Strategy for Treating Motor Neuron Diseases Using a Fusion Protein of Botulinum Toxin Binding Domain and Streptavidin for Viral Vector Access: Work in Progress

Toxins

Daniel B. Drachman¹  Robert N. Adams¹  Uma Balasubramanian¹ 

[1] Department of Neurology, Johns Hopkins School of Medicine, 600 North Wolfe Ave, Baltimore, MD 21287, USA;

关键词: botulinum toxin;    binding domain;    motor neuron diseases;    ALS;    SMA;    motor neurons;    therapeutic targeting;    gene transfer;    viral vectors;   

DOI  :  10.3390/toxins2122872

来源: mdpi

【 摘 要 】

Although advances in understanding of the pathogenesis of amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA) have suggested attractive treatment strategies, delivery of agents to motor neurons embedded within the spinal cord is problematic. We have designed a strategy based on the specificity of botulinum toxin, to direct entry of viral vectors carrying candidate therapeutic genes into motor neurons. We have engineered and expressed fusion proteins consisting of the binding domain of botulinum toxin type A fused to streptavidin (SAv). This fusion protein will direct biotinylated viral vectors carrying therapeutic genes into motor nerve terminals where they can enter the acidified endosomal compartments, be released and undergo retrograde transport, to deliver the genes to motor neurons. Both ends of the fusion proteins are shown to be functionally intact. The binding domain end binds to mammalian nerve terminals at neuromuscular junctions, ganglioside GT1b (a target of botulinum toxin), and a variety of neuronal cells including primary chick embryo motor neurons, N2A neuroblastoma cells, NG108-15 cells, but not to NG CR72 cells, which lack complex gangliosides. The streptavidin end binds to biotin, and to a biotinylated Alexa 488 fluorescent tag. Further studies are in progress to evaluate the delivery of genes to motor neurons in vivo, by the use of biotinylated viral vectors.

【 授权许可】

CC BY   
© 2010 by the authors; licensee MDPI, Basel, Switzerland