Influence of whole peptidoglycan of bifidobacterium on cytotoxic effectors produced by mouse peritoneal macrophages

INTRODUCTIONBifidobacteria are physiologically beneficial bacteria which are perdominant in human intestine ,and possess the most important functions .They play an important role in maintaining microbial balance of the intestine .Furthermore , their presence is thought to be an important indication of health of the body [1-4].Whole peptidoglycan ( WPG) is the major component in the cell wall of bifidobacterium ,which is also a biological responsemodifier with nontoxic side dffcets.

THE APOPTOSIS OF EXPERIMENTAL COLORECTAL CARCINOMA CELLS INDUCED BY PEPTIDOGLYCAN OF BIFIDOBACTERIUM AND THE EXPRESSION OF APOPTOTIC REGULATING GENES

Objective: To explore the antitumor mechanisms of whole peptidoglycan of bifidobacterium. Methods: The apoptotic cells and the positive expression of bcl-2 and bax oncoprotein were studied nude mice transplantation tumors of colorectal carcinoma by employing in situ end labeling technique and immunohistochemical staining. Results: The apoptotic cell density, the positive rate and the staining intensity of bax oncoprotein of the transplantation tumor of colorectal carcinoma in the whole peptidoglycan injection group were significantly higher when compared with the tumor control group. The positive rate of bcl-2 oncoportein in the whole peptidoglycan injection group was obviously lower than that in the tumor control group (P<0.01). Conclusion: Whole peptidoglycan of Bifidobacterium bifidum could induce cell apoptosis of nude mice transplantation tumors of colorectal carcinoma by down-regulating the expression of the bcl-2 gene and upregulating the expression of the bax gene.

Chemistry and Pharmacological Activity of Peptidoglycan from Lycium Barbaruml

Two homogeneous new peptidoglycans were obtained from Lycium barbarum L. Theywere found to be effective ingredients capable of resining lipid peroxidation. The componentsand linkages of the two homogeneous polysaccharides were studied by means of complete acidhydrolysis, periodate oxidation. Smith degradation enzyme hydrolysis, IR, GC and aminoacid analysis. Homogeneous polysaccharide LBPC2 was found to be a β(1→4)(1→6) peptidoglycanwith MW of 1.2×104, composed of Xyl, Rha. Man in a molar ratio of8.8:2.3;1, LBPC4 was foundto be a a(1→4)(1→6) peptidoglycan with MW of 1.0×104, composed of glucans.

Influence of whole peptidoglycan of Bifidobacterium bifidum on cytokines production by peritoneal macrophages of nude mice

Objective: To explore the functions of whole peptidoglycan (WPG ) of bifidobacterium in regulating immune reactions. Methods: IL- 1 activity produced by peritoneal macrophages was investigated by murine thymocyte proliferating method; The content of IL-6 and IL-12 was detected by ELISA. Results: IL--1 activity and the contents of IL--6 and IL--12 secreted by peritoneal macrophages of nude mice in the WPG injection group were significantly higher than those in the control group (P < 0. 01 ). Conclusion: WPG of bifidobacteria can activate peritoneal macrophages to secret relatively large amount of IL- 1. IL- 6 and IL- 12.

Identification,Phylogeny and Expressional Profiles of Peptidoglycan Recognition Protein(PGRP)Gene Family in Sinonovacula constricta

