Bicistronic Lentiviruses Containing a Viral 2A Cleavage Sequence Reliably Co-Express Two Proteins and Restore Vision to an Animal Model of LCA1

The disease processes underlying inherited retinal disease are complex and are not completely understood. Many of the corrective gene therapies designed to treat diseases linked to mutations in genes specifically expressed in photoreceptor cells restore function to these cells but fail to stop progression of the disease. There is growing consensus that effective treatments for these diseases will require delivery of multiple therapeutic proteins that will be selected to treat specific aspects of the disease process. The purpose of this study was to design a lentiviral transgene that reliably expresses all of the proteins it encodes and does so in a consistent manner among infected cells. We show, using both in vitro and in vivo analyses, that bicistronic lentiviral transgenes encoding two fluorescent proteins fused to a viral 2A-like cleavage peptide meet these expression criteria. To determine if this transgene design is suitable for therapeutic applications, we replaced one of the fluorescent protein genes with the gene encoding guanylate cyclase -1 (GC1) and delivered lentivirus carrying this transgene to the retinas of the GUCY1*B avian model of Leber congenital amaurosis – 1 (LCA1). GUCY1*B chickens carry a null mutation in the GC1 gene that disrupts photoreceptor function and causes blindness at hatching, a phenotype that closely matches that observed in humans with LCA1. We found that treatment of these animals with the 2A lentivector encoding GC1 restored vision to these animals as evidenced by the presence of optokinetic reflexes. We conclude that 2A-like peptides, with proper optimization, can be successfully incorporated into therapeutic vectors designed to deliver multiple proteins to neural retinal. These results highlight the potential of this vector design to serve as a platform for the development of combination therapies designed to enhance or prolong the benefits of corrective gene therapies

Reducing the costs of chronic kidney disease while delivering quality health care : a call to action

The treatment of chronic kidney disease (CKD) and of end-stage renal disease (ESRD) imposes substantial societal costs. Expenditure is highest for renal replacement therapy (RRT), especially in-hospital haemodialysis. Redirection towards less expensive forms of RRT (peritoneal dialysis, home haemodialysis) or kidney transplantation should decrease financial pressure. However, costs for CKD are not limited to RRT, but also include nonrenal health-care costs, costs not related to health care, and costs for patients with CKD who are not yet receiving RRT. Even if patients with CKD or ESRD could be given the least expensive therapies, costs would decrease only marginally. We therefore propose a consistent and sustainable approach focusing on prevention. Before a preventive strategy is favoured, however, authorities should carefully analyse the cost to benefit ratio of each strategy. Primary prevention of CKD is more important than secondary prevention, as many other related chronic diseases, such as diabetes mellitus, hypertension, cardiovascular disease, liver disease, cancer, and pulmonary disorders could also be prevented. Primary prevention largely consists of lifestyle changes that will reduce global societal costs and, more importantly, result in a healthy, active, and long-lived population. Nephrologists need to collaborate closely with other sectors and governments, to reach these aims