儿童新甲型流感疫苗远期特异性CD8^+记忆T细胞的表型特征

Characterization of naive and memory T cell after immunization with H1N1 influenza vaccine for children

目的:探讨儿童新甲型(H1N1)流感疫苗接种后远期外周血疫苗特异性CD8^+记忆T细胞的特征。方法:选择31例于2009年12月~2010年1月接种甲型H1N1流感疫苗的3~6岁儿童,抽取外周静脉血5 ml,分离淋巴细胞加入甲型H1N1流感疫苗进行培养,并设对照组,用流式细胞仪检测细胞表面分子的表达,同时以CCK-8法检测细胞增殖,计算细胞增殖指数。结果:外周血PBMC中CD8^+T细胞在实验组和对照组分别是13.41%与9.41%,P>0.05。CD8^+初始T细胞在两组的比例均高达80%上;CD8^+记忆T细胞在两组占17%~19%;记忆T细胞分中央型和效应型记忆T细胞,两个亚群检测结果:CCR7和CD62L单阳性记忆T细胞亚群在实验组占比明显低于对照组的占比,P<0.05。应用CCK-8法检测疫苗刺激后抗原特异性增殖,检测结果见细胞增殖指数大于0.8的仅为51.16%,大于1.0在本研究中没有。结论:31例儿童外周血PBMC中CD8^+T细胞占比少,初始T细胞CD45R+均较高,具有抗原再刺激后再应答的基础;甲型H1N1流感疫苗可以诱导抗原特异性记忆CD8^+T细胞的产生,但数量不多,其中大多数为中央型记忆CD8^+T细胞;细胞增殖指数结果表明疫苗特异性细胞增殖不佳;提示对该疫苗的远期疫苗特异性CD8^+T细胞免疫记忆不理想。

Objective： To elucidate the characterization of CD8^＋T cell in H1N1 influenza vaccine for children. Methods： PBMCs were isolated from 31 children aged from 3 to 6 years old who had accepted H1N1 influenza vaccine during December 2009 to January 2010. The lymphocytes were joined with the H1N1 influenza vaccine as experimental group and cultured. The experiment set without vaccine group as control group. At last we detected the surface molecules by FCM. The CCK-8 assay was added to detecting cellular proliferation and cellular proliferation index were detected by CCK-8. Results： CD8^＋T cells of PBMC in the two groups were 13. 41%and 9. 41%,P〈0. 05. CD8^＋CD45RAA^＋naive T cells in the two groups were up to more than 80%,P〈0. 05. The proportion of CD8^＋CD45ROA^＋memory T cells in two groups were up to 17%-19%,P〈0. 05. Two subsets of CD8^＋CD45ROA^＋memory T cells ： CCR7^＋and CD62L^＋single positive memory T cell subsets in the experimental group were significantly lower than that of the control group,P〈0. 05. The CCK-8 assay was added to detect cellular proliferation. Only 51. 16% of which cellular proliferation index was greater than 0. 8,with none was greater than 1 in this study. Conclusion： This study showed that the CD4^＋T cells were low-level,naive T cells（ CD8^＋CD45RAA^＋） were higher,with antigen stimulation and response. H1N1 vaccination specific memory T cells were few in number,specific memory T cell subsets were diversity,control memory cells were the main phenotypic characteristics. Cellular proliferation index showed that the proliferation of specific CD8^＋T cells vaccine was poor.