海洋细菌生物膜用于生物修复陆地生态系统中土壤多环芳烃污染

Polycyclic aromatic hydrocarbons(PAHs) in soil retain for a quite long period due to their hydrophobicity and aggregation properties. Biofilm-forming marine bacterial consortium(named as NCPR), composed of Stenotrophomonas acidaminiphila NCW702,Alcaligenes faecalis NCW402, Pseudomonas mendocina NR802, Pseudomonas aeruginosa N6P6, and Pseudomonas pseudoalcaligenes NP103, was used for the bioremediation of PAHs in a soil microcosm. Phenanthrene and pyrene were used as reference PAHs. Parameters that can affect PAH degradation, such as chemotaxis, solubility of PAHs in extracellular polymeric substances(EPS), and catechol2,3-dioxygenase(C23O) activity, were evaluated. P. aeruginosa N6P6 and P. pseudoalcaligenes NP103 showed chemotactic movement towards both the reference PAHs. The solubility of both the PAHs was increased with an increase in EPS concentration(extracted from all the 5 selected isolates). Significantly(P 0.001) high phenanthrene(70.29%) and pyrene(55.54%) degradation was observed in the bioaugmented soil microcosm. The C23O enzyme activity was significantly(P 0.05) higher in the bioaugmented soil microcosm with phenanthrene added at 173.26 ± 2.06 nmol min~(-1) mg~(-1) protein than with pyrene added at 61.80 ± 2.20 nmol min~(-1) mg~(-1) protein. The C23O activity and gas chromatography-mass spectrometer analyses indicated catechol pathway of phenanthrene metabolism. However, the metabolites obtained from the soil microcosm added with pyrene revealed both the catechol and phthalate pathways for pyrene degradation.     

Oxidized α1-antitrypsin induces IL-8 and MCP-1 production in HBE cells

AIM:To investigate the effect of oxidized α1-antitrypsin (Ox-AT) on interleukin 8 (IL-8) and monocyte chemotactic protein 1(MCP-1) production in cultured human bronchial epithelial (HBE) cells. METHODS:Plasma native α1-antitrypsin (N-AT) was purified from human plasma by 50% and 75% ammonium sulfate fractionation followed by glutathione and anion exchange chromatography. Ox-AT was prepared by incubating N-AT (0.5 g/L) with N-chlorosuccinimide in a 25-fold molar excess to N-AT in PBS at room temperature for 30 min. HBE cells were cultured in the presence of Ox-AT (0.5 g/L) for 4 h, 10 h and 24 h, and the levels of IL-8 and MCP-1 in the supernatant were assayed using respective DuoSet kits. The effect of NF-κB inhibitor Bay11-7082 on the inflammatory cytokine release induced by Ox-AT was also evaluated. RESULTS:Ox-AT concentration-dependently and time-dependently increased the production of IL-8 and MCP-1 in HBE cells. The concentrations of IL-8 and MCP-1 in HBE cells induced by 0.5 g/L Ox-AT at 4 h, 10 h and 24 h were significantly higher than those in blank control and N-AT groups. Ox-AT increased the activity of NF-κB in a dose-dependent manner. The proinflammatory effect of by Ox-AT was inhibited by NF-κB inhibitor Bay11-7082. CONCLUSION: Ox-AT is a strong proinflammatory factor for HBE cells. The mechanism is related to NF-κB signaling pathway activation.     