Peptidoglycan recognition protein(PGRP)plays a vital role in invertebrate innate immunity system as a specific pattern recognition receptor for peptidoglycan.Bivalves possess various PGRP systems for self-defense;however,it has not been characterized in razor clam Sinonovacula constricta.In this study,eight PGRP coding sequences were identified and analyzed from S.constricta genome,which are designated as ScPGRP-S1,ScPGRP-S2,ScPGRP-S3,ScPGRP-S4,ScPGRP-S5,ScPGRP-S6,ScPGRP-S7,ScPGRP-S8.The results of molecular evolutionary analyses showed that all eight ScPGRP genes were highly conserved and exhi-bited a typical PGRP/amidase_2 domain as PGRP genes in other mollusks.Moreover,the presence of signal peptides was predicted in ScPGRP-S2,ScPGRP-S3 and ScPRP-S6,while a transmembrane structure only existed in ScPGRP-S6.Notably,a tertiary struc-ture analysis indicated that no disulfide bond was observed in ScPGRP-S5 and ScPGRP-S7.The mRNA transcripts analysis of ScPGRPs revealed that the high expression patterns of ScPGRP-S1 and ScPGRP-S4 were found in mantle,adductor muscle and foot,while those of ScPGRP-S2,ScPGRP-S3 and ScPGRP-S6 were observed in hepatopancreas.Furthermore,the temporal expression profiles of ScPGRPs in the hepatopancreas were analyzed by qPCR<https://www.sciencedirect.com/topics/immunology-and-microbiology/real-time-polymerase-chain-reaction>after Gram-negative Vibrio parahaemolyticus and Gram-positive Staphylococcus aureus challenges.The mRNA expressions of ScPGRP-S2,ScPGRP-S3 and ScPGRP-S6 could be induced by V.pa-rahaemolyticus and S.aureus.Overall,our findings indicated that ScPGRPs were involved in the immune defense against invaders,which constituted a comprehensive understanding of the potential role of PGRP genes in S.constricta.

The effect of nebivolol on the production of nitric oxide induced by bacterial lipopolysaccharide and peptidoglycan in mice

Nitric oxide (NO) plays a pivotal role in main- taining balance of physiological events in many systems including the autonomic, cardiovas- cular, hematological, and pulmonary systems. Lipopolysaccharide (LPS) and peptidoglycan (PGN), components of the outer cell membranes of Gram-negative bacteria and cell walls of Gram-positive bacteria respectively, are in- criminated in NO-induced septic shock. Ne- bivolol is a third generation β1- adrenoceptor blocker with a vasodilatory property attributed to enhanced availability of nitric oxide and re- duction of cellular oxidative stress through an unknown mechanism. The current study ex- plored the hypothesis that if nebivolol enhances the availability of NO, pretreatment with ne- bivolol may enhance production of NO in re- sponse to subsequent treatment with LPS and PGN, an observation that may have relevance in clinical septic shock. Groups of female BALB/c mice each containing 12 mice (6-8 weeks old) were injected intraperitoneally with LPS (30 μg/mouse), PGN (100 μg/mouse), nebivolol (0.25 μg/g, 0.35 μg/g, 0.7 μg/g), LPS and nebivolol (0.25 μg/g), LPS and nebivolol (0.35 μg/g), LPS and nebivolol (0.7 μg/g), PGN and nebivolol (0.25 μg/g), PGN and nebivolol (0.35μg/g). One group of mice was injected with saline and an- other served as control. Three mice from each group were bled 1, 3, 6 and 9 hours post-injec- tion, the blood was pooled and the nitrite serum levels, reflecting NO concentration, were de- termined using Greiss reagent. The following results were obtained: 1) Treatment with saline did not induce NO production;2) LPS induced NO production to a maximal limit of 545% at 9 hours as compared to treatment with saline;3) PGN did not induce NO production;4) nebivolol at most doses and periods (7 out of 10 deter- minations) increased NO production over a range of 18-110% as compared to treatment with saline;5) Nebivolol enhanced LPS-induced production of NO by 58% at a dose of 0.7 μg/gm at 9 hours. It is concluded that nebivolol in- duces NO production. At low doses nebivolol initially appeared to have a suppressive or no effect on NO production induced by LPS. In- crease in the dose of nebivolol resulted in augmentation of LPS-induced production of NO. PGN, in the dose tested, did not have an effect on NO production.

