CD4＋CD25＋调节性T细胞表达水平对Th1／Th2类细胞免疫平衡的作用及与HBV宫内感染的相关性

摘要

目的：探讨孕妇外周血及新生儿脐血中 CD4＋CD25＋调节性 T细胞（CD4＋CD25＋Treg）表达水平对 Th1/Th2类细胞免疫平衡的作用及与 HBV宫内感染的相关性。方法选择 HBsAg阳性但肝功能正常的单胎足月妊娠未临产孕妇101例及其新生儿101例，根据脐血的检验结果将8例发生 HBV宫内感染的新生儿及其母亲纳入研究组（n＝16），将93例未发生 HBV宫内感染的新生儿及其母亲纳入对照组（n＝186）。采用流式细胞仪检测CD4＋CD25＋Treg和 ELISA法检测各组干扰素-r（IFN-γ）及白介素-4（IL-4）水平。结果研究组中孕妇外周血和新生儿脐血的 IFN-γ及 IFN-γ/IL-4均明显低于对照组（P＜0．05）；且 IL-4及CD4＋CD25＋Treg占 CD4＋淋巴细胞百分比都明显高于对照组（P＜0．05）。研究组和对照组中孕妇外周血及新生儿脐血的CD4＋CD25＋Treg与IFN-γ、IFN-γ/IL-4呈负相关（P＜0．01，P＜0．05），与 IL-4呈正相关（P＜0．01，P＜0．05）。结论 HBV宫内感染时，孕妇和新生儿Th1型特异性反应降低而Th2型特异性反应增强，Th1/Th2间的细胞免疫失衡可能是促使 HBV宫内感染的机制之一。HBV宫内感染与孕妇外周血和新生儿脐血中 CD4＋CD25＋Treg 的分泌水平升高有关，CD4＋CD25＋Treg水平的升高可能是发生 HBV宫内感染的高危因素之一。%Objective To investigate the effects of maternal blood and neonatal cord blood CD4+ CD25+ regulatory T(Treg)cells on Th1/Th2 balance and their relationships to hepatitis B virus(HBV)intrauterine infection.Methods According to the results of umbilical cord blood tes-ting,101 HBsAg-positive women with singleton full term pregnancy and normal liver function and their newborns were divided into two groups:study group(8 newborns with HBV intrauterine in-fection and their mothers)and control group(93 newborns without HBV intrauterine infection and their mothers).CD4+ CD2 5+ Treg cells were detected by flow cytometry and IFN-γand IL-4 levels were measured by ELISA.Results Compared with control group,maternal blood and neo-natal cord blood levels of IFN-γand IFN-γ/IL-4 significantly decreased but IL-4 levels and per-centage of CD4+ CD25+ Treg cells accounting for CD4+ lymphocytes significantly increased in study group(P<0.05).The percentage of CD4+ CD25+ Treg cells were negatively correlated with levels of IFN-γand IFN-γ/IL-4,but positively correlated with levels of IL-4(P<0.01 or P<0.05).Conclusion Specific Th1 response decreases but Specific Th2 response increases in HBV intrauterine infection.Th1/Th2 imbalance is one of the possible mechanisms responsible for HBV intrauterine infection.In addition,HBV intrauterine infection is correlated with the increase in maternal blood and neonatal cord blood CD4+ CD25+ Treg cells,which may be a major risk fac-tor for HBV intrauterine infection.