EN
We compared the efficiency and specificity of in vivo transduction of spinal cord cells in adult, spinalized rats, with adeno-associated viral vectors: AAV1/2 and AAV5, with human synapsin (hSYN) and murine cytomegalovirus (mCMV) promoters, respectively. Both AAV vectors carried eGFP transgen, and were injected bilaterally to the lumbar L1 segment immediately after spinal transection at the Th10/11. At 5-6 weeks postlesion (1) the distribution and extent of eGFP expressing cells and fibers and (2) their phenotype (immunohistochemical identification; IHC) were determined. To evaluate virus expansion we compared distribution of eGFP signal at the microscopical reconstructions (parasagittal sections). A comparison between serotypes showed, that caudorostral range of cells expressing eGFP was comparable (AAV1/2 – 6.8 mm; AAV5 – 8 mm), with a core of transduced cells (AAV1/2 – 4.2/4.6 mm; AAV5 – 3.4/3.8 mm), surrounding the injection site. Fibers emerging from AAV1/2 -transduced cells reached the lesion border, many of them entered the lesion and occasionally went across the scar, whereas fibers of AAV5-transduced cells faded in a proximity of 300 µm to it. Dorsoventrally, cellular eGFP signal was detected in a gray matter of the subjects transduced with both serotypes, whereas only AAV5 - mCMV transduced cells also in a white matter. Morphology of eGFP expressing cells indicated that both serotypes transduced interneurons and large neurons of Lamina IX. IHC documented that AAV5 and, to a lesser extent, AAV1/2, transduced cholinergic cells (VAChT), whereas none of the transduced neurons were GABAergic (GAD67) or glutamatergic (VGLUT2). AAV5 transduced also glial cells, some identified as astrocytes (GFAP). In conclusion, both vectors efficiently transduce neurons in spinal animals; mCMV promoter drives eGFP expression also in glia. Support: Polish-German Project PBZ-MIN-001/P05/13, S007/PN/2007/01and statutory grant to Nencki Institute.