Distinct immune response induced by peptidoglycan derived from Lactobacillus sp

AIM: To analyze the distinct immune responses induced by Lactobacillus peptidoglycan (PG).METHODS: BALB/c mice were intraperitoneally injected with PG once a day for three consecutive days. Peritoneal macrophage and splenocyte mRNA was extracted and the gene expression profile was studied using high-density oligonucleotide microarrays. Inhibitory effects of Lactobacillus PG on colon tumor tissue were studied in vitro and in vivo.RESULTS: The gene expression profiles revealed that the TLR-NF-κB and Jak-STAT signaling pathways were highly activated. An inflammatory phenotype was induced when peritoneal macrophages were initially exposed to Lactobacillus PG and switched to a more complex phenotype when BALB/c mice were treated with three doses of Lactobacillus PG. A protective physiological inflammatory response was induced after three consecutive days of PG treatment. It was tending toward Th1 dominant immune response. Lactobacillus PG also appeared to induce a significantin vivo anti-colon tumor effect.CONCLUSION: Lactobacillus PG is responsible for certain immune responses induced by Lactobacilli. Anti-tumor effects of Lactobacilli are likely to attribute to the activation of macrophages by PG expressed on the bacterial cell surface.

Effects of different enzymatic hydrolysis methods on the bioactivity of peptidoglycan in Litopenaeus vannamei

The effects of different hydrolysis methods on peptidoglycan(PG) were assessed in terms of their impact on the innate immunity and disease resistance of Pacific white shrimp,Litopenaeus vannamei.PG derived from Bifidobacterium thermophilum was prepared in the laboratory and processed with lysozyme and protease under varying conditions to produce several different PG preparations.A standard shrimp feed was mixed with 0.05% PG preparations to produce a number of experimental diets for shrimp.The composition,concentration,and molecular weight ranges of the soluble PG were analyzed.Serum phenoloxidase and acid phosphatase activity in the shrimp were determined on Days 6-31 of the experiment.The protective activity of the PG preparations was evaluated by exposing shrimp to white spot syndrome virus(WSSV).Data on the composition of the PG preparations indicated that preparations hydrolyzed with lysozyme for 72 h had more low-molecular-weight PG than those treated for 24 h,and hydrolysis by protease enhanced efficiency of hydrolysis compared to lysozyme.SDS-PAGE showed changes in the molecular weight of the soluble PG produced by the different hydrolysis methods.Measurements of serum phenoloxidase and acid phosphatase activity levels in the shrimp indicated that the PG preparations processed with enzymes were superior to the preparation which had not undergone hydrolysis in enhancing the activity of the two serum enzymes.In addition,the preparation containing more low-molecular-weight PG enhanced the resistance of the shrimp to WSSV,whereas no increased resistance was observed for preparations containing less low-molecular-weight PG.These findings suggest that the immunity-enhancing activity of PG is related to its molecular weight and that increasing the quantity of low-molecular-weight PG can fortify the effect of immunity enhancement.

Antiviral function of peptidoglycan recognition protein in Spodoptera exigua(Lepidoptera:Noctuidae)

Peptidoglycan recognition proteins(PGRPs)are a class of molecules that play a critical role in insect immunity.Understanding the function of PGRPs is important to improve the efficiency of microbial insecticides.In this study,we investigated the role of PGRP-LB(a long type PGRP)in insect immunity against viruses using Spodoptera exigua and Spodoptera exigua multiple nucleopolyhedrovirus(SeMNPV)as an insect-virus model.We cloned and identified a PGRP-LB gene from S.exigua;the gene consisted of 7 exons that encoded a polypeptide of 234 amino acids with a signal peptide and a typical amidase domain.Expression analysis revealed that the abundance of SePGRP-LB transcripts in the fat body was greater than in other tissues.Overexpression of SePGRP-LB resulted in a significant decrease of 49%in the rate of SeMNPV-infected cells.In addition,the multiplication of SeMNPV was significantly decreased:a decrease of 79%in the production of occlusion-derived virion(ODV),and a maximum decrease of 50%in the production of budded virion(BV).In contrast,silencing of SePGRP-LB expression by RNA interference resulted in a significant 1.65-fold increase in the rate of SeMNPV-infected cells,a significant 0.54-fold increase in ODV production,a maximum 1.57-fold increase in BV production,and the larval survival dropped to 21%.Our findings show that SePGRP-LB has an antiviral function against SeMNPV,and therefore this gene may provide a target for lepidopteran pest control using virus insecticides.

