Tatad A M Francesca, Nesin Mirjana, Peoples John, Cheung Sandy, Lin Hong, Sison Cristina, Perlman Jeffrey, Cunningham-Rundles Susanna
Department of Pediatrics, Host Defenses Program, Weill Cornell Medical College, Manhasset, NY 10021, USA.
Neonatology. 2008;94(1):8-15. doi: 10.1159/000112541. Epub 2007 Dec 19.
Neonatal susceptibility to bacterial infection is associated with an immature immune system, but the role of different bacterial antigens in specific responses is largely unknown.
To evaluate differences in intracellular cytokine response to physiologically relevant bacterial antigens in term and preterm infants as compared with adults.
Cord blood samples from preterm and term neonates and adult peripheral blood samples were cultured ex vivo with and without whole heat-killed bacteria. Intracellular leukocyte production of interleukin (IL)-6, IL-10, IL-12, and IL-8 responses was assessed by flow cytometry.
Monocytes were the primary producers of all mediators. Escherichia coli was the most potent stimulant. Lactobacillus plantarum 299v activated fewer monocytes as compared with E. coli for all responses (p < 0.05), except for IL-12 in term neonates. IL-6 response to Staphylococcus epidermidis was lower in both groups of neonates as compared with adults (p = 0.023 and p = 0.001). IL-8 response to S. epidermidis was lower in term as compared with preterm neonates and adults (p = 0.003). IL-10 response to group B streptococci was lower in term neonates as compared with adults and higher in preterm as compared with term neonates (p = 0.015).
Monocytes from term neonates compared to preterm neonates show a downregulated anti-inflammatory response to specific bacteria. High neonatal response to pathogenic E. coli in the preterm infant could cause uncontrolled inflammatory response, while lower IL-6 response to S. epidermidis in neonates may indicate a basis for vulnerability to S. epidermidis infection.
新生儿对细菌感染的易感性与免疫系统不成熟有关，但不同细菌抗原在特异性反应中的作用很大程度上尚不清楚。
评估足月儿和早产儿与成人相比，对生理相关细菌抗原的细胞内细胞因子反应的差异。
将早产儿和足月儿的脐血样本以及成人外周血样本在有或无全热灭活细菌的情况下进行体外培养。通过流式细胞术评估白细胞介素（IL）-6、IL-10、IL-12和IL-8反应的细胞内产生情况。
单核细胞是所有介质的主要产生者。大肠杆菌是最有效的刺激物。与大肠杆菌相比，植物乳杆菌299v激活的单核细胞在所有反应中均较少（p < 0.05），足月新生儿的IL-12反应除外。与成人相比，两组新生儿对表皮葡萄球菌的IL-6反应均较低（p = 0.023和p = 0.001）。与早产儿和成人相比，足月儿对表皮葡萄球菌的IL-8反应较低（p = 0.003）。与成人相比，足月新生儿对B族链球菌的IL-10反应较低，与足月新生儿相比，早产儿的反应较高（p = 0.015）。
与早产儿相比，足月儿的单核细胞对特定细菌的抗炎反应下调。早产儿对致病性大肠杆菌的高反应可能导致不受控制的炎症反应，而新生儿对表皮葡萄球菌的IL-6反应较低可能表明其易患表皮葡萄球菌感染的基础。
