Nybo M, Sørensen O, Leslie R, Wang P
Department of Clinical Biochemistry, Odense University Hospital, Denmark.
Arch Dis Child Fetal Neonatal Ed. 1998 Mar;78(2):F129-32. doi: 10.1136/fn.78.2.f129.
To describe further functional deficiencies of neonatal neutrophils by measuring the expression of C5a receptors.
C5a uptake was measured using flow cytometry with fluorescein isothiocynate labelled recombinant C5a. The response of neutrophils to stimulation with C5a and fMLP was tested by measuring migration and exocytosis of myeloperoxidase and lactoferrin.
C5a mean fluorescence on neutrophils from neonates was significantly lower (22.4 (SD 3.5)) than in adult controls (31.5 (3.1)). Neutrophils from neonates migrated poorly towards both C5a and fMLP compared with those from adult controls. Exocytosis of myeloperoxidase, but not lactoferrin from neonatal neutrophils stimulated with C5a, was significantly lower than in adult controls. fMLP stimulation, on the other hand, resulted in significantly higher exocytosis in neonates.
The lower expression of C5a receptors on neutrophils from neonates could be related to reduced C5a mediated exocytosis of myeloperoxidase.
通过检测C5a受体的表达来进一步描述新生儿中性粒细胞的功能缺陷。
使用异硫氰酸荧光素标记的重组C5a，通过流式细胞术检测C5a摄取。通过测量髓过氧化物酶和乳铁蛋白的迁移和胞吐作用，测试中性粒细胞对C5a和fMLP刺激的反应。
新生儿中性粒细胞上的C5a平均荧光强度（22.4（标准差3.5））显著低于成人对照组（31.5（3.1））。与成人对照组相比，新生儿中性粒细胞对C5a和fMLP的迁移能力较差。C5a刺激新生儿中性粒细胞后，髓过氧化物酶的胞吐作用显著低于成人对照组，但乳铁蛋白的胞吐作用无差异。另一方面，fMLP刺激导致新生儿的胞吐作用显著增强。
新生儿中性粒细胞上C5a受体表达较低可能与C5a介导的髓过氧化物酶胞吐作用降低有关。
