香菇多糖对急性弓形虫感染过程中CD4+CD25+Foxp3+调节性T细胞的调节作用研究

目的 探讨香菇多糖(Lentinan,Lent)对急性弓形虫感染BALB/c小鼠CD4+ CD25+ Foxp3+调节性T细胞(Tregs)数量和功能的调节作用.方法 对RH强毒株感染的BALB/c小鼠进行不同时间点的Lent预处理,动态观察用药后各组感染小鼠的生存率;在感染后第0、3、5、8和10天提取小鼠的脾细胞,FACS检测Tregs细胞数量的动态变化,ELISA法检测脾细胞培养上清中IL-10的分泌水平.结果 感染前6 d 1 mg/kg Lent用药组与药物未处理组相比显著提高了弓形虫感染小鼠的生存率;具有免疫抑制功能的Tregs数量于感染后8d达峰值,同时免疫应答中关键细胞因子IL-10的分泌水平也于感染后8d和10d显著增加.结论 对急性弓形虫感染的BALB/c小鼠采用Lent预处理之后能有效的调节Tregs的数量和功能,从而调控Th1/Th2之间的动态平衡达到治疗弓形虫的作用,为弓形虫病的临床治疗提供的新的理论依据.     

Th1/Th2细胞免疫应答在抗白念珠菌感染中的作用

白念珠菌是常见的条件致病性真菌,Th细胞激活的亚群类型决定了机体抗白念珠菌的特异性细胞免疫结果。当Th1细胞激活,机体对白念珠菌有抵抗力;而当Th2细胞激活,机体对白念珠菌易感。由Th1细胞分泌或能刺激Th1细胞分化的IFN－γ、IL－2、IL－12等细菌因子增强机体对白念珠菌的抵抗力;而Th2细胞分泌的IL－4、IL－10等细菌因子则相反。     

香菇多糖提取分离的研究

采用DEAE—cellulose柱层析和Sephadex G-200柱层析从香菇子实体热水浸提的粗多糖中分离出两个多糖组分Lenl—A、Len2-A,经旋光度法、Sepharose 4B柱层析、红外光谱等方法检测确定为均一多糖组分,且均为α-构型的吡喃糖,苯酚硫酸法测得其糖质量分数分别为91．5％和92．3％,旋光度为＋5．6°、＋11．2°,相对分子质量为375×10^3、718×10^3。     

双歧杆菌联合香菇多糖对肝硬化患者生理功能调节作用的研究

目的观察双歧杆菌联合香菇多糖治疗肝硬化患者的效果。方法肝硬化患者在接受常规保肝治疗的同时予口服双歧杆菌活菌胶囊联合香菇多糖胶囊。观察随访4周,治疗前后均抽取静脉血检测。采用常规方法检测肝功能;ELISA方法检测IFN-γ和IL-10水平的变化,流式细胞仪检测CIM／CD8细胞亚群的数量变化。结果临床一般状况明显好转,治疗前后部分肝功能指标明显改善。肝硬化组治疗前外周血CIM-γ细胞数量和IFN-1水平均显著低于正常对照组,治疗后二者明显升高,与治疗前相比差异有显著性。另外,与治疗前组相比,IL-10的水平治疗后明显降低。结论对于肝硬化患者,如果出现了明显的菌群失调伴随免疫功能低下者,宜采用微生态制剂联合免疫增强剂辅助治疗,临床效果较好。     

香菇多糖对微生态失调小鼠肠道菌群及免疫功能的调节作用

目的 探讨香菇多糖对微生态失调小鼠肠道菌群及免疫功能的调节作用.方法 经盐酸林可霉素灌胃建立肠道微生态失调小鼠模型,香菇多糖灌胃治疗,同时设正常对照组、自然恢复组和丽珠肠乐组.7d后处死各组小鼠,进行肠道菌群定量、免疫器官体重及其淋巴细胞转化率检测.结果 用香菇多糖对肠道微生态失调小鼠进行治疗后,小鼠肠道双歧杆菌、乳酸杆菌数量显著增加,而肠杆菌和肠球菌的数量显著降低;脾脏指数明显增加,对胸腺指数无影响;显著增强了淋巴细胞转化率.结论 盐酸林克霉素灌胃能诱导微生态失调小鼠模型的有效建立.香菇多糖能调整小鼠肠道菌群及免疫功能.     

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。     

复合酶解法提取香菇多糖蛋白的研究

存在于香菇中的多糖物质,具有增强人体非特异性免疫功能的作用。本文报道采用复合酶解和热水浸提法分离纯化香菇中多糖蛋白的综合程序。与单纯热水浸提法等其它方法相比,本法能显著提高香菇有效成分的浸提效果,总氨基酸与必需氨基酸百分比含量均提高２倍以上,香菇多糖含量提高了４倍,一些特殊成分及较高分子量的葡聚糖物质含量也明显提高。     

香菇多糖体内抗氧化活性研究

目的：探究香菇多糖的体内抗氧化活性。方法：以灌胃生理盐水的小鼠为正常对照组,将香菇多糖药物组分为低、中、高3种剂量组。小鼠在灌胃3w后,由眼眶取血,按照试剂盒要求测定小鼠血清中超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH-Px）活力以及丙二醛（MDA）含量。结果：香菇多糖可显著提高小鼠血清中SOD和GSH-Px的活力,同时减少血清中MDA含量。结论：香菇多糖对小鼠体内抗氧化活性的提高具有显著作用。     

香菇多糖对小鼠骨髓树突状细胞表型和功能的影响

通过研究香菇多糖(Lentinan,LNT)对小鼠骨髓源树突状细胞(bone marrow dendritic cells,BMDCs)功能调节的机制,进一步阐明香菇多糖的免疫活性。本实验将BMDCs分成脂多糖(LPS)阳性对照组、LNT处理组和RPMI1640空白对照组,应用酸性磷酸酶活性检测、流式细胞仪检测技术、吞噬实验、酶联免疫吸附试验检测各组BMDCs表型和功能的各种指标。结果显示,LNT(50μg/mL)处理组BMDCs酸性磷酸酶活性降低;BMDCs吞噬能力比RPMI1640空白对照组明显下降;BMDCs表面MHCⅡ、CD40、CD83、CD80、CD86和DEC205的表达增加;BMDCs白细胞介素12(IL-12)、白细胞介素10(IL-10)和肿瘤坏死因子-α(TNF-α)的表达增加。证明了适宜浓度的LNT可以促进BMDCs表型及功能的成熟。     

灵芝多糖对小鼠细胞免疫功能调节作用的实验研究

研究灵芝多糖 (GLB7)对小鼠细胞免疫功能调节作用的影响。实验小鼠分成 4组 ,分别经胃灌注不同剂量 (高、中、低 )灵芝多糖 ,每天 1次 ,连续 14d ,对照组小鼠用以等量蒸馏水代替。分别于实验第 15 ,2 8d进行小鼠细胞免疫功能调节作用的测试。灵芝多糖喂药后 2周 ,3个剂量组小鼠脾淋巴细胞转化试验、小鼠腹腔巨噬细胞对鸡血红细胞的吞噬百分率和吞噬指数 ;低剂量组小鼠迟发型变态反应 (DTH)、小鼠碳廓清 ;高剂量组小鼠NK细胞活性和对照组比较均有显著性差异 (P <0 .0 5 )。喂药后 4周 :上述实验结果和对照组比较均无显著性差异 (P >0 .0 5 )。结果提示灵芝多糖能提高小鼠的非特异性和特异性细胞免疫功能。     

Leishmania infantum: mixed T-helper-1/T-helper-2 immune response in experimentally infected BALB/c mice

The main goal of the present study was to characterise the course of infection and immunological responses developed by Leishmania infantum infected BALB/c mice. Parasite load was determined by Real-time TaqMan PCR while cytokine and Immunoglobulin G (IgG) production were assessed by ELISA. Leishmania DNA was detected in spleen and liver as soon as day 1 post-inoculation (pi) and the parasitism was sustained until the end of the experiment. The cytokine kinetics in spleen and liver was generally associated with the oscillations of parasite load. Overall, it was not observed a distinct Th1 or Th2 pattern of cytokine production during the time of experiment. The infected mice developed a mixed immune response, with concomitant production of IFN-gamma, IL-4 and IL-10, both in spleen and liver, and both IgG isotypes. However, our results suggest that, compared to liver, the spleen is more susceptible to L. infantum infection.     

Toxoplasma gondii: protective immunity against toxoplasmosis with recombinant actin depolymerizing factor protein in BALB/c mice

Toxoplasmosis is one of the most world-wide spread zoonosis representing a very serious clinical and veterinary problem. There is still need for vaccines for toxoplasmosis. In the present study, we evaluated the protective efficacy of a recombinant actin depolymerizing factor (ADF) subunit vaccine against Toxoplasma gondii infection in BALB/c mice. The recombinant T. gondii ADF protein (rADF) was expressed in Escherichia coli and used as antigens for BALB/c mice immunization. The results indicated that specific antibody and the increased percentage of CD4(+) T lymphocyte were found in vaccinated BALB/c mice with rADF, when compared with adjuvant or PBS groups. After challenged with T. gondii (RH strain) tachyzoites, the survival time of the mice in rADF group was longer than those in the control group. The numbers of brain cysts of the mice in rADF group reduced significantly when compared with those in control groups (P<0.05), and the rate of reduction could reach to around 30%. These results suggest that rADF can generate protective immunity against T. gondii infection in BALB/c mice.     

Taenia crassiceps antigens induce a Th2 immune response and attenuate injuries experimentally induced by neurotoxoplasmosis in BALB/c mice

Toxoplasma gondii is a pathogenic agent responsible for causing both systemic and local disease which elicits a typically pro-inflammatory, Th1 immune response. Taenia crassiceps antigen induces a Th2 immune response that immunomodulates Th1 based infections. Therefore the aim of this study was to evaluate whether T. crassiceps cysticerci antigens are able to modulate the