Résumé :
|
Central nervous system transduction has been extensively studied with a wide variety of viral vectors. However, peripheral nervous system transduction has not brought that much attention to researchers so far, despite the importance of acquired and inherited neuropathies, neuromuscular diseases or pain treatment, among other pathologies. Thus, we have characterized the tropism and transduction efficiency of different AAV pseudotypes in primary and established Schwann cell lines as well as in vivo, through sciatic nerve injection in the mouse. Among the AAV pseudotypes tested, AAV2/8 transduced Schwann cells more efficiently, both in vitro and in vivo. On the other hand, AAV2/2 infected preferentially sensory neurons and AAV2/1 transduced both Schwann cells and neurons. Expression of marker genes coded by the different vectors was still present 10 weeks after administration, the overall duration of the experiment. We also analyzed the generation of neutralizing antibodies against AAVs in the infected mice. Antibody titers were higher against AAV1 than against AAV2 or AAV8. Indeed, animals injected with AAV8 showed the lower titers of neutralizing antibodies against this serotype, correlating with higher expression overtime. These results suggest that AAV8 may be a suitable tool for gene therapy treatment of diseases affecting Schwann cells. To improve transduction of peripheral neurons, we infected organotypic cultures of murine dorsal root ganglia with different serotypes of AAVs and human and canine adenoviruses. These vectors were also tested in vivo by intrathecal administration to the lumbar region of mice. We observed high levels of expression in sensory neurons with AAV2/1 and with human Ad5. We are currently evaluating efficiency of canine adenovirus and human Ad40 serotype in targeting sensory and motoneurons. In the near future, helper-dependent adenovirus will be assayed with therapeutic genes in a mouse model of disease. Financed by AFM (#12277; AFM2007/12763AE), ISCIII (PI051705) and Generalitat de Catalunya (2006FI00762; 2004FI00970).
|