乳酸菌肽聚糖的提取纯化及其对河豚毒素的毒性消减效果研究

乳酸菌中提取的肽聚糖已被发现对河豚毒素具有消减作用。但肽聚糖提取工艺复杂、效率低下,阻碍了毒素消减研究。该研究以具有A3α,A1γ,A4α三种类型肽聚糖的乳酸菌为原料,通过对磷壁酸去除条件、脂质去除试剂和蛋白质的酶解工艺进行优化获得高纯度肽聚糖,并采用小鼠生物法评价了纯化后的3种肽聚糖对河豚毒素(tetrodotoxin, TTX)的毒性消减效果。溶菌酶及扫描电镜结果显示,采用100 g/L三氯乙酸去除磷壁酸、50 g/L十二烷基硫酸钠溶液去除脂质、胰蛋白酶与链霉蛋白酶联用去除蛋白质后,3种肽聚糖呈现完整的球状形态,表明优化后的提取工艺对肽聚糖的球形结构完整性影响小。酶联免疫吸附法和小鼠生物法结果显示,纯化后的3种肽聚糖可以去除78%以上的TTX含量,并降低87%以上的毒性,消减效果均优于灭活菌株。由此可见,优化后的肽聚糖提取纯化工艺不会破坏肽聚糖消减TTX的主要组分,并能显著提高效率,为肽聚糖的工业化应用和毒素控制研究提供了理论基础。

Comparative analysis of peptidoglycan recognition proteins in endoparasitoid wasp Microplitis mediator

Peptidoglycan recognition proteins （PGRPs） are a family of innate immune receptors that specifically recognize peptidoglycans （PGNs） on the surface of a number of pathogens. Here, we have identified and characterized six PGRPs from endoparasitoid wasp, Microplitis mediator （MmePGRPs）. To understand the roles of PGRPs in parasitoid wasps, we analyzed their evolutionary relationship and orthology, expression profiles during different developmental stages, and transcriptional expression following infection with Gram-positive and -negative bacteria and a fungus. MmePGRP-S1 was significantly induced in response to pathogenic infection. This prompted us to evaluate the effects of RNA interference mediated gene specific knockdown ofMmePGRP-S1. The knockdown of MmePGRP-S1 （iMmePGRP-S1） dramatically affected wasps＇ survival following challenge by Micrococcus luteus, indicating the involvement of this particular PGRP in immune responses against Gram-positive bacteria. This action is likely to be mediated by the Toll pathway, but the mechanism remains to be determined. MmePGRP-S 1 does not play a significant role in anti-fungal immunity as indicated by the survival rate of iMmePGRP-S wasps. This study provides a comprehensive characterization of PGRPs in the economically important hymenopteran species M. mediator.

皱纹盘鲍肽聚糖识别蛋白的表达及免疫功能特性

为研究皱纹盘鲍(Haliotis discus hannai)肽聚糖识别蛋白HdhPGRP-SC2-like的免疫功能特性,利用RACE技术克隆了HdhPGRP-SC2-like基因的全长cDNA序列,采用实时荧光定量PCR(qPCR)分析了HdhPGRP-SC2-like基因的组织分布特征,通过原核表达获得了重组蛋白rHdhPGRP-SC2-like,并对其酰胺酶活性及免疫特性进行了验证。结果表明:HdhPGRP-SC2-like基因的cDNA全长为938 bp,开放阅读框为780 bp,编码260个氨基酸,包含保守的PGRP结构域和Ami_2结构域;HdhPGRP-SC2-like属于短型PGRP,与软体动物近缘物种PGRP具有高度相似性;qPCR分析显示,HdhPGRP-SC2-like mRNA在皱纹盘鲍各组织中均有表达,其中,鳃中表达量最高,外套膜、消化腺中表达量次之,腹足和血细胞中表达量较低;进一步构建原核表达载体pET-28a(+)-HdhPGRP-SC2-like,经诱导表达、分离纯化获得重组蛋白rHdhPGRP-SC2-like,该蛋白具有肽聚糖结合活性,且在Zn2+存在的情况下显示出酰胺酶活性。研究表明,HdhPGRP-SC2-like能够结合细菌肽聚糖成分,在机体抵御入侵细菌等免疫防御中发挥重要作用。

