应用体内外实验筛选可降低牛乳β-乳球蛋白过敏的乳杆菌

【目的】通过体内外实验评估5种乳杆菌缓解牛乳β-乳球蛋白(BLG)过敏的作用,为今后筛选具有抗过敏活性的乳杆菌提供参考。【方法】首先体外分析5种活的/热致死的乳杆菌促进小鼠原代淋巴细胞分泌细胞因子(CK)IFN-γ和IL-4的水平,随后应用小鼠BLG过敏模型评估这5种乳杆菌抑制过敏的能力。将实验动物随机分为空白组、BLG致敏组和5种活的/热致死乳杆菌组。采用ELISA法检测各组小鼠淋巴细胞分泌Thl/Th2型CK的水平,并测定小鼠血清中总IgE和BLG特异性IgE的含量。【结果】在体外可促进淋巴细胞分泌IFN-γ、抑制IL-4,使其IFN-γ/IL-4比值(代表Thl/Th2细胞平衡)显著高于正常对照组(P<0.05)的乳杆菌,在体内实验中也能有效提高致敏小鼠淋巴细胞的IFN-γ/IL-4分泌率,并显著降低致敏小鼠血清中总IgE和BLG特异性IgE的水平(P<0.05)。相反,在体外的IFN-γ/IL-4比值较低的乳杆菌,不能缓解特异性IgE抗体介导的食物过敏反应。【结论】基于乳杆菌体外刺激小鼠原代淋巴细胞分泌Th1/Th2型CK的结果,可以预测菌株在体内具有可通过纠正Th2占优势的Th1/Th2细胞失衡,下调抗体分泌量,缓解小鼠BLG过敏症状的能力。     

乳杆菌肽聚糖对β-乳球蛋白致敏小鼠脾细胞Th1/Th2及Treg/Th17失衡的体外影响

【目的】观察嗜酸乳杆菌完整肽聚糖(Whole peptidoglycan,WPG)对致敏脾淋巴细胞Th1/Th2及Treg/Th17平衡的体外调节作用。【方法】通过腹腔注射β-乳球蛋白(β-Lg)建立BALB/c小鼠牛乳过敏模型。造模成功后,分离致敏小鼠的脾淋巴细胞并分别与不同剂量的WPG共同孵育,酶联免疫法检测细胞上清液中抗体(总IgE和特异性IgE),Th1/Th2及Treg/Th17相关细胞因子(IFN-γ,IL-4,TGF-β,IL-17)水平,流式细胞术检测脾淋巴细胞中CD3+、CD4+和CD8+的百分含量,荧光定量PCR法检测过敏小鼠脾细胞中Th1/Th2及Treg/Th17相关转录因子T-bet、GATA-3、Foxp3和RORγt mRNA的表达量。【结果】WPG体外刺激致敏脾细胞后可显著抑制IgE的产生,上调CD3+、CD4+细胞数及CD4+/CD8+比值,下调Th2型因子(IL-4,GATA-3mRNA)和Th17型因子(IL-17,RORγt mRNA)的表达,且与过敏组相比,中、高剂量WPG的作用效果显著(P0.05);另外,WPG体外作用还上调了Th1型因子(IFN-γ,T-bet mRNA)及Treg型因子(TGF-β,Foxp3 mRNA)的表达,且具有剂量依赖性。【结论】嗜酸乳杆菌WPG体外刺激可有效纠正致敏脾淋巴细胞的Th1/Th2及Treg/Th17失衡。     

Continuous Orally Administered Coffee Enhanced the Antigen-Specific Th1 Response and Reduced Allergic Development in a TCR-Transgenic Mice Model

Coffee is a globally consumed beverage. Although recent studies have suggested that coffee reduced the risk of lifestyle-related diseases, there are few studies regarding allergic response.

This study investigates the effects of orally administered coffee (91 ml/kg/d) on allergic responses using a T cell receptor (TCR)-transgenic DO11.10 mouse allergic model. Splenocytes from coffee-administered naïve mice increased antigen (Ag)-specific interleukin (IL)-12p40 secretion. When Ag sensitization and coffee administration were concurrently performed, the splenocytes from coffee-administered mice showed a decrease of IL-2 and an increase of IL-12p40 secretion. The Ag-specific cutaneous response and serum IgE level were reduced in coffee-administered mice, although, after establishing the allergy, coffee administration did not suppress the allergic reaction.

