Project Title: Engineering AAV Vectors for Retinal Gene Delivery (in collaboration with the Schaffer Lab)

Project Description:

Gene therapy is particulary well suited for the treatment of retinal disorders. The gene being a pro-drug, after its delivery, it can provide long term production of a therapeutic protein or RNA product, a very favorable feature for the treatment of highly progressive chronic disorders such as glaucoma (leading cause of irreversible blindness worlwide), AMD (leading cause of blindness among older Americans), and photoreceptor diseases. Moreover, the eye is a readily accessible region for surgical injection.

Even though retinal disorders are highly complex with many likely underlying genetic causes, all pathological events of retinal diseases are due to death of neurons. Therefore a gene therapy focused on the delivery of general neuroprotective factors is highly promising since it does not rely on precise molecular knowledge of the mechanism causing cell death.

Müller glial cells are very numerous, spaning the entire thickness of the retina and are in close contact with neuronal cells making them ideal candidates for the secretion of neuroprotective factors. Since Müller cells span the entire retina, they are accessible form the vitreous side. Therefore transducing this single cell type thru intravitreal injection has the potential to protect the entire retina. Intravitrael injection is signigicantly less invasive and traumatic then subretinal injection and trauma should be avoided in diseased retina.

Recently, it has been shown that provided with the right choice of viral pseudotype, regulatory promotor and surgical delivery site, high levels of Müller cell transduction can be achieved using lentiviral vectors. Unfortunately with lentivirus the subretinal approach consistently yielded gene expression whereas the intravitreal approach yielded none. The reason why Lentivirus cannot access Müller cells from the intravitrael side could be the relative instability and large particle size (80-100nm) of this virus. Another virus, AAV, has none of these inconveniences and has all the advantages of lentiviral gene delivery such as long term gene expression and low immunogenicity. The aim of my project is to find AAV varients than can specifically transduce Müller cells from the intravitreus side, providing a very clinically relevant system for gene therapy of renial disorders.

Deniz Dalkara- Mourot

MSc And Ph.D.

Universite de Louis Pasteur

Strasbourg, France

Post Doc: Max Planck Institute of Biophysics

Frankfurt, Germany