儿童接种新甲型（H1N1）流感疫苗后特异性CD4＋T细胞亚群的表型特征

Characterization of CD4 ＋ T cell after immunization with HIN1 influenza vaccine for children

目的探讨儿童接种新甲型（H1N1）流感疫苗接种后远期疫苗特异性CD4＋记忆T细胞亚群的特征。方法根据自愿原则，选择31例接种甲型H1N1流感疫苗47个月后的儿童，取静脉血并分离淋巴细胞，细胞培养中滴入甲型H1N1流感疫苗，同时设不加疫苗刺激的作为对照组，流式细胞仪检测CD4＋记忆T细胞亚群的表型特征。结果外周血单个核细胞（PBMC）中CD4＋疫苗特异刺激组为29．85％，对照组为39．00％，实验组低于对照组；CD4＋初始T细胞实验组为74．32％，对照组为70．08％（P〉0．05）；CD4＋记忆T细胞实验组为28．54％，与对照组25．52％比较，无统计学意义（P〉0．05）；记忆T细胞分中央型与效应型记忆T细胞，检测结果：CCR7和CD62L单阳性记忆T细胞亚群实验组分别为72．52％、29．85％，对照组分别为84．0％、93．44％，实验组的明显低于对照组（P〈0．05）。结论实验儿童初始T细胞比例都较高；甲型H1N1流感疫苗能诱导抗原特异性记忆CD4＋T细胞的产生，可是为数较少，当中主要是中央型记忆CD4＋T细胞，其中CCR7＋和CD62L＋记忆T细胞数量较低。

Objective To explore the characteristics of CD4＋ memory T cell in children with influenza A （H1 N1 ） vaccination. Methods According to the voluntary principle, 31 children with influenza A （H1N1 ） vaccination for over 47 months were selected. Their lymphocytes were isolated and joined with the influenza A （H1N1） vaccine for cultivation,which was taken as the experimental group, and the control group was treated with no vaccine. The flow cytometry was used to detect the expression of cell surface molecules. Results The results showed that the proportion of CD4＋ T cells in PBMC was 29. 85% in the experimental group and 39.00% in the control group;the proportion in the experimental group was lower than that in the control group. The proportions of CD4＋ naive T cells in the experimental group and in the control group were both more than 70% （ P 〉 0.05） ; the proportion of CD4＋ memory T cells in the experimental group was 28.54% and 25.52% in the control group（ P 〉 0.05 ）. Memory T cells were divided into central and effector memory T cells. Detection results of two subsets：The proportions of CCR7 and CD62L single positive memory T cell subsets in the experi- mental group were 72.52% and 29.85% ,respectively,their proportions in the control group were 84.0% and 93.44% ;the proportions in the experimental group were significantly lower than those in the control group （ P 〈 0.05）. Conclusion This study shows that CD4＋ T cells are dominant cells in 31 children, and the pro- portion of naive T cells （CD45RA ＋ ） is high. H1N1 influenza vaccine can induce production of antigen-specific memory CD4＋ T cells, but few in number;wherein, most of them are central memory CD4＋ T cells, furthermore, the numbers of CCR7 and CD62L single positive memory T cells are small.