Interleukin 15 gene therapy mouse model of gastric carcinoma

Objective To establish mouse model of gastric carcinoma,and assess the effects of tumor-bearing state on the immune system and the therapeutic and preventive effects of interleukin 15 ( IL-15 ) gene therapy.Methods Six-week-old male BALB/C mice were utilized to establish gastric cancer model through multiple carcinogens attack.Gastric specimens were collected for pathologic study at the 20th week,and peripheral blood and splenocytes were tested for T-cell subsets and Treg by flow cytometry.NK cell cytotoxicity was assessed to evaluate the effect of IL-15 gene therapy on gastric cancer,and data were analyzed statiscally.Results 37.5％ of mice were successfully induced with gastric carcinoma on the week 20.Compared to the other two groups,IL-15 expression (9.20 ± 2.92 ) ng/L and NK cell cytotoxicity (216.91±117.80) U/L in cancer-induced group were significantly decreased ( P＜0.05).Periphpearl blood Treg expression was significantly increased in the cancer-induce group ( 8.07 ± 6.62 ) ％,while spleenocyte Treg expression was significantly decreased in the control group [(4.40 ± 3.34)％,P ＜0.05].There was no significant difference in T cell subsets in the peripheral blood among the group ( P ＞0.05 ),but in cancer-induced group the number of spleenocyte CD3 + T cells (78.31 ± 29.79) ％ was significantly increased ( P ＜0.05 ),while that of CD4+ T cells(19.98 ±5.77)％ and CD8+ T cells ( 10.15±1.72) ％ was significantly decreased ( P ＜ 0.05 ).Conclusion Multiple carcinogens attack was an ideal way to establish mouse model of gastric carcinoma in mice.During tumor-bearing state,there was a significant decrease in immune function,and immunogene therapy with IL-15 plasmid vector can enhance immune function to achieve anti-tumor immune response. Key words: Gastric carcinoma; Immunogene therapy; Interleukin-15; T-Cell subset