These results suggest that coffee could induce a Th1-type response of the immune system and prevent an allergy developing. Further studies on the optimum dose, cultivar differences, and roasted degree need to be undertaken.     

Establishment of a Novel Method of Screening Anti-Allergic Lactic Acid Bacteria

In this study, we attempted to establish a novel method of screening anti-allergic lactic acid bacteria (LAB). We cloned the human histidine decarboxylase (HDC) promoter into the promoter-less pPhi-Yellow-RPL-dest1 vector and established KU812F cells transduced with this vector (pHDCp-Phi-Yellow/KU812F). After adding LAB to these cells, the change in fluorescence intensity was monitored by flow cytometry. After screening, we identified several LAB strains that downregulated HDC promoter activity. Functional analysis of these LAB strains indicated that two LAB strains inhibited histamine release from KU812F cells, indicating that this assay system can be used to screen for anti-allergic LAB in a high-throughput manner.     

Engineered recombinant ovomucoid third domain can modulate allergenic response in Balb/c mice model

IgE-mediated allergic reactions to egg white are a serious health problem and ovomucoid being the dominant egg white allergen has been on focus in the past decade. Engineered hypoallergens with reduced reactivity for IgE antibodies are being examined to modulate the allergic response and develop prophylactic allergen vaccines. In this study, we evaluated the immunomodulatory effect of a genetic variant of the third domain of ovomucoid (GMFA) which showed reduced IgE binding with egg allergic patient's sera in comparison to the native form of the third domain of ovomucoid (DIII) in a murine model system. Balb/c mice were injected intraperitoneally with DIII and GMFA antigens. Allergen-specific serum IgG, IgG1, IgG2a, and IgE responses were evaluated using enzyme-linked immunosorbent assay. Splenocyte cytokine levels in the medium of the cultured cells were examined by ELISA and levels of IL-4, INF-gamma, and IL-12 (p70) cytokines were quantified. Neutralization with anti-IL-12 monoclonal antibody was assayed and cytokine levels with respect to GMFA mutant antigen stimulation were measured. GMFA mutant form was found to have significantly reduced levels of specific IgE when compared to the DIII suggesting a mutation-induced abrogation of the IgE binding epitope in mice. The increase in IgG2a levels in GMFA together with the decline of IgE and IgG1 points to a shift from a Th2 response to a Th1 dominated response. The cytokine profile showed a modulation of anti-allergic Th1 phenotype in GMFA from a proallergic Th2 response observed with DIII. Low levels of IL-4 and increased levels of INF-gamma and IL-12 were observed and anti-IL-12 monoclonal antibody restored the levels of IL-4 and suppressed levels of INF-gamma and IL-12 in the GMFA sensitized group. These results indicate that GMFA has a marked suppressive effect on the allergic response of ovomucoid and caused a shift towards a Th1 pathway, thereby modulating the Th1/Th2 cytokine balance and could be used as a potential hypoallergenic candidate for allergen-immunotherapy in the treatment of egg white allergy.     

轮状病毒致乳鼠肠道外感染Th1/Th2细胞因子变化的研究

目的通过复制轮状病毒（RV）肠道外感染乳鼠的动物模型,检测接种后乳鼠体内Th1/Th2平衡改变,对RV肠道外感染后机体免疫状态进行初步研究。方法48只乳鼠随机均分为3组：肠道外组、肠道内组和正常对照组。肠道外组通过腹腔注射猴RVSA11株,肠道内组灌胃等量RV悬液,对照组无特殊处理。分别在接种后第4天、第8天处死乳鼠,收集标本,观察心、肝、肾、肺等脏器病理变化,用ELISA法检测血清中IL-10和IFN-γ的表达。结果光镜下肠道外组乳鼠肾、肝、肺和脾脏出现病理改变。感染后第4天,肠道内、外组乳鼠血清IFN-γ水平均高于正常组,到第8天明显下降,基本达到基线水平;IL-10在肠道外组第4天增高,到第8天小幅下降,但仍然高于正常组;而肠道内组IL-10无明显改变。结论RV肠道外感染早期呈现Th1-Th2混合反应,而后期则以IL-10的表达为主,T细胞向Th2型免疫应答方向偏离,Th1/Th2细胞因子失衡机制可能是RV肠道外感染的重要因素。     

