Journal Article

AAV2-mediated CLN2 gene transfer to rodent and non-human primate brain results in long-term TPP-I expression compatible with therapy for LINCL

Sanders, C T, De, B, Rostkowski, A B, Redmond, D E, Sladek, J R, Peterson, D A, Blanchard, B, Sondhi, D, Kaminsky, S M, Crystal, R G, Bjugstad, K, Giannaris, E L, Mendez, B S, Hackett, N R, Leopold, P L

2005

Overview

Late infantile neuronal ceroid lipofuscinosis (LINCL) is a fatal, autosomal recessive disease resulting from mutations in the CLN2 gene with consequent deficiency in its product tripeptidyl peptidase I (TPP-I). In the central nervous system (CNS), the deficiency of TPP-I results in the accumulation of proteins in lysosomes leading to a loss of neurons causing progressive neurological decline, and death by ages 10–12 years. To establish the feasibility of treating the CNS manifestations of LINCL by gene transfer, an adeno-associated virus 2 (AAV2) vector encoding the human CLN2 cDNA (AAV2 CU hCLN2) was assessed for its ability to establish therapeutic levels of TPP-I in the brain. In vitro studies demonstrated that AAV2 CU hCLN2 expressed CLN2 and produced biologically active TPP-I protein of which a fraction was secreted as the pro-TPP-I precursor and was taken up by nontransduced cells (ie, cross-correction). Following AAV2-mediated CLN2 delivery to the rat striatum, enzymatically active TPP-I protein was detected. By immunohistochemistry TPP-I protein was detected in striatal neurons (encompassing nearly half of the target structure) for up to 18 months. At the longer time points following striatal administration, TPP-I-positive cell bodies were also observed in the substantia nigra, frontal cerebral cortex and thalamus of the injected hemisphere, and the frontal cerebral cortex of the noninjected hemisphere. These areas of the brain contain neurons that extend axons into the striatum, suggesting that CNS circuitry may aid the distribution of the gene product. To assess the feasibility of human CNS delivery, a total of 3.6 × 10 11 particle units of AAV2 CU hCLN2 was administered to the CNS of African green monkeys in 12 distributed doses. Assessment at 5 and 13 weeks demonstrated widespread detection of TPP-I in neurons, but not glial cells, at all regions of injection. The distribution of TPP-I-positive cells was similar between the two time points at all injection sites. Together, these data support the development of direct CNS gene transfer using an AAV2 vector expressing the CLN2 cDNA for the CNS manifestations of LINCL.

• Publisher: Nature Publishing Group UK,Nature Publishing Group
• Subject: Adeno-associated virus 2 / Aminopeptidases / Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy / Animals / Applied cell therapy and gene therapy / Biological activity / Biological and medical sciences / Biomedical and Life Sciences / Biomedicine / Biotechnology / Brain - metabolism / Brain - virology / Cell Biology / Central nervous system / Cercopithecus aethiops / Cerebral cortex / CLN2 protein / Cortex (frontal) / Dependovirus - genetics / Dipeptidyl-Peptidases and Tripeptidyl-Peptidases / Endopeptidases - analysis / Endopeptidases - genetics / Endopeptidases - metabolism / Fundamental and applied biological sciences. Psychology / Gene Expression / Gene Therapy / Gene transfer / Genes, Recessive / Genetic Therapy - methods / Genetic Vectors - administration & dosage / Glial cells / Health. Pharmaceutical industry / Human Genetics / Humans / Immunoenzyme Techniques / Immunohistochemistry / Industrial applications and implications. Economical aspects / Injection / Lysosomes / Male / Medical sciences / Microinjections / Models, Animal / Nanotechnology / Neostriatum / Neuronal ceroid lipofuscinosis / Neuronal Ceroid-Lipofuscinoses - metabolism / Neuronal Ceroid-Lipofuscinoses - therapy / Neuronal-glial interactions / Neurons / Peptidase / Primates / Proteins / Rats / Rats, Inbred F344 / research-article / Serine Proteases / Substantia nigra / Thalamus / Time Factors / Transfusions. Complications. Transfusion reactions. Cell and gene therapy