451. 430. Immune System Regulation of Transgene Expression from High-Capacity Gutless Adenoviral Vectors in the Mouse Brain: Very Long Term Expression Following Pre-Immunization
- Author
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Maria G. Castro, Jeffrey M. Zirger, Pedro R. Lowenstein, Philip Ng, Donna Palmer, Weidong Xiong, and Carlos Barcia
- Subjects
Pharmacology ,Pars compacta ,viruses ,animal diseases ,Transgene ,Genetic enhancement ,Stereology ,Substantia nigra ,Striatum ,Biology ,Virology ,Andrology ,Globus pallidus ,nervous system ,Drug Discovery ,Gene expression ,Genetics ,Molecular Medicine ,Molecular Biology - Abstract
Top of pageAbstract Gene expression from first generation adenovirus vectors in the CNS is efficient and safe in na|[iuml]|ve animals. However, transgene expression is eliminated within 30 days in animals immunized against adenovirus. High-capacity adenovirus (HC-Adv) provide an advantage in that they sustain transgene expression in the brain even in animals that have been preimmunized against adenovirus, preceding the administration of HC-Adv. In the present experiment we analyzed the long term expression of a HC-Adv in the brain of mice preimmunized with a first generation adenovirus. C57Bl/6 mice were immunized ip with 1|[times]|108 i.u. of RAdHPRT, and 30 days later they were injected in the striatum with 1|[times]|106 bfu of HC-Adv-STkmCMV-LacZ. Mice were perfused-fixed at different time points after the intrastriatal injection (14, 30, 60 90 and 180 days). Brains were then removed and cut in 40mm thick serial sections. Immunohistochemistry for |[beta]|-galactosidade was performed and expressing cells and fibers were counted by quantitative unbiased stereology. After 14 days the expression in the striatum was high covering the entire caudate-putamen complex. Fibers and neurons were observed in the motor cortex, globus pallidus, entopeduncular nucleus, amygdaloid complex and Substantia nigra pars compacta. 30 days after the injection, the expression of the transgene in the striatum was diminished 30% in non immunized animals, while in immunized animals it was reduced by more than 50%. However after 60 days the expression was stable in both groups, and this expression lasted for up to 6 months. These results confirm the stable expression of the transgene in the brain with HC-Adv even in animals immunized systemically before the delivery of HC-Adv into the brain, and demonstrate the usefulness of HC-Adv as powerful tool for gene therapy for the treatment of neurological disorders such as Parkinson's and Huntington's disease.
- Published
- 2005