功能。4.未发现IPE移植引起的不良反应. 5.有报道称，腺病毒载体用于基因转移时可引起全身感染，引起炎症反应。我们的研究表明，体外基因转移可能使全身感染率降低，即使使用腺病毒载体进行基因转染。然而，我们发现，腺相关病毒载体是有用的基因转移的表达周期和不良反应。BDNF转染的IPE细胞移植对光或谷氨酸毒性诱导的视网膜变性有保护作用。

Our purpose of this research is to treat retinal degenerative diseise by transplanting cells in the sub retinal space which are modified by transferring effective gene for inhibition of photoreceptor degeneration. To achieve this purpose, we were planning to use the iris pigment epithelial (IPE) cells as a candidate for the transplanting cells. The advantage of using IPE cells is to be possible to do the autolougous cell transplantation. IPE cells could be obtained from the eye easily and maintain under the culture. To transfer the gene to IPE cells in vitro which has the protective effect on the photoreceptor degeneration makes possible to transfer the target cells only.We have clarified below five things for 3 years.1. IPE cell has similar properties with the retinal pigernent epithelial cells. 2. When IPE cells were transplanted into sub retinal space, IPE cells have been survived in the transplanted area for 6 months. 3. The transplanted IPE cells had the phagocytic activity like RPE cells, which indicated transplanted IPE cells functionally worked in sub-retinal space. 4. We could not any adverse effect caused by the IPE transplantation. 5. It has been reported adenovirus caused systemic infection which induced inflammatory response when adenovirus vector was used for the gene transfer. Our study showed possibilities that in vitro transfer of gene made systemic infection rate decrease even if the adenovirus vector was used for the gene transfection. However we found that adeno-associated virus vector were useful for the gene transfer in view of expression periods and adverse effect. The transplantation of BDNF transferred IPE cells has protective effects on retinal degeneration induced by light or glutamate toxicity.