Rapid activation of Mac-1(CD11b/CD18) molecules on macrophages by a new chemotactic factor 'Gasserokine' produced by Lactobacillus gasseri JCM1131T

The chemoattractant activity of a new chemotactic factor, 'Gasserokine' produced by Lactobacillus gasseri JCM1131^T, has been proposed as a novel immunological function of probiotic lactic acid bacteria. The focus of the present study was to understand the mechanism of the chemotaxis induced by Gasserokine, using activation of an adhesion molecule, Mac-1 (CD11b/CD18) on macrophages. The macrophage chemotaxis to Gasserokine was abolished by preincubation of macrophages with the anti-Mac-1 mAb. Gasserokine induced rapid serine phosphorylation of CD18 molecules within 1 min of stimulation, but the effect was short-lived. Substantial tyrosine phosphorylation was observed in CD18-associated protein of macrophages stimulated by Gasserokine. The tyrosine phosphorylation was confirmed in macrophages stimulated with Gasserokine and also serine/threonine phosphorylation was detected on CD18 molecules by laser microscopy using a double immunostaining method. These results suggest that selective activation of intracellular signaling cascades, such as the mitogen-activated protein kinase pathway, are related to the macrophage chemotaxis induced by Gasserokine.     

猪圆环病毒2型感染猪皮肤源树突状细胞炎性反应能力的变化

用PCV2 B1株经鼻腔接种40日龄SPF仔猪,于接种后3、7、14 d宰杀,收集皮肤源树突状细胞(DC).利用实时荧光定量PCR技术对感染仔猪皮肤源DC的IL-10、TNF-α、IFN-α、IL-8、趋化因子受体1(CCR1)、CCR5在mRNA转录水平的变化进行定量分析.结果表明,IFN-α在接种后3 d(3DPI)显著下调(P＜0.05),TNF-α、IL-10在7DPI时显著上调(P＜0.05);趋化因子IL-8在3、7、14 DPI时均下调,差异接近显著;MCP-1在感染后3、14DPI下调,7DPI均上调,但不显著;MIP-1β在3、7DPI明显上调,14DPI恢复正常;趋化因子受体CCR1、CCR5在3、7和14DPI均上调,且7DPI显著上调(P＜0.05).以上结果表明PCV2在感染早期可抑制DC炎性反应的能力,免疫应答失调,影响了动物机体的细胞和体液免疫功能的发挥.     

蛴螬提取物对脉络膜新生血管中趋化因子受体3及其配体嗜酸性粒细胞趋化因子表达的影响

目的 观察蛴螬提取物口服、滴眼两种给药途径对实验眼脉络膜新生血管（Choroidal neovascularization,CNV）组织的趋化因子受体3（chemokine receptor 3,CCR3）及其配体嗜酸性粒细胞趋化因子（eosinophil activated chemotactic factor,Eotaxin）表达的影响。方法 选用8周龄雄性BN大鼠32只,随机数字表法平均分成空白组、模型组、口服组、滴眼组,予以不同干预措施。采用YAG激光建立CNV大鼠模型,于造模后7、28 d行荧光素眼底血管造影（fluorescein fundus angiography,FFA）检查,造模后28 d行免疫组化CCR3及其配体Eotaxin染色及其结果观察分析。结果 FFA检查显示：造模后7 d除空白组外,各组均造模成功;造模后28 d口服组与滴眼液荧光渗漏减少。CCR3及Eotaxin免疫组化结果示：口服组与滴眼组CCR3及Eotaxin含量较模型组减少,差异有统计学意义（P<0.05）;口服组与滴眼组相比,差异无统计学意义（P>0.05）。结论 蛴螬提取物两种给药途径均可抑制实验性CNV模型中CCR3及其配体Eotaxin的表达,从而抑制实验性CNV的形成。     

Role of caveolin-1 on down-regulation of LPS-induced monocyte chemotactic protein 1 by 17β-estradiol in vascular smooth muscle cells

AIM: To elucidate the effect of caveolin-1 on the down-regulation of LPS-induced monocyte chemotactic protein 1 (MCP-1) by 17β-estradiol (E₂) in vascular smooth muscle cells (VSMCs).METHODS: The primary-cultured VSMCs were exposed to E₂ at concentrations of 10^-9-10^-6 mol/L. LPS-induced MCP-1 production was assayed by ELISA. The protein expression of caveolin-1 was determined by Western blotting and was silenced by β-methyl cyclodextrin(β-MCD) or caveolin-1 specific siRNA. RESULTS: LPS significantly enhanced MCP-1 production. E₂ at concentrations of 10^-9-10^-6 mol/L inhibited LPS-induced MCP-1 production. The use of caveolin-1 inhibitor β-MCD or silencing the protein expression of caveolin-1 by specific siRNA largely impaired LPS-enhanced MCP-1 production, while E₂ markedly inhibited caveolin-1 expression. CONCLUSION: Inhibition of LPS-induced MCP-1 production by E₂ is related to the suppression of caveolin-1.     