沙门菌- 斑马鱼感染模型用于Th1/Th2 免疫应答的研究

目的:通过构建斑马鱼成鱼感染模型,研究鼠伤寒沙门菌感染对机体Th1/Th2免疫应答的影响。方法:用不同剂量细菌口饲感染8月龄的斑马鱼成鱼,绘制3周生存率曲线。观察各剂量下对成鱼的感染情况,并用实时荧光定量聚合酶链式反应检测肝脏Th1、Th2型细胞相关基因和细胞因子的mRNA转录水平,计算Th2/Th1相对表达量比值。结果:用105 CFU感染2周斑马鱼全部存活,第15天开始出现死亡,且在3周后死亡率达到50%;感染后3周解剖发现,肝脏、脾脏和肠道有明显红肿和糜烂;肝脏Th1、Th2型细胞相关基因和细胞因子mRNA转录水平明显向Th2偏移。结论:用105 CFU鼠伤寒沙门菌口饲感染斑马鱼成鱼构建的模型,能反映机体感染和免疫功能变化,可用于研究体内Th1/Th2免疫应答,为进一步研究鼠伤寒沙门菌感染与免疫机制提供了很好的实验工具。     

骨化三醇对自身免疫性甲状腺炎大鼠T淋巴细胞亚群的影响

目的:研究骨化三醇对自身免疫性甲状腺炎模型大鼠甲状腺功能、甲状腺过氧化物酶抗体(TPOAb)、甲状腺球蛋白抗体(TGAb)及脾脏T淋巴细胞亚群的影响。方法:20只Lewis大鼠采用高碘饮水联合猪甲状腺球蛋白皮下注射的方法建立自身免疫性甲状腺炎动物模型。造模成功后大鼠随机分为模型组和骨化三醇组。经10周灌胃后,检测各组大鼠甲状腺功能三项、甲状腺抗体,流式细胞技术检测大鼠脾脏T淋巴细胞亚群的比例。结果:(1)与正常组相比,模型组及骨化三醇组大鼠促甲状腺激素(TSH)明显降低,血清游离甲状腺素(FT4)及TPOAb、TGAb明显升高,差异均具有统计学意义(P0.01);与模型组大鼠相比,骨化三醇组大鼠TPOAb、TGAb明显降低(P0.01);(2)与正常组相比,模型组大鼠表现为Th1、Th17细胞比例升高(P0.05),Th1/Th2、Th17/Treg比例升高(P0.05),与模型组相比,骨化三醇组大鼠Th1、Th17细胞比例降低(P0.05),Th2、Treg比例升高(P0.05),Th1/Th2、Th17/Treg比例降低(P0.01)。结论:骨化三醇可通过抑制Th1、Th17免疫亢进,改善Th1/Th2、Th17/Treg失调,改善自身免疫性甲状腺炎免疫反应。     

益生菌辅助防治过敏性疾病的研究进展

益生菌是一类在适当的摄入数量时会对宿主机体带来益处的活体微生物,其对于机体的免疫系统具有调节作用.研究表明,益生菌可以通过调节Th1/Th2平衡,增加宿主对相关抗原的口服耐受,从而缓解过敏性症状.本文综述了近十年来研究益生菌抗过敏作用在体外试验、动物实验和临床试验三方面的进展.     

Anti-P- and E-selectin therapy prevents abortion in the CBA/J x DBA/2J combination by blocking the migration of Th1 lymphocytes into the foetal-maternal interface

Leukocyte migration into inflamed tissues comprises dynamic interactions between immune and endothelial cells through events controlled by adhesion molecules, e.g., P- and E-selectins, which mediate Th1 cells recruitment after injury. Since miscarriage is known to be a Th1 event and selectins are expressed at the murine foetal-maternal interface, the purpose of our study was to investigate whether blocking P- and E-selectins before implantation could inhibit Th1 migration into the foetal-maternal interface and thus prevent foetal rejection. DBA/2J-mated CBA/J females were treated with monoclonal antibodies (mAbs) against P-selectin or with both, anti-P- and anti-E-selectins combined on days 2 and 4 of pregnancy. PBS-treated females served as controls. Our data revealed a significant improvement in pregnancy outcome in both treated groups compared to the control, which is due to the effectiveness of the mAb against P-selectin, since the treatment with anti-E-selectin alone could not prevent abortion. We further observed that there was diminished Th1 cytokine production by decidual immune cells in all treated groups in comparison to the controls. Our data first confirm the important role of P-selectin in mediating the extravasation of abortive cells, while opening new therapeutic opportunities.     

