滤泡辅助性T淋巴细胞在麻疹患儿中的表达及在免疫应答中的作用

Expression of T follicular helper cells and its role in immune responses in children with measles

目的 探讨滤泡辅助性T淋巴细胞（TFH）在麻疹患儿中的表达及其在免疫应答中的作用.方法 连续采集2013年4至9月浙江省宁波市北仑区人民医院收治的60例麻疹患儿急性期全血和血清样本,选择同期体检儿童17名作为对照组.利用流式细胞术检测麻疹患儿和健康体检儿童外周血中的TFH频数,并用酶联免疫吸附试验（ELISA）检测血清中麻疹病毒IgM和IgG的抗体含量.两组TFH频数比较采用t检验,麻疹患儿血清中IgM、IgG抗体水平与TFH所占频数的相关性分析采用Pearson法.结果 麻疹组和对照组CD4＋ CXCR5＋细胞占CD4＋T淋巴细胞的频数分别为（8.923 ±0.665）％和（4.274 ±0.182）％,两组之间差异有统计学意义（t=2.751,P＜0.01）.以CD4＋T淋巴细胞射门,麻疹组中CXCR5和ICOS双阳性细胞频数,CXCR5和PD-1双阳性细胞频数分别为（1.075 ±0.107）％和（0.656±0.074）％,对照组中则分别为（0.456±0.068）％和（0.224±0.017）％,麻疹组高于对照组（t=2.169和2.968,P值均＜0.05）.Pearson分析结果显示,麻疹患儿TFH所占频数与IgM抗体水平呈正相关（r=0.490,P＜0.05）.结论 TFH在麻疹病毒感染引起的特异性麻疹抗体的产生中发挥重要作用.

Objective To investigate the expression of T follicular helper cells （TFH） in children with measles,and to identify the role of TFH in immune response.Methods The whole blood and serum samples from 60 children with measles in acute stage were collected from April to September 2013 in Beilun District People＇s Hospital.Seventeen healthy children were also enrolled as the controls.The frequency of TFH in peripheral blood was detected by flow cytometry,and serum levels of IgM and IgG were measured with enzyme linked immunosorbent assay （ELISA）.t test was used to compare the frequencies of TFH between measles and control groups,and Pearson correlation analysis was performed to reveal the correlations of IgM and IgG levels with the frequency of TFH.Results The frequencies of CD4 ＋ CXCR5 ＋ TFH in CD4 ＋ T cells was （8.923 ±0.665）％ in measles group,which was higher than that in control group （4.274 ± 0.182）％,and the difference was of statistical significance （t =2.751,P ＜ 0.01）.Gating in CD4 ＋ T cells,the frequencies of CXCR5 ＋ ICOS ＋ TFH and CXCR5＋ PD-1 ＋ TFH in measles group were （1.075 ± 0.107）％ and （0.656 ±0.074）％,while those in control group were （0.456 ±0.068）％ （t =2.169,P＜ 0.05） and （0.224 ± 0.017）％ （t =2.968,P ＜ 0.05）.Pearson correlation analysis showed that the frequency of TFH was positively correlated with the serum level of IgM （r =0.490,P ＜ 0.05）.Conclusion TFH in peripheral blood may facilitate the production of measles-specific antibodies during measles virus infection.