Neonatal sepsis is accompanied by impaired apoptotic depletion of monocytes and macrophages (MΦ), aberrant cytokine production, impaired cell metabolism, and sustained inflammation. Macrophage-colony stimulating factor (M-CSF) triggers the differentiation from monocytes into MΦ (MΦ-0). Interleukin-10 (IL10) and Interferon-gamma (IFNy) further differentiate MΦ subpopulations, the anti-inflammatory MΦ-IL10 and the pro-inflammatory MΦ-IFNy subtype. We previously have shown significant differences between adult (PBMΦ) and cord blood (CBMΦ) in the metabolism of all subtypes. To test the hypothesis whether the competence to differentiate monocytes into MΦ-0 and to polarise into MΦ-IFNy and MΦ-IL10 was diminished in CBMΦ as compared to PBMΦ, we polarised monocytes by cultivation with M-CSF for 72 h, followed by stimulation with IFNy or IL10, for 48 h. After flow cytometry based immunotyping, we tested four functions: Phagocytosis of GFP-E. coli, uptake of erythrocytes, T-cell proliferation, induction of regulatory T-cells as well as phosphorylation analysis of AKT and STAT1/STAT3. Phosphorylation of STAT-1 and STAT-3, obligatory to differentiate into MΦ-IFNγ, MΦ-0 and MΦ-IL10, was found to be aberrant in CBMΦ. Whereas infected MΦ-0 showed identical phagocytic indices and intracellular degradation, TLR4-expression, NFkB up-regulation, IL10-, IL6-, and TNFα production of CBMΦ-0 were reduced. In addition, the capacity to bind aged erythrocytes and the consecutive IL10 production was lower in CBMΦ-IL10. Polarised PBMΦ-IFNy and PBMΦ-IL10 expressed higher levels of co-stimulatory receptors (CD80, CD86), had a higher capacity to stimulate T-cells and induced higher amounts of regulatory T-cells (all p < 0.05 vs. corresponding CBMΦ). Hypoxia-inducible-factor-1α (HIF-1α) was stronger expressed in CBMΦ-IFNy and upregulated in infected CBMΦ-0, whereas heme-oxygenase 1 (HO-1) expression was similar to adult PBMΦ. Neonatal MΦ-0, MΦ-IFNy and MΦ-IL10 polarisation is impaired with respect to phenotype and functions tested which may contribute to sustained inflammation in neonatal sepsis.

中文翻译：

---

极化的新生儿巨噬细胞的功能能力受损。

新生儿败血症伴有单核细胞和巨噬细胞（MΦ）的凋亡减少，细胞因子产生异常，细胞代谢受损和持续炎症。巨噬细胞集落刺激因子（M-CSF）触发单核细胞向MΦ（MΦ-0）的分化。白介素10（IL10）和干扰素-γ（IFNy）进一步区分了MΦ亚群，抗炎MΦ-IL10和促炎MΦ-IFNγ亚型。先前我们已经显示，成人（PBMΦ）和脐带血（CBMΦ）在所有亚型的代谢中均存在显着差异。为了检验关于CBMΦ中单核细胞分化为MΦ-0以及极化为MΦ-IFNγ和MΦ-IL10的能力是否比PBMΦ减弱的假设，我们通过M-CSF培养72 h极化单核细胞，然后进行刺激用IFNy或IL10，持续48小时。基于流式细胞仪的免疫分型后，我们测试了四个功能：GFP-E的吞噬作用。大肠杆菌，红细胞摄取，T细胞增殖，调节性T细胞的诱导以及AKT和STAT1 / STAT3的磷酸化分析。发现在CBMΦ中，STAT-1和STAT-3的磷酸化必须分化为MΦ-IFNγ，MΦ-0和MΦ-IL10。感染的MΦ-0表现出相同的吞噬指数和细胞内降解，而CBMΦ-0的TLR4表达，NFkB上调，IL10-，IL6-和TNFα的产生减少。另外，在CBMΦ-IL10中，结合老化的红细胞的能力和连续的IL10产生较低。极化的PBMΦ-IFNγ和PBMΦ-IL10表达较高水平的共刺激受体（CD80，CD86），具有更高的刺激T细胞的能力并诱导更高数量的调节性T细胞（相对于相应的CBMΦ，所有p <0.05）。缺氧诱导因子-1α（HIF-1α）在CBMΦ-IFNγ中表达较强，在感染的CBMΦ-0中表达上调，而血红素加氧酶1（HO-1）的表达与成年PBMΦ相似。就测试的表型和功能而言，新生儿MΦ-0，MΦ-IFNγ和MΦ-IL10极化均受损，这可能有助于新生儿败血症的持续炎症。