小鼠胃癌模型的建立及T细胞免疫功能的变化

Mouse model of gastric cancer and changes of T cell immune function

目的通过多因素联合攻击法建立小鼠原发胃癌模型并检测其免疫功能水平的变化。方法采用BALB／C小鼠以3-甲基胆蒽（3-MCA）挂线法联合N-甲基-N-亚硝基脲（MNU）灌胃法诱导小鼠胃癌。于12周及20周取血及脾细胞检测其CD4＋CD25＋调节性T细胞（CIM＋CD25＋TregCells）及T细胞亚群，同时取胃标本行病理学检查，通过统计学方法分析结果。结果多因素联合攻击法诱导率为37．5％（6／16），实验组小鼠（4．52±1．97）g体质量变化有所降低（P〈0．05）。脾白细胞计数（372±140）×10^9升高（P〈0．05）。外周血（8．07±6．62）％及脾（6．45±4．13）％CD4＋CD25＋Treg细胞比例均升高（P〈0．05），脾CD4＋／CD8＋细胞比值（1．95±0．62）明显升高（P〈0．05）。结论多因素联合攻击法为小鼠胃癌为小鼠胃癌模型建立提供了良好的模型。小鼠胃癌发展过程中CD4＋CD25＋Treg细胞呈高表达，且在肿瘤形成后免疫功能呈现免疫抑制状态。

Objective To induce gastric cancer mouse model using 3-methylcholanthrene and N- methyl-N-nitrosourea and to assess the characteristics of the immune system during model construction. Methods BALB/c mice were used to establish gastric cancer model. Glandular stomach of the mice was sutured with 3-MCA-containing silk suture, and subsequent intragastric administration of MNU was done to induce gastric cancer. On the week 12 and 20, peripheral blood and splenocytes were tested for WBC count, and CD3＋ , CD4＋ , and CD8＋ T-cell subsets and CD4＋ CD25 ＋ Treg cells were assessed by flow cytometry with concurrent collection of mice stomachs for pathologic study. Data collected were then analyzed statistically. Results Cancer inducing rate with multiple factors attack method was 37. 5% （6/16）, and weight changes in test group [ （4. 52 ± 1.97） g] significantly decreased （P 〈0. 05）, and the levels of Treg cells in peripheral blood [ （8. 07 ±6. 62） % ] and [spleen （6. 45 ±4. 13） % ] both showed significant increase （P 〈 0.05）, while CD4＋/CD8 ＋ ratio only showed significant increase in the spleen （ 1.95±0. 62,P 〈 0. 05 ）. Conclusion Multiple factors attack method successfully induced gastric cancer in mice. Treg cells showed high expression during progress of gastric cancer, and after tumor formation there was suppression of the immune functions.