新型基因療法可用於治療肌營養不良症
作者:
小柯機器人發布時間:2019/10/9 11:03:38
美國賓夕法尼亞州立大學Hansell H. Stedman研究團隊發現,無免疫原性的抗肌萎縮蛋白相關蛋白基因療法,可用於治療動物模型中的肌營養不良症。2019年10月7日,國際知名學術期刊《自然—醫學》在線發表了這一成果。
研究人員設計了一種密碼子優化的合成轉基因,其編碼可通過腺相關病毒(AAV)載體遞送的微型抗肌萎縮蛋白相關蛋白(µUtro)。研究人員發現µUtro是肌營養不良蛋白的一種功能強大的非免疫原性替代品,可防止大小動物模型中肌肉營養不良帶來的最有害的組織學和生理學影響。對新生的肌營養不良蛋白缺乏症的mdx小鼠全身施用AAV-µUtro之後,在整個成年體重增長過程中,完全抑制了壞死和再生的組織學和生化指標。在肌營養不良蛋白缺陷型金毛尋回犬模型中,即使在最強壯的肌肉中,μUtro也無毒地防止了心肌壞死。在嚴格的免疫原性測試中,在基因缺失的德國短毛指示犬模型中,µUtro的局部表達沒有產生細胞介導的免疫反應,這與針對類似構建的µDystrophin(µDystro)所產生的強烈T細胞反應不同。這些發現支持了一種模型,即抗肌萎縮蛋白相關蛋白衍生療法可用於治療臨床肌營養不良蛋白缺乏症,並且在蛋白及其微型化的情況下具有良好的免疫學特徵同時具有功能。
據悉,杜氏肌營養不良症(DMD)基因的關鍵產物是抗肌萎縮蛋白,它是一種棒狀蛋白,可保護橫紋肌細胞免受收縮誘導的損傷。肌營養不良蛋白相關的蛋白質(或卵磷脂)保留了肌營養不良蛋白的大部分結構和蛋白質結合元件。重要的是,DMD患者的正常胸腺表達應通過中樞免疫耐受來保護抗肌萎縮蛋白相關蛋白(也稱為utrophin)。
附:英文原文
Title: Non-immunogenic utrophin gene therapy for the treatment of muscular dystrophy animal models
Author: Yafeng Song, Leon Morales, Alock S. Malik, Andrew F. Mead, Christopher D. Greer, Marilyn A. Mitchell, Mihail T. Petrov, Leonard T. Su, Margaret E. Choi, Shira T. Rosenblum, Xiangping Lu, Daniel J. VanBelzen, Ranjith K. Krishnankutty, Frederick J. Balzer, Emanuele Loro, Robert French, Kathleen J. Propert, Shangzhen Zhou, Benjamin W. Kozyak, Peter P. Nghiem, Tejvir S. Khurana, Joe N. Kornegay, Hansell H. Stedman
Issue&Volume: 2019-10-07
Abstract: The essential product of the Duchenne muscular dystrophy (DMD) gene is dystrophin1, a rod-like protein2 that protects striated myocytes from contraction-induced injury3,4. Dystrophin-related protein (or utrophin) retains most of the structural and protein binding elements of dystrophin5. Importantly, normal thymic expression in DMD patients6 should protect utrophin by central immunologic tolerance. We designed a codon-optimized, synthetic transgene encoding a miniaturized utrophin (Utro), deliverable by adeno-associated virus (AAV) vectors. Here, we show that Utro is a highly functional, non-immunogenic substitute for dystrophin, preventing the most deleterious histological and physiological aspects of muscular dystrophy in small and large animal models. Following systemic administration of an AAV-Utro to neonatal dystrophin-deficient mdx mice, histological and biochemical markers of myonecrosis and regeneration are completely suppressed throughout growth to adult weight. In the dystrophin-deficient golden retriever model, Utro non-toxically prevented myonecrosis, even in the most powerful muscles. In a stringent test of immunogenicity, focal expression of Utro in the deletional-null German shorthaired pointer model produced no evidence of cell-mediated immunity, in contrast to the robust T cell response against similarly constructed Dystrophin (Dystro). These findings support a model in which utrophin-derived therapies might be used to treat clinical dystrophin deficiency, with a favorable immunologic profile and preserved function in the face of extreme miniaturization. A gene therapy vector expressing micro-utrophin provides functional replacement of lost dystrophin, and lacks the adverse immunogenicity associated with direct dystrophin therapy, in rodent and canine models of Duchenne muscular dystrophy.
DOI: 10.1038/s41591-019-0594-0
Source:https://www.nature.com/articles/s41591-019-0594-0