鼠李糖乳杆菌对巨噬细胞先天性免疫应答的调节作用

【目的】通过测定先天性免疫效应因子分泌水平的变化,研究鼠李糖乳杆菌（Lactobacillus rhamnosus）体外对巨噬细胞先天性免疫应答调节的影响。【方法】将培养好的鼠巨噬细胞系RAW264.7细胞分为4组,分别用PBS（CT组,对照组）、Escherichia coli K88（EC组）和Lactobacillus rhamnosus（LR组）处理12 h,以及先用Lactobacillus rhamnosus预处理1 h,再用Escherichia coli K88处理12 h（LR-EC组）。试验结束时,收集各组的细胞培养液,用ELISA检测TNF-α、IFN-γ、IL-1β、IL-6、IL-12、IL-8、IL-10,以及PGE2和 的含量。【结果】结果表明,CT组（对照组）可产生TNF-α、IFN-γ、IL-8和IL-10,几乎不产生IL-1β、IL-6和IL-12。与对照组相比,EC组TNF-α、IFN-γ、IL-8、IL-10及PGE2和 含量均极显著提高（P＜0.01）,且可大量产生IL-1β、IL-6和IL-12;LR组TNF-α、IFN-γ、IL-10及PGE2和 也极显著提高（P＜0.01）,IL-8显著增加（P＜0.05）,同样不产生IL-1β和IL-6,但可产生微量的IL-12（P＜0.01）;LR-EC组所有的促炎细胞因子（TNF-α、IFN-γ、IL-1β、IL-6、IL-12）、趋化因子IL-8和PGE2均极显著高于EC组（P＜0.01）,但IL-10和 含量都显著低于EC组（P＜0.01）。【结论】在体外试验条件下,鼠李糖乳杆菌作为益生菌对生理状态下巨噬细胞先天性免疫应答的刺激作用远低于病原菌,不会产生炎症反应,但可极大增强受感染巨噬细胞的促炎免疫应答水平,且可能具有避免过度炎症反应的作用。     

河流弧菌对牙鲆表皮粘液的趋化作用

病原菌对粘液的趋化作用在其对粘液层定植过程中起着重要作用，趋化作用是病原菌的毒力机制之一。为了解病原性河流弧菌对牙鲆表皮粘液的趋化作用，本文采用改良的毛细管法研究了细菌浓度、孵育时间、孵育温度、pH值、NaCl浓度、碳水化合物等对河流弧菌趋化作用的影响。试验结果表明：在较低浓度下，河流弧菌对牙鲆表皮粘液的趋化量随着菌浓度的升高而增大；在室温下河流弧菌的趋化量随着孵育时间的延长而增加，60 min趋于饱和；孵育温度在4～15 ℃范围内趋化作用随温度升高而增强，15 ℃时达最大值；pH值为8时细菌的趋化性最强；NaCl浓度超过0.8 %,河流弧菌的趋化性随着浓度升高而显著减弱（P<0.05）；7种碳水化合物中甘露醇、乳糖、甘露糖能够极显著地促进河流弧菌对牙鲆表皮粘液的趋化作用（P<0.01）。以上结果说明：牙鲆表皮粘液对河流弧菌有较强的趋化作用，该趋化作用受环境因子的影响较大；本文所揭示的河流弧菌趋化特性将对养殖牙鲆疾病防治提供有价值的参考。