Gong Nianqiao, Pleyer Uwe, Vogt Katrin, Anegon Ignacio, Flügel Alexander, Volk Hans-Dieter, Ritter Thomas
Department of Ophthalmology, Charité-University Medicine, Berlin, Germany.
Invest Ophthalmol Vis Sci. 2007 Mar;48(3):1043-52. doi: 10.1167/iovs.06-1084.
To investigate the effect and mechanisms of nerve growth factor (NGF) gene therapy to promote allograft survival in experimental rat corneal transplantation.
A rat major histocompatibility complex (MHC) class I/II disparate corneal transplant model was used. Recipients were randomly assigned to receive either local Ad (Ad)-mediated gene transfer of NGF or a single intraperitoneal injection of AdNGF 1 day before transplantation. Moreover, immunosuppressive therapy was introduced by systemic coapplication of an Ad expressing CTLA4Ig. The efficacy of this treatment was examined by intracorneal mRNA expression analysis of cytokines and cytoprotective molecules by quantitative RT-PCR at day 12 after transplant. Further graft integrity and immune response against adenoviral vectors were investigated.
Local AdNGF-gene transfer significantly prolonged the mean survival time (MST) of rat corneal grafts (16.8 +/- 1.4 days) compared with control grafts (MST, 13.1 +/- 0.3 days; P < 0.03). In contrast, systemic AdNGF gene transfer did not result in improved corneal graft survival (MST, 15.2 +/- 1.0 days). RT-PCR analysis of cornea explants revealed diminished expression of proinflammatory cytokines (IFN-gamma, TNF-alpha) and increased expression of antiapoptotic molecules. In addition, graft endothelial integrity was improved, as measured by the detection of apoptotic cells. Moreover, coapplication of CTLA4Ig further significantly improved graft survival and protective effects of local NGF gene therapy.
This is the first report showing the successful application of a neurotrophin gene therapy to prolong corneal graft survival in an experimental rat transplantation model. Moreover, immunomodulatory therapy further improves graft survival and demonstrates that both anti-inflammatory and cytoprotective mechanisms are involved in the prevention of corneal allograft rejection.
研究神经生长因子（NGF）基因治疗对实验性大鼠角膜移植中同种异体移植物存活的影响及机制。
采用大鼠主要组织相容性复合体（MHC）I/II类不相合角膜移植模型。受体在移植前1天随机接受局部腺病毒（Ad）介导的NGF基因转移或单次腹腔注射AdNGF。此外，通过全身联合应用表达CTLA4Ig的腺病毒引入免疫抑制治疗。在移植后第12天，通过定量逆转录聚合酶链反应（RT-PCR）对角膜内细胞因子和细胞保护分子的mRNA表达进行分析，以检测该治疗的效果。进一步研究移植物的完整性以及对腺病毒载体的免疫反应。
与对照移植物（平均存活时间[MST]，13.1±0.3天）相比，局部AdNGF基因转移显著延长了大鼠角膜移植物的平均存活时间（16.8±1.4天；P<0.03）。相比之下，全身AdNGF基因转移并未改善角膜移植物的存活（MST，15.2±1.0天）。角膜外植体的RT-PCR分析显示促炎细胞因子（IFN-γ、TNF-α）的表达减少，抗凋亡分子的表达增加。此外，通过检测凋亡细胞发现移植物内皮完整性得到改善。此外，联合应用CTLA4Ig进一步显著提高了移植物的存活以及局部NGF基因治疗的保护作用。
这是首份显示神经营养因子基因治疗成功应用于延长实验性大鼠移植模型中角膜移植物存活时间的报告。此外，免疫调节治疗进一步提高了移植物的存活，并证明抗炎和细胞保护机制均参与了角膜同种异体移植排斥反应的预防。
