Ribera Albert, Haurigot Virginia, Garcia Miguel, Marcó Sara, Motas Sandra, Villacampa Pilar, Maggioni Luca, León Xavier, Molas Maria, Sánchez Víctor, Muñoz Sergio, Leborgne Christian, Moll Xavier, Pumarola Martí, Mingozzi Federico, Ruberte Jesús, Añor Sònia, Bosch Fatima
Center of Animal Biotechnology and Gene Therapy, Department of Biochemistry and Molecular Biology.
Généthon, 91000 Evry, France and.
Hum Mol Genet. 2015 Apr 1;24(7):2078-95. doi: 10.1093/hmg/ddu727. Epub 2014 Dec 18.
Gene therapy is an attractive tool for the treatment of monogenic disorders, in particular for lysosomal storage diseases (LSD) caused by deficiencies in secretable lysosomal enzymes in which neither full restoration of normal enzymatic activity nor transduction of all affected cells are necessary. However, some LSD such as Mucopolysaccharidosis Type IIIB (MPSIIIB) are challenging because the disease's main target organ is the brain and enzymes do not efficiently cross the blood-brain barrier even if present at very high concentration in circulation. To overcome these limitations, we delivered AAV9 vectors encoding for α-N-acetylglucosaminidase (NAGLU) to the Cerebrospinal Fluid (CSF) of MPSIIIB mice with the disease already detectable at biochemical, histological and functional level. Restoration of enzymatic activity in Central Nervous System (CNS) resulted in normalization of glycosaminoglycan content and lysosomal physiology, resolved neuroinflammation and restored the pattern of gene expression in brain similar to that of healthy animals. Additionally, transduction of the liver due to passage of vectors to the circulation led to whole-body disease correction. Treated animals also showed reversal of behavioural deficits and extended lifespan. Importantly, when the levels of enzymatic activity were monitored in the CSF of dogs following administration of canine NAGLU-coding vectors to animals that were either naïve or had pre-existing immunity against AAV9, similar levels of activity were achieved, suggesting that CNS efficacy would not be compromised in patients seropositive for AAV9. Our studies provide a strong rationale for the clinical development of this novel therapeutic approach as the treatment for MPSIIIB.
基因治疗是治疗单基因疾病的一种有吸引力的工具，特别是对于由可分泌的溶酶体酶缺乏引起的溶酶体贮积病（LSD），在这类疾病中，既不需要完全恢复正常酶活性，也不需要转导所有受影响的细胞。然而，一些LSD，如IIIB型粘多糖贮积症（MPSIIIB）具有挑战性，因为该疾病的主要靶器官是大脑，即使酶在循环中以非常高的浓度存在，也不能有效地穿过血脑屏障。为了克服这些限制，我们将编码α-N-乙酰氨基葡萄糖苷酶（NAGLU）的AAV9载体递送至MPSIIIB小鼠的脑脊液（CSF）中，此时该疾病在生化、组织学和功能水平上已可检测到。中枢神经系统（CNS）中酶活性的恢复导致糖胺聚糖含量和溶酶体生理学正常化，解决了神经炎症，并恢复了大脑中与健康动物相似的基因表达模式。此外，由于载体进入循环导致肝脏转导，从而实现了全身疾病的纠正。治疗后的动物还表现出行为缺陷的逆转和寿命的延长。重要的是，当在向未接触过或已对AAV9具有预先免疫的动物施用犬NAGLU编码载体后，在犬的脑脊液中监测酶活性水平时，获得了相似的活性水平，这表明AAV9血清阳性的患者中枢神经系统的疗效不会受到影响。我们的研究为这种新型治疗方法作为MPSIIIB的治疗方法的临床开发提供了有力的理论依据。