枯草芽孢杆菌肽聚糖对绵羊瘤胃上皮细胞β-防御素-1(SBD-1)表达的影响

为了探究来源于枯草芽孢杆菌细胞壁的肽聚糖对绵羊瘤胃上皮细胞(ORECs)中β-防御素-1(SBD-1)表达的影响,本试验使用30μg/mL肽聚糖刺激ORECs不同时间(2、4、6、8、10和12 h),采用荧光定量PCR(qPCR)和酶联免疫吸附试验(ELISA)方法分别检测SBD-1的mRNA和蛋白表达量,确定最佳刺激时间;再使用不同浓度的肽聚糖(0、10、20、30、40和50μg/mL)刺激ORECs 2 h,采用qPCR和ELISA方法检测SBD-1的mRNA和蛋白表达量,确定最佳刺激浓度。结果显示:(1)使用30μg/mL肽聚糖刺激ORECs不同时间时,SBD-1的mRNA和蛋白表达量随着时间的增加呈先下降后升高的趋势,2 h时表达量最多并极显著高于对照组(P<0.001)。(2)使用不同浓度肽聚糖刺激ORECs 2 h时,SBD-1的mRNA和蛋白表达量随着肽聚糖浓度的升高呈现先升高后降低的趋势,在20μg/mL时表达量最多并极显著高于对照组(P<0.001)。(3)不同时间刺激试验和不同浓度刺激试验均不会对ORECs产生细胞毒性作用。结果表明,来源于枯草芽孢杆菌的肽聚糖能够诱导ORECs表达SBD-1,最佳刺激条件为20μg/mL枯草芽孢杆菌肽聚糖刺激ORECs 2 h。

硒化枯草芽孢杆菌肽聚糖的结构表征及体外抗氧化活性研究

为探究硒化肽聚糖(Se-PG)的结构与抗氧化能力,以枯草芽孢杆菌(Bacillus subtilis)胞壁肽聚糖(PG)和亚硒酸钠为原料,利用HNO_(3)-Na_(2)SeO_(3)法对PG进行硒化修饰,制备Se-PG复合物。通过紫外光谱、傅里叶红外光谱及核磁共振研究Se-PG结构特征,从对DPPH、ABTS、·OH自由基的清除能力评价其体外抗氧化活性。结果表明:Se-PG的硒含量为369.32μg/g,傅里叶红外光谱在890 cm_(-1)有吸收峰,表明形成亚硒酸酯键;Se-PG对DPPH、ABTS和·OH自由基清除率具有质量浓度依赖效应,当质量浓度达到5 mg/mL时,自由基清除率分别为39.51%±0.26%、39.47%±0.98%、48.38%±1.42%,显著高于亚硒酸钠和PG(P<0.05)。结构表征表明B.subtilis PG可进行硒化修饰且不改变PG的基本结构。Se-PG具有优越的体外自由基清除能力和抗氧化活性,可作为功能性抗氧化剂进行开发。

