宫内炎症暴露对早产儿固有免疫应答的影响

摘要

Objective To explore the effect of in utero exposure to inlfammation on innate immune response in preterm infants. Methods Forty-seven premature infants with gestational age<35 weeks were recruited in this study. According to his-tological evidence of placental infection, all neonates were divided into intrauterine inlfammation positive group and negative group. Mononuclear cells and monocytes were isolated from umbilical cord blood, and were cultured in vitro in the presence or absence of LPS (100 ng/ml). The levels of interleukin 1β(IL-1β), interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α) and interleukin 10 (IL-10) in cord blood plasma and monocyte cultural supernatants were measured by ELISA respectively. The level of IL-1β, TNF-α, IL-6 and IL-10 mRNA were detected by Real-time PCR. Expression of HLA-DR on surface of CD14+monocytes and ratio of CD3+CD4+/CD3+CD8+T was analyzed by lfow cytometry. Results (1) The level of cord plasma IL-6 in intrauterine inlfammation positive group was signiifcantly higher than in negative group. (P=0.02). (2) After stimulation of LPS, levels of IL-1β, IL-6, TNF-α, IL-10 in supernatants were increased signiifcantly, in consistence with their mRNA expression (P<0.05) in both groups. (3) Expression of HLA-DR on surface of monocytes was signiifcantly decreased after stimulation with LPS in intrauterine inlfammation positive group (P=0.012), but was signiifcantly increased in negative group (P=0.0305). Con-clusions In utero exposure to inlfammation does not suppress the response of monocytes to LPS in preterm neonates, but impairs the antigen presenting function in monocytes.%目的：探讨宫内炎症暴露对早产儿固有免疫应答的影响。方法2013年6月至2014年6月出生、胎龄<35周的早产儿47例纳入本研究。依据胎盘病理检查结果，将早产儿分为宫内炎症阳性组和阴性组。采用Ficoll密度梯度离心法和贴壁黏附法分别获得脐血单个核细胞以及单核细胞。用内毒素(LPS，100 ng/ml)刺激单个核细胞12 h后，流式细胞术(PCR)检测CD14+单核细胞HLA-DR的表达量以及CD3+CD4+/CD3+CD8+的比例。用LPS(100 ng/ml)刺激单核细胞6 h后，Real-Time PCR检测单核细胞IL-1β、IL-6、IL-10、TNF-αmRNA表达量的变化。ELISA检测脐血以及单核细胞培养上清液中IL-1β、IL-6、IL-10和TNF-α水平。结果宫内炎症阳性组脐血血浆IL-6水平高于宫内炎症阴性组，差异有统计学意义(P=0.001)。LPS刺激后，两组单核细胞IL-1β、IL-6、IL-10、TNF-α mRNA表达量及培养上清液中蛋白水平均显著升高，与刺激前比较差异均有统计学意义(P<0.05)；但两组间比较差异均无统计学意义(P>0.05)。LPS刺激后，宫内炎症阳性组CD14+单核细胞HLA-DR表达量显著降低，而宫内炎症阴性组则显著升高，与刺激前比较差异均有统计学意义(P<0.05)；且阳性组HLA-DR表达量显著低于阴性组(P=0.002)。结论宫内炎症暴露并不影响早产儿脐血单核细胞对LPS的应答反应水平，但可抑制单核细胞激活后主要抗原递呈受体的表达。