Convection-enhanced delivery and systemic mannitol increase gene product distribution of AAV vectors 5, 8, and 9 and increase gene product in the adult mouse brain.
The use of recombinant adeno-associated viral (rAAV) vectors as a means of gene delivery to the central nervous system has emerged as a potentially viable method for the treatment of several types of degenerative brain diseases. However, a limitation of typical intracranial injections into the adult brain parenchyma is the relatively restricted distribution of the delivered gene to large brain regions such as the cortex, presumably due to confined dispersion of the injected particles. Optimizing the administration techniques to maximize gene distribution and gene expression is an important step in developing gene therapy studies. Here, we have found additive increases in distribution when 3 methods to increase brain distribution of rAAV were combined. The convection enhanced delivery (CED) method with the step-design cannula was used to deliver rAAV vector serotypes 5, 8 and 9 encoding GFP into the hippocampus of the mouse brain. While the CED method improved distribution of all 3 serotypes, the combination of rAAV9 and CED was particularly effective. Systemic mannitol administration, which reduces intracranial pressure, also further expanded distribution of GFP expression, in particular, increased expression on the contralateral hippocampi. These data suggest that combining advanced injection techniques with newer rAAV serotypes greatly improves viral vector distribution, which could have significant benefits for implementation of gene therapy strategies.
Byrd Alzheimer's Institute and Department of Molecular Pharmacology and Physiology, University of South Florida College of Medicine, Tampa, FL 33613, USA.
Nikisha
N
Carty
Daniel
D
Lee
Chad
C
Dickey
Carolina
C
Ceballos-Diaz
Karen
K
Jansen-West
Todd E
TE
Golde
Marcia N
MN
Gordon
Dave
D
Morgan
Kevin
K
Nash
D000818:Animals; D001921:Brain; D018481:Convection; D000229:Dependovirus / Q000235:genetics*; D004232:Diuretics / Q000008:administration & dosage / Q000494:pharmacology*; D005822:Genetic Vectors / Q000008:administration & dosage*; D049452:Green Fluorescent Proteins; D006624:Hippocampus / Q000502:physiology; D008353:Mannitol / Q000008:administration & dosage / Q000494:pharmacology*; D051379:Mice; D008810:Mice, Inbred C57BL; D012703:Serotyping; D013238:Stereotaxic Techniques
D004232:Diuretics; D049452:Green Fluorescent Proteins; D008353:Mannitol