高表达GFP-PBP1b融合蛋白的猪链球菌菌株的构建及PBP1b蛋白细胞定位的研究

为鉴定猪链球菌(Streptococcus suis)A型青霉素结合蛋白PBP1b在S.suis中的细胞定位,本研究经PCR扩增S.suis pbp1b基因融合位点上下游序列UP和DN、强启动子Peno基因片段及绿色荧光蛋白(GFP)gfp基因片段,再通过重叠延伸PCR扩增构建融合片段UP-Peno-GFP-DN。利用同源重组的方法将UP-Peno-GFP-DN转化含反向筛选标记的PSS-pbp1b中间菌株,经含7%蔗糖的TSAS平板筛选,挑单菌落进行PCR及测序鉴定。PCR及测序鉴定结果显示,获得的重组菌株中Peno-gfp片段替换了PSS-pbp1b中的PSS片段,表明融合强启动子Peno、GFP及PBP1b(GFP-PBP1b)的重组菌株P-GFP-pbp1b正确构建。以S.suis 05ZYH33株和本实验室前期构建的GFP-pbp1b为对照,培养P-GFP-pbp1b菌株并测定OD600nm值,绘制各菌株的生长曲线;采用western blot检测P-GFP-pbp1b菌株中GFP-PBP1b融合蛋白的表达水平,并与GFP-pbp1b菌株进行比较;利用Alexa Fluor 633-WGA染色,经超高分辨显微镜观察GFP-pbp1b和P-GFP-pbp1b菌株形态及GFP-PBP1b融合蛋白在S.suis细胞中的定位。生长曲线结果显示,S.suis融合菌株GFP-pbp1b和P-GFP-pbp1b均正常生长;western blot结果显示,GFP-pbp1b和P-GFP-pbp1b菌株均能够表达GFP-PBP1b融合蛋白,但强启动子驱动的P-GFP-pbp1b菌株中GFP-PBP1b蛋白表达量较GFP-pbp1b菌株提高了6倍(P<0.01);超高分辨显微镜观察结果显示,GFP-pbp1b和P-GFP-pbp1b菌株形态均正常,GFP-pbp1b菌株中GFP荧光较弱,难以定位GFP-PBP1b,而P-GFP-pbp1b菌株中GFP荧光较强,能够明显观察到融合蛋白GFP-PBP1b定位在S.suis的细胞横隔和两极。本研究通过构建高表达GFP-PBP1b融合蛋白的P-GFP-pbp1b菌株首次观察到PBP1b在S.suis中的细胞定位,为进一步研究PBP1b在S.suis细胞壁肽聚糖合成中的作用奠定了基础。

亚洲玉米螟肽聚糖识别蛋白OfPGRP-SA的表达与功能分析

目的:明确肽聚糖识别蛋白PGRP在亚洲玉米螟先天免疫中的功能。方法:构建质粒表达载体,进行重组蛋白表达、纯化及Western blot鉴定,对获得的OfPGRP-SA重组蛋白进行抗菌活性、细菌凝集、酰胺酶活性、酚氧化酶反应和黑化反应等体外试验。结果:通过SDS-PAGE和Western blot鉴定,OfPGRP-SA蛋白纯化后条带单一,与预期大小一致。对重组蛋白体外活性分析表明,OfPGRP-SA对革兰氏阳性菌有较强的诱导作用,说明OfPGRP-SA可能参与Toll途径的激活。结论:进一步明确OfPGRP-SA在亚洲玉米螟先天免疫应答中的作用,有助于更好地利用病原微生物对亚洲玉米螟进行生物防治。

ADA、PGLYRP2及PCT在耐多药肺结核诊断中的潜在价值

目的探讨腺苷脱氨酶(ADA)、肽聚糖识别蛋白2(PGLYRP2)及降钙素原(PCT)在耐多药肺结核诊断中的潜在价值,以期为临床治疗提供参考。方法选取2019年5月—2022年1月在河南省禹州市疾病预防控制中心门诊就诊的110例耐多药肺结核患者作为耐药组,同期选择在本院门诊就诊的首次发现痰检结核杆菌阳性且无耐药史的肺结核患者110例作为敏感组。分析ADA、PGLYRP2、PCT在耐多药肺结核诊断中的潜在价值。结果耐药组患者PGLYRP2、PCT水平高于敏感组,而ADA水平低于敏感组,差异均有统计学意义(P<0.05)。ROC显示:ADA、PGLYRP2、PCT诊断耐多药肺结核的AUC分别为0.773(95%CI:0.700~0.845)、0.789(95%CI:0.707~0.871)、0.804(95%CI:0.669~0.939)。ADA的Cut-off=16.92 U/L、PGLYRP2的Cut-off=544.62 pg/mL、PCT的Cut-off=0.58 ng/mL,在该阈值下,诊断的灵敏度和特异度最高。结论PGLYRP2、PCT在耐多药肺结核患者体内呈高表达状况,ADA呈低表达状况,ADA、PGLYRP2、PCT水平与耐多药肺结核的发生存在相关性,可用于诊断耐多药肺结核。

