Induction of potent anti-tumor immunity by direct injection of Ad-LIGHT at the site of tumor inoculation

Abstract

The aim of this study was to observe the therapeutic effects of adenovirus-mediated LIGHT gene transfer in murine B16 melanoma in vivo. C57BL/6 mice were inoculated subcutaneously with B16 cells to establish the murine melanoma model. The tumor-bearing mice were injected at the site of tumor inoculation with recombinant adenoviral vectors expressing the murine LIGHT gene. The tumor growth and survival period of tumor-bearing mice were observed. The splenic NK and CTL activity were measured in vitro by lactate dehydrogenase (LDH) release assay. The amounts of cytokines were determined with ELISA kits. The LIGHT gene could be efficiently transduced into tumor tissue after injection of Ad-LIGHT. Treatment with Ad-LIGHT significantly inhibited the tumor growth and prolonged the survival period of the tumor-bearing mice. The splenic NK and CTL activity of the mice was also enhanced after LIGHT gene transfer. The production of IL-2 and IFN-gamma from lymphocytes derived from mice treated with Ad-LIGHT was increased significantly compared with control groups. Our results indicate that local expression of the LIGHT gene can induce potent anti-tumor immunity and may be a promising treatment strategy for melanoma.