新生儿中性粒细胞非髓过氧化物酶介导系统活性的研究

Non-myeloperoxidase-mediated system activity of neutrophil in newborn infants

目的 探讨细菌感染状态下 ,新生儿中性粒细胞非髓过氧化物酶 (non myeloperoxidase,NMPO)介导系统活性的变化 ,以及脐带血血浆对NMPO介导系统激活的影响。方法 利用佛波醇乙酯 (phorbol1 2 myristate 1 3 acetate ,PMA)、金黄色葡萄球菌和大肠埃希菌刺激脐带血中性粒细胞 ,并将脐带血的血细胞或血浆与成人外周血的血细胞或血浆进行交叉混合 ,结合荧光染色 流式细胞仪技术检测NMPO介导系统的活性。结果 利用PMA刺激 ,以模拟非感染状态下NMPO介导系统的激活 ,新生儿脐带血中性粒细胞的NMPO介导系统的活性与成人相比明显低下 (t=3 378,P <0 0 1 )。利用金黄色葡萄球菌和大肠埃希菌刺激 ,以模拟感染状态下NMPO介导系统的激活 ,新生儿脐带血NMPO介导系统的活性均表现为低下 ,但是在大肠埃希菌刺激时表现的更明显 (t=1 2 1 50 ,P <0 0 0 1 )。同时 ,在利用大肠埃希菌刺激时 ,脐带血血浆可以明显地抑制NMPO介导系统的活性 ,表现为混合了脐带血血浆的新生儿脐带血和成人外周血中性粒细胞NMPO介导系统的活性均明显降低。结论 新生儿的中性粒细胞功能本身可能存在着发育的不完善。大肠埃希菌刺激时 ,新生儿脐带血NMPO介导系统的活性明显低下 ,可能与新生儿血浆中所含有免疫球蛋白量较低有关 ,这提示免疫?

Objective To evaluate the variety of non myeloperoxidase mediated system activity of neutrophils in newborns during bacterial infection and the effect of cord plasma on the activation of non myeloperoxidase mediated system Methods An infection model with Escherichia coli (E coli) and Staphylococcus aureus (S aureus) and a non infection model with phorbol 12 myristate 13 acetate (PMA) were established to investigate the activation of non myeloperoxidase mediated system in neutrophils According to the intensity of fluorescence, the activation of non myeloperoxidase mediated system of neutrophils was detected by flow cytometry (FCM) The blood cells and plasma were separated from cord blood and adult blood and cross mixed in order to investigate the opsonic activity Results In the non infection model, the activation of non myeloperoxidase mediated system with PMA stimulation in cord blood was lower compared with that in adult blood, the statistical difference was significant ( t =3 378, P <0 01). In the infection model, the activations of non myeloperoxidase mediated system in cord blood were also lower compared with those in adult blood, while the statistical difference could only be found in the model with E coli stimulation ( t =12 150, P <0 001) Furthermore the experiments demonstrated that cord plasma could deeply depress the non myeloperoxidase mediated system activity with E coli stimulation On the contrary, adult plasma could successfully recruit the potential of non myeloperoxidase mediated system activity of neutrophils in newborns Conclusion The function of neonatal neutrophils might not developed very well As a stimulant, E coli failed to induce the non myeloperoxidase mediated system activity in neonates, which might be related to the lower level of immunoglobulins in cord blood This result indicated that immunoglobulins played a more important modulating role in bacterial killing during gram negative bacterial infections