A3α肽聚糖对牙鲆不同组织中超氧化物歧化酶及磷酸酶活性的影响

研究了口服不同剂量的A3α肽聚糖 (A3α -PG)对牙鲆 (Paralichthysolivaceus)体表粘液和组织中超氧化物歧化酶(Superoxidedismutase,SOD)、酸性磷酸酶 (Acidphosphatase,ACP)及碱性磷酸酶 (Alkalinephosphatase,AKP)活力的影响。饲料中A3α -PG添加量分别为 0 (对照 ) ,0 .0 5 % ,0 .10 % ,0 .2 0 % ,0 .4 0 % ,0 .80 %和 1.6 0 % (质量比 ) ,饲喂天数为 4 0d。结果表明 ,饲料中未添加A3α -PG时 ,牙鲆体表粘液、肾脏、肝脏和肌肉中SOD、ACP及AKP活性各异 ,其中SOD活性从高到低依次为粘液、肝脏、肌肉、肾脏 ;ACP活性大小依次为肝脏、肾脏、肌肉、粘液 ;AKP活性大小依次为肾脏、肝脏、肌肉 ,粘液中则检测不到AKP。饲料中添加A3α -PG后 ,实验组与对照组相比 ,各组织中SOD活性变化不大 ,未见显著性差异 (P>0 .0 5 )。ACP活性 ,肌肉与粘液中未见显著提高 ;而在肝脏中 0 .0 5 %和 0 .4 0 % (质量比 )剂量组能显著提高其ACP活性 ,与对照差异显著 (P <0 .0 5 ) ;在肾脏中 ,0 .2 0 % (质量比 )剂量组使其ACP活力得以显著提高 (P <0 .0 5 )。AKP活性呈现不同组织变化趋势各异 ,肌肉中没有明显提高 ,而在肾脏与肝脏中 ,除两个低剂量组 (0 .0 5 %和 0 .10 % ) (质量比 )未能使AKP活力得以显著提高外 ,其他剂量组?

乳酸杆菌通过定植和提供免疫信号调节宿主免疫反应

提取了Lactobacillussp.的肽聚糖,用AffymetrixMOE430A基因芯片研究了肽聚糖对机体免疫细胞基因表达的影响。结果发现,乳酸杆菌肽聚糖可以刺激免疫细胞Th1型免疫反应相关基因的表达,可能激活TLR-NF-κB相关信号通路,同时,不同剂量的肽聚糖可能通过调节Tollip的表达,影响TLR-NF-κB信号通路的激活,从而调节细胞因子的表达。

双歧杆菌的全肽聚糖对裸鼠腹腔巨噬细胞产生IL-6、IL-12及一氧化氮的影响

目的 :探讨分叉双歧杆菌 (B bifidum)的全肽聚糖对巨噬细胞功能的调节作用。方法 :首先用全肽聚糖注射于裸鼠腹腔 ,以ELISA法测定裸鼠腹腔巨噬细胞产生的IL - 6和IL - 12含量 ,同时用Griess试剂检测一氧化氮 (NO)的水平。结果 :全肽聚糖注射组裸鼠腹腔巨噬细胞产生的IL - 6、IL - 12及NO含量分别为732 5 4± 190 30 (pg/mL)、816 37± 96 40 (pg/mL)和 48 90± 6 5 1(μmol/L) ;对照组分别为 30 3 78± 171 75 (pg/mL)、5 10 2 7± 12 3 46 (pg/mL)以及 30 6 7± 12 83(μmol/L) ,三者比较均具有显著差异 (P <0 0 1)。 结论 :分叉双歧杆菌的全肽聚糖能激活巨噬细胞 ,使之分泌多量的IL - 6、IL - 12及NO ,这些细胞毒性效应分子介导了全肽聚糖的多种重要生理功能。