TUMOR-NECROSIS-FACTOR INDUCTION BY AN AQUEOUS PHENOL-EXTRACTED LIPOPOLYSACCHARIDE COMPLEX FROM BACTEROIDES SPECIES
TUMOR-NECROSIS-FACTOR INDUCTION BY AN AQUEOUS PHENOL-EXTRACTED LIPOPOLYSACCHARIDE COMPLEX FROM BACTEROIDES SPECIES
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DOI：
10.1128/iai.63.3.840-846.1995
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发表时间：
1995-03-01
影响因子：
3.1
通讯作者：
POXTON, IR
中科院分区：
文献类型：
--
作者：
DELAHOOKE, DM;BARCLAY, GR;POXTON, IR
脂多糖（LPS）刺激巨噬细胞和单核细胞导致肿瘤坏死因子（TNF）的分泌，TNF是一种细胞因子，被认为在随后的宿主反应中起关键作用。它的诱导被认为是通过LPS复合物和LPS结合蛋白与CD14的结合而促进的。拟杆菌属的脂多糖被认为是一种弱内毒素；然而，在最近的一项研究中，我们已经表明，从拟杆菌属中提取的LPS的生物活性和化学成分取决于提取方法。本研究确定了水苯酚提取的脂多糖（生产高内毒活性脂多糖的方法）从四种拟杆菌中诱导TNF的能力。研究了人单核白细胞（MNL）、THP-1细胞（有或没有维生素D-3增强CD14）和C3H/HeJ （LPS无应答）和C3H/HeN （LPS应答）小鼠的腹腔巨噬细胞的诱导作用。以大肠杆菌O18K（-）脂多糖为典型的非均匀分子质量光滑脂多糖作为对照。在MNL、THP-I细胞（CD14增强）和C3H/HeN小鼠的腹膜巨噬细胞中，E. call LPS对TNF生成的刺激作用是拟杆菌LPS的两到四倍。在THP-1细胞中（未增强CD14），大肠杆菌和拟杆菌脂多糖之间TNF的产生无显著差异。在C3H/HeJ小鼠腹腔巨噬细胞中，大肠杆菌LPS对TNF的产生没有刺激作用，但拟杆菌LPS对C3H/HeJ小鼠腹腔巨噬细胞和C3H/HeN小鼠腹腔巨噬细胞TNF的产生无显著差异。在所有细胞群中，所有lps刺激约4小时后TNF的产生达到峰值。然而，仅在大肠杆菌LPS刺激后，MNL和THP-I细胞（CD14增强）中出现了TNF生成的其他峰值。在拟杆菌脂多糖与大肠杆菌脂多糖一起但超过大肠杆菌脂多糖的刺激试验中，发现MNL和THP-1细胞（有或没有CD14增强）产生的TNF与单独拟杆菌脂多糖而不是单独大肠杆菌脂多糖相当。抗cd14单克隆抗体不抑制拟杆菌脂多糖刺激的TNF产生。然而，大肠杆菌lps刺激的TNF释放被抗CD14单克隆抗体抑制，在MNL和THP-1细胞中最明显（CD14增强）。我们得出结论，当过量存在时，拟杆菌脂多糖可以掩盖大肠杆菌脂多糖的作用，只能产生一个TNF生成峰，并通过不依赖CD14的途径激活单个核细胞。
The stimulation of macrophages and monocytes by lipopolysaccharide (LPS) results in the secretion of tumor necrosis factor (TNF), a cytokine which is thought to play a pivotal role in subsequent host responses. Its induction is thought to be facilitated by the binding of complexes of LPS and LPS-binding protein to CD14. The LPS of Bacteroides species was considered a weak endotoxin; however, in a recent study we have shown that the biological activity and chemical composition of the LPS from Bacteroides species are dependent on the extraction method. The present study determines the capacity of LPS extracted by aqueous phenol (the method for producing an LPS of high endotoxic activity) from four species of Bacteroides to induce TNF. Induction was investigated from human mononuclear leukocytes (MNL), THP-1 cells (with and without enhancement by vitamin D-3 for CD14), and peritoneal macrophages from C3H/HeJ (LPS nonresponder) and C3H/HeN (LPS responder) mice. Escherichia coli O18K(-) LPS, a typical smooth LPS of heterogeneous molecular mass, was used as a control throughout. The stimulation of TNF production by E. call LPS was between two- and fourfold more than that by Bacteroides LPS in MNL, in THP-I cells (with enhancement for CD14), and in peritoneal macrophages from C3H/HeN mice. In THP-1 cells (without enhancement for CD14), there was no significant difference in TNF production between E. coli and Bacteroides LPSs. In peritoneal macrophages from C3H/HeJ mice, E. coli LPS stimulated no TNF production, but there was no significant difference in TNF production from peritoneal macrophages from C3H/HeJ and C3H/HeN mice by Bacteroides LPS. In all cell populations, there was a peak of TNF production after approximately 4 h of stimulation with all LPSs tested. However, other peaks of TNF production were seen in MNL and THP-I cells (with enhancement for CD14) after stimulation with E. coli LPS only. In stimulation assays in which Bacteroides LPS was together with but in excess of E. coli LPS, it was found that TNF production from MNL and THP-1 cells (with and without enhancement for CD14) was comparable to that of Bacteroides LPS alone and not E. coli LPS alone. An anti-CD14 monoclonal antibody did not inhibit Bacteroides LPS-stimulated TNF production. However, E. coli LPS-stimulated TNF release was inhibited by an anti-CD14 monoclonal antibody, most noticeably in MNL and THP-1 cells (with enhancement for CD14). We conclude that Bacteroides LPS can mask the effects of E. coli LPS when present in excess, can produce only one peak of TNF production, and activates mononuclear cells by a pathway not dependent on CD14.