Th1/Th2平衡调节与疾病发生的研究进展

正常情况下,辅助性T淋巴细胞亚群Th1/Th2细胞处于平衡状态,Th1/Th2平衡失调并向Th1或Th2状态转化的趋势称为Th1/Th2的漂移。习惯上把Th1及其细胞因子占优势的状态称为Th1状态,Th2及其细胞因子占优势的状态称为Th2状态。Th1/Th2平衡影响细胞因子网络的平衡,与许多疾病的发生、发展、治疗、转归有密切的关系。现就Th1/Th2平衡与人类相关疾病间的关系及相关研究作一综述。     

青贮饲料的研究、发展及现状

我国从上世纪50年代开始对青贮饲料技术进行研究和推广,但受当时生产水平和经济条件等因素制约,工作多属于生产性试探,对青贮饲料发酵机制,二次发酵问题及防腐措施等方面的研究甚少。在我国,主要以利用黄秸秆为饲料,而鲜青贮饲料的利用和推广尚有一定困难。     

Lactic acid bacteria in the quality improvement and depreciation of wine

The winemaking process includes two main steps: lactic acid bacteria are responsible for the malolactic fermentation which follows the alcoholic fermentation by yeasts. Both types of microorganisms are present on grapes and on cellar equipment. Yeasts are better adapted to growth in grape must than lactic acid bacteria, so the alcoholic fermentation starts quickly. In must, up to ten lactic acid bacteria species can be identified. They belong to the Lactobacillus, Pediococcus, Leuconostoc and Oenococcus genera. Throughout alcoholic fermentation, a natural selection occurs and finally the dominant species is O. oeni, due to interactions between yeasts and bacteria and between bacteria themselves. After bacterial growth, when the population is over 10⁶CFU/ml, malolactic transformation is the obvious change in wine composition. However, many other substrates can be metabolized. Some like remaining sugars and citric acid are always assimilated by lactic acid bacteri a, thus providing them with energy and carbon. Other substrates such as some amino acids may be used following pathways restricted to strains carrying the adequate enzymes. Some strains can also produce exopolysaccharides. All these transformations greatly influence the sensory and hygienic quality of wine. Malic acid transformation is encouraged because it induces deacidification. Diacetyl produced from citric acid is also helpful to some extent. Sensory analyses show that many other reactions change the aromas and make malolactic fermentation beneficial, but they are as yet unknown. On the contrary, an excess of acetic acid, the synthesis of glucane, biogenic amines and precursors of ethylcarbamate are undesirable. Fortunately, lactic acid bacteria normally multiply in dry wines; moreover some of these activities are not widespread. Moreover, the most striking trait of wine lactic acid bacteria is their capacity to adapt to a hostile environment. The mechanisms for this are not yet c ompletely elucidated . Molecular biology has provided some explanations for the behaviour and the metabolism of bacteria in wine. New tools are now available to detect the presence of desirable and undesirable strains. Even if much remains unknown, winemakers and oenologists can nowadays better control the process. By acting upon the diverse microflora and grape musts, they are more able to produce healthy and pleasant wines.     

原发性肝癌患者Th1/Th2 亚群研究*

目的:探讨原发性肝癌患者血清中淋巴细胞亚群中Th1/Th2的变化,为分析肝癌的发生发展状症和临床治疗提供免疫学指标。方法:应用放射免疫分析及酶联免疫分析法(ELISA),测定46例肝癌患者,及43例正常对照组进行比较。以IL-2、INF-γ和TNF-α水平代表Th1型细胞因子,以IL-4,IL-6、IL-8、IL-10的水平代表Th2型细胞因子。结果:肝癌患者IL-2、TNF-γ、IL-6的水平明显低正常对照组,P<0.01。IL-4、IL-8、IL-10、TNF-α的水平明显高于正常对照组,P<0.01。结论:肝癌患者体内存在Th1/Th2细胞因子失衡,其中Th1亚群功能抑制,Th2亚群功能亢进,其与肿瘤在宿主体内生长密切相关。通过纠正这些免疫失调将成为肝癌治疗的重要手段。