Inhibitory Effects of the AttenuatedSalmonella typhimuriumContaining the IL-2 Gene on Hepatic Tumors in Mice

Abstract

To observe the inhibitory effects of an attenuatedS. typhimuriumstrain carrying IL-2 gene (TPI) on hepatoma cell line (HepG2) and transplanted tumors in mice. TPI, TPG (an attenuatedS. typhimuriumstrain carrying green fluorescent protein gene), and TP (an attenuatedS. typhimuriumstrain) strains were transfected into HepG2 cells. At 48h after transfecting, the transfection rate was 82.58 ± 1.74%. The expression level of IL-2 was (99.5 ± 12.2) ng/1×106cells. Compared with TPG, TP, and normal mouse groups, the proportion of CD4+T and CD8+T cells in the blood from the TPI group was higher, the levels of IgM and IgG1were significantly increased, and the proliferation activity of splenic lymphocyte was significantly stronger. The transplanted tumor weight in the TPI group was significantly smaller than that in the other two groups. The infiltration of lymphocytes increased in the tumor from TPI group mice. TPI was effectively transfected into cancer cells, which expressed the protein of interest. Oral administration of TPI prolonged survival of mice transplanted with hepatoma cell tumours.