OBJECTIVETo construct recombinant adenoviruses expressing antiangiogenic fragment of human thrombospondin1 (TSP1f).

METHODSTSP1f cDNA was amplified by RT-PCR from normal human peripheral blood mononuclear cells and was subcloned into a shuttle vector pShuttle-CMV. After sequence confirmation, the resultant plasmid was linearized by the restriction endonuclease Pme I and cotransformed with the supercoiled adenoviral vector pAdEasy-1 into Escherichia coli strain BJ5183. Recombinants were selected by Kanamycin resistance and screened by restriction endonuclease digestion. Then, the recombinant adenoviral construct was cleaved with Pac I and transfected into the packaging cell line 293. The adenoviral vector ADV-TSP1f was propagated in 293 cells and purified by cesium chloride (CsCl) density centrifugation. PCR and Western blot analysis were performed to confirm TSP1f expression.

RESULTSOf 43 Kanamycin-resistant colonies obtained from cotransformation, all of the 10 smallest ones were the correct recombinants. TSP-1f was expressed efficiently by ADV-TSP1f. The virus stock titer after CsCl banding was 1.0 x 10(11) pfu/mL.

CONCLUSIONSGenerating recombinant adenoviruses using AdEasy System results in highly efficient viral production and significantly decrease the time required to construct usable viruses. ADV-TSP1f can be further used in in vivo gene therapy studies.