Attenuation of Stroke Size in Rats Using an Adenoviral Vector to Induce Overexpression of Interleukin-1 Receptor Antagonist in Brain

Adenoviruses have been proposed as potential vectors for gene therapy in the central nervous system, but there are no reports of their use in the treatment of a brain disease. Because central administration of interleukin-1 receptor antagonist protein (IL-1ra) reduces ischemic brain damage, we determined whether a recombinant adenovirus vector carrying the human IL-1ra cDNA (Ad.RSV IL-1ra) could be used to ameliorate brain injury in permanent focal ischemia. Groups of six rats received intraventricular injections of Ad.RSV IL-1ra or a control adenovirus containing the Escherichia coli β-galactosidase gene (Ad.RSV lacZ). Histochemical staining for β-galactosidase 5 days after virus injection indicated that transgene expression was confined primarily to the cells lining the ventricle. The concentrations of IL-1ra were fivefold to 50-fold higher in the Ad.RSV IL-1ra-injected animals, achieving levels of 9.1 ± 3.3 ng/g in brain and 23.7 ± 22.5 ng/ml in CSF. In these animals, cerebral infarct volume resulting from 24 h of permanent middle cerebral artery occlusion was reduced 64%. These studies demonstrate that adenoviral vectors can be used to deliver genes that attenuate brain injury.