Promoter selectivity targets transgene expression to specific neural cell types <i>in vitro</i> and in the adult brain.

<p>AAV vectors (1×10⁹ vg) were used to express GFP driven by the indicated promoters in enriched primary oligodendrocyte cultures (A–C). For in vivo studies vectors (2×10⁹ vg) were injected in the striatum of adult mice (D–F). Representative images of results by double-immunocytochemistry for GFP (green) and cell-type specific markers (red) illustrate promoter selectivity. A, In primary cultures AAV-CBA-GFP expressed in all NeuN⁺ neurons. In addition, NeuN-negative astrocytes (top in picture) showed GFP immunoreactivity. B, AAV-MBP-GFP-mediated GFP-expression was restricted to ASPA⁺ oligodendrocytes in vitro. C, AAV-GFAP-GFP transduction resulted in GFP immunoreactivity limited to cultured GFAP⁺ astrocytes. D, CBA promoter-controlled GFP expression was highly specific to neurons in vivo. E, The MBP promoter was selective for forebrain oligodendrocytes. F, The GFAP promoter drove GFP specifically in astrocytes. Representative results from three independent experiments are shown. Bars: A–C, 50 µm; D–F, 100 µm.