Polymorphonuclear leukocyte dysfunction syndrome in patients with increasing sepsis severity
Polymorphonuclear leukocyte dysfunction syndrome in patients with increasing sepsis severity
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DOI：
10.1097/01.shk.0000223131.64512.7a
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发表时间：
2006-09-01
期刊：
影响因子：
3.1
通讯作者：
Thiel, Manfred
中科院分区：
文献类型：
--
作者：
Kaufmann, Ines;Hoelzl, Alwin;Thiel, Manfred
氧自由基的产生是粒细胞的杀微生物和组织毒性效应功能所必需的。由于多形核白细胞（PMNs）的矛盾作用在脓毒症过程中可能变得明显，我们研究了不同的颗粒和可溶性刺激的性质，在脓毒症严重程度增加的患者的PMNs的过氧化氢（H2 O2）的生产水平。脓毒症（n = 15）、严重脓毒症（n = 12）或脓毒性休克（n = 33）患者前瞻性入组研究。年龄和性别相当的健康志愿者作为对照组（n = 50）。未调理和调理酵母多糖颗粒被用来评估粘附，吞噬作用，和相关的H2 O2的生产。酵母多糖颗粒富含β-葡聚糖和凝集素结构，已知其通过两种主要的非toll样受体病原体识别受体触发H2 O2产生，包括补体受体3型α链（CD 11b）中的凝集素结合位点和最近鉴定的非经典C型凝集素dectin-1。为了测定可溶性刺激物激活细胞后H2 O2的产生，PMN被趋化性三肽（N-甲酰基-甲硫氨酰基-亮氨酰基-苯丙氨酸[fMLP]）单独激活，或在用肿瘤坏死因子a预孵育引发细胞后激活。为了深入了解fMLP受体经典的细胞内信号转导途径的变化，还将PMN与钙离子载体A23187和佛波酯佛波肉豆蔻酸酯乙酸酯一起孵育，绕过受体依赖的信号转导，分别直接激活钙/钙调蛋白激酶和蛋白激酶C依赖的途径。与健康志愿者相比，脓毒症患者的PMN产生H2 O2的水平根据激活信号的性质而变化：减少（酵母聚糖），不变（佛波醇肉豆蔻酸酯乙酸酯，调理酵母聚糖）和增强（自发，fMLP，fMLP +肿瘤坏死因子α，A23187），脓毒性休克患者的变化最明显。具体而言，酵母聚糖的吞噬作用和相关的H2 O2生产显着下降，而自发和刺激H2 O2生产引起的可溶性刺激强烈增加。因此，这些研究结果表明，在脓毒症严重程度增加的患者中，PMN功能障碍综合征的发展。此外，尽管吞噬作用和相关的H2 O2产生受到越来越多的抑制，但酵母聚糖颗粒与PMN表面的结合保持不变，因此观察到的效应可能分别反映了CD 11b和/或β-葡聚糖受体dectin-1的凝集素结合位点的信号传导缺陷。
Production of oxygen radicals is required for both microbicidal and tissue-toxic effector functions of granulocytes. Inasmuch as an ambivalent role of polymorphonuclear leukocytes (PMNs) may become apparent during sepsis, we studied levels of hydrogen peroxide (H2O2) production by PMNs depending upon the nature of different particulate and soluble stimuli in patients with increasing sepsis severity. Patients with sepsis (n = 15), severe sepsis (n = 12), or septic shock (n = 33) were prospectively enrolled in the study. Healthy volunteers of comparable age and sex served as controls (n = 50). Unopsonized and opsonized zymosan particles were used to assess adhesion, phagocytosis, and the associated H2O2 production. Zymosan particles are rich in beta-glucans and lectin structures that are known to trigger H2O2 production via two major non-toll-like receptor pathogen recognition receptors, comprising the lectin-binding site in the alpha-chain (CD11b) of the complement receptor type 3 and the more recently identified nonclassical C-type lectin, dectin-1. To determine H2O2 production upon cell activation by soluble stimuli, PMNs were activated by the chemotactic tripeptide (N-formyl-methionyl-leucyl-phenylalanine [fMLP]) alone or after priming of cells by preincubation with tumor necrosis factor a. To get insight into the changes of fMLP receptor classical intracellular signaling pathways, PMNs were also incubated with the calcium ionophore A23187 and the phorbol ester phorbol myristate acetate, bypassing receptor-dependent signal transduction to directly activate calcium/calmodulin kinase- and protein kinase C-dependent pathways, respectively. As compared with healthy volunteers, levels of H2O2 production by PMNs from septic patients varied depending upon the nature of the activating signal: reduced (zymosan), unchanged (phorbol myristate acetate, opsonized zymosan), and enhanced (spontaneous, fMLP, fMLP + tumor necrosis factor alpha, A23187), with the changes most pronounced in patients with septic shock. Specifically, phagocytosis of zymosan and the associated H2O2 production were significantly decreased whereas spontaneous and stimulated H2O2 production elicited by soluble stimuli strongly increased. Thus, these findings suggest the development of a PMN dysfunction syndrome in patients with increasing sepsis severity. Moreover, as binding of zymosan particles to the PMNs' surface remained unchanged despite increasingly suppressed phagocytosis and associated H2O2 Production, observed effects are likely to reflect defects in signaling by the lectin-binding site of CD11b and/or the beta-glucan receptor dectin-1, respectively.