Abud Murilo, Baranov Petr, Hicks Caroline, Patel Sara, Lieppman Burke, Regatieri Caio, Sinden John, Isaac David, Avila Marcos, Young Michael
Schepens Eye Research Institute, Massachusetts Eye and Ear, an affiliate of Harvard Medical School, Boston, MA, USA ; Federal University of Goias, Goiania, Brazil.
Schepens Eye Research Institute, Massachusetts Eye and Ear, an affiliate of Harvard Medical School, Boston, MA, USA.
Transl Vis Sci Technol. 2015 Sep 22;4(5):6. doi: 10.1167/tvst.4.5.6. eCollection 2015 Sep.
The development of photoreceptor replacement therapy for retinal degenerative disorders requires the identification of the optimal cell source and immunosuppressive regimen in a large animal model. Allotransplants are not acutely rejected in swine subretinal space, although it is not known if survival can be improved with immunosuppression. Here we investigated the survival and integration of expanded pig retinal progenitor cells (pRPCs) in normal recipients with and without transient anti-inflammatory suppression.
pRPCs were derived from the neural retina of E60 GFP transgenic pigs, expanded for six passages, characterized, and transplanted into the subretinal space of 12 pigs. Six recipients received a single intravitreal injection of rapamycin and dexamethasone.
pRPCs expressed the photoreceptor development genes Sox2, Pax6, Lhx2, Crx, Nrl, and Recoverin in vitro. Transplanted cells were identified in 9 out of 12 recipients 4 weeks after the injection. pRPCs integrated primarily into the photoreceptor inner segment layer and outer nuclear layer with single cells present in the inner nuclear layer. Donor cells remained recoverin-positive and acquired rhodopsin. We did not observe any signs of graft proliferation. The immunosuppression did not affect the survival or distribution of grafts. No macrophage infiltration or loss of retinal structure was observed in either group.
Local immunosuppression with rapamycin and dexamethasone does not improve the outcome of pRPC allotransplantation into the subretinal space.
Survival and integration of pRPC together with the lack of graft proliferation suggests that allogeneic RPC transplantation without transient immunosuppression is a favorable approach for photoreceptor cell replacement.
视网膜退行性疾病光感受器替代疗法的发展需要在大型动物模型中确定最佳细胞来源和免疫抑制方案。同种异体移植在猪视网膜下间隙不会被急性排斥，尽管尚不清楚免疫抑制是否能提高其存活率。在此，我们研究了经扩增的猪视网膜祖细胞（pRPC）在接受或未接受短暂抗炎抑制的正常受体中的存活和整合情况。
pRPC来源于E60绿色荧光蛋白转基因猪的神经视网膜，扩增6代，进行特征鉴定，然后移植到12头猪的视网膜下间隙。6只受体接受了一次玻璃体内注射雷帕霉素和地塞米松。
pRPC在体外表达光感受器发育相关基因Sox2、Pax6、Lhx2、Crx、Nrl和恢复蛋白。注射后4周，在12只受体中的9只中发现了移植细胞。pRPC主要整合到光感受器内节层和外核层，在内核层有单个细胞存在。供体细胞保持恢复蛋白阳性并获得视紫红质。我们未观察到移植物增殖的任何迹象。免疫抑制不影响移植物的存活或分布。两组均未观察到巨噬细胞浸润或视网膜结构丧失。
雷帕霉素和地塞米松的局部免疫抑制不能改善pRPC同种异体移植到视网膜下间隙的效果。
pRPC的存活和整合以及缺乏移植物增殖表明，无需短暂免疫抑制的异体RPC移植是光感受器细胞替代的一种有利方法。
