老年小鼠对Lewis肺癌敏感性及T细胞亚群差异观察

Differences in susceptibility to Lewis lung carcinoma and T lymphocyte subsets of aged mice

目的探讨青年和老年小鼠对Lewis肺癌成瘤敏感性及其免疫微环境T细胞亚群的差异。方法青年（2月龄）与老年（12月龄）小鼠各6只，分别在左腋下注射1×10 6个Lewis细胞，观察青年与老年小鼠体重及肿瘤生长情况；24d后取血进行血常规检测，用流式检测脾脏CD4＋、CD8＋T细胞比例以及肿瘤微环境中浸润CD4＋、CD8＋T细胞及相关效应T细胞比例。结果老年组体重明显高于青年组（P〈0．001），老年和青年小鼠的瘤重分别为（5．084±0．528）g和（2．963±0．378），差异具有统计学意义（t=3．349，P=0．012）；血常规指标检测显示，老年组白细胞及亚群（除单核外）数量明显低于青年组（P〈0．05）；流式结果显示，老年组脾脏的效应和记忆效应CD4＋T细胞比例均明显高于青年组（P〈0．001）；且肿瘤微环境的效应和记忆效应CD8＋T细胞表达也均明显高于青年组（P〈0．05）；CBA检测结果显示，老年组和青年组肿瘤微环境中IL-6、IL-10的相对平均荧光程度值分别（25090±3820，10670±1793）、（6252±864，3061±451），且老年组的表达明显低于青年组（t=3．925，P=0．01；t=3．552，P=0．02）。结论青年小鼠Lewis肺癌的生长比老年小鼠更快，原因之一可能由于炎症与免疫系统的差异导致。

Objective To investigate the differences in susceptibility to Lewis lung carcinoma and T lymphocyte subsets in the immune microenvironment between young and elderly mice. Methods Six C57/B6 mice at two months（young）and six mice at twelve months（aged）were injected with Lewis lung carcinoma cells at the dose of 1 × 10^6 in the left armpit to establish a murine model of lung carcinoma. The weight and tumor growth were monitored. Blood samples for routine blood tests were collected after 24 days. The proportions of CD4＋ and CD8＋ T cells in the spleen were detected by flow cytometry,and the infiltration of CD4＋ ,CD8＋ T cells and related effector T cells in the tumor microenvironment were determined in the same way. Results The body weight of tumor bearing mice in the aged group was significantly higher than that in the young group（P 〈0. 001） ;The tumor weight in the aged group（5. 084±0. 528）g was significantly higher than that in the young group（2. 963 ±0. 378）g（t = 3,349,P = 0. 012）;Routine blood tests showed that the numbers of leukocytes and subsets（except mononuclear）in the aged group were significantly lower than in the young group（P〈0.05） ;Flow eytometry found that the effector and memory/effector CD4＋ T cell ratios in the spleen were significantly higher in the aged group than in the young group（P 〈0. 001）and the expression of effeetor and memory/effector CD8＋T cells in the tumor microenvironment was also significantly higher than in the young group（P〈0.05）;Quantitative expression values of IL-6 and IL-10 in the tumor microenvironment were 25090±3820 and 10670± 1793 in the aged group and 6252±864 and 3061± 451 in the young group, respectively. Moreover, the expression levels of IL-6 and IL-10 （t = 3. 925,P = 0.01;t = 3. 552,P = 0.02） in the tumor microenvironment in the aged group were significantly lower than those in the young group. Conclusions Young mice are more susceptible to Lewis lung carcinoma, probably as a result of differences in inflammation and immunity.