Anti-angiogenesis effect on glioma of attenuated Salmonella typhimurium vaccine strain with flk-1 gene

To investigate the anti-vasculature effects and the anti-glioma effects of attenuatedSalmonella typhimurium vaccine strain expressing VEGFR2 (flk-1) gene, plasmid pcDNA3, 1-flk1 was constructed and electro-transfected into live attenuatedSalmonella typhimurium strain SL7207. Mouse models of intracranial Gl261 glioblastoma were treated with an orally administered attenuatedSalmonella typhimurium expressing flk-1 gene. The survival period was recorded and vessel density was observed by immunofluorescence. CTLs activity was measured by MTT assay. Our results showed that attenuatedSalmonella typhimurium vaccine strain expressing flk-1 gene could significantly inhibit glioblastoma growth, reduce vessel density, prolong the survival period and improve the survival rate in these mice. The flk-1 specific CTLs activity was increased obviously after the vaccination. Our study showed that attenuatedSalmonella typhimurium vaccine strain expressing flk-1 gene could break peripheral immune tolerance a in glioma gainst this self-antigen and kill endothelial cells by the orally administered vaccine and can be used for both prophylactic and therapeutic purposes.