NOD样受体介导炎症反应在不同胎龄及出生体重早产儿抗感染免疫中的作用和意义

目的比较不同胎龄及出生体重早产儿NOD样受体(NOD1和NOD2)和炎症因子IL-6、TNF-α表达的差异,分析早产儿胎龄及出生体重与免疫功能的关系。方法收集2016年4月-2017年11月苏州大学附属儿童医院新生儿科收治的早产儿外周血标本,分离早产儿外周血单个核细胞,分别加入NOD1激动剂Tri-DAP、NOD2激动剂MDP刺激细胞24h,测定细胞中NOD1、NOD2的基因水平以及上清液中IL-6、TNF-α的表达水平。结果胎龄<32周的早产儿NOD1mRNA及IL-6的表达量明显低于34～36周早产儿(P<0.05);出生体重<1.5kg的早产儿NOD1mRNA的表达量明显低于1.5kg以上的早产儿、NOD2 mRNA以及IL-6的表达明显低于2.0～2.5kg的早产儿(P<0.05);NOD1mRNA、NOD2mRNA的表达量与出生体重呈正相关(r=0.352、0.306,P<0.05),但与胎龄无明显相关性;TNF-α的表达与胎龄和出生体重均呈正相关(r=0.380、0.289,P<0.05)。结论出生体重越低,早产儿NOD样受体水平越低,介导抗感染免疫也越弱。相比于胎龄,出生体重对早产儿免疫功能影响较大。

Role and significance of NOD-like receptor mediated inflammatory response in anti-infection immunity of preterm infants

Objective To compare the difference of the expression of NOD-like receptors (NOD1 and NOD2), IL-6 and TNF-α in preterm infants in different gestational age and birth weight groups, in order to analyze the relationship among gestational age, birth weight and immune function in preterm infants. Methods Blood samples of preterm infants in the neonatal department of Childerns Hospital of Soochow University were collected from April 2016 to January 2017. The peripheral blood mononuclear cells of the preterm infants were collected, and were stimulated for 24 hours by Tri-DAP and MDP.The expression levels of NOD1 and NOD2 gene in the cells and IL-6, TNF-α in the supernatant were tested. Results The expression levels of NOD1 mRNA and IL-6 in preterm infants with gestational age<32 weeks were significantly lower than those with gestational age of 34-＜36 weeks (P<0.05).The expression of NOD1 mRNA in preterm infants with birth weight<1.5 kg was significantly lower than those with birth weight over 1.5 kg.And the expression of NOD2 mRNA and IL-6 was significantly lower than that with 2.0-2.5 kg (P<0.05).Moreover, the levels of NOD1 mRNA and NOD2 mRNA were positively correlated with birth weight(r=0.352,0.306,P<0.05), but were not related to gestational age.The expression of TNF-α was positively correlated with both gestational age and birth weight(r=0.380,0.289,P<0.05). Conclusions Preterm infants with lower birth weight has lower levels of NOD-like receptor and poorer immunity to infection.Birth weight has greater influence on immune function in premature infants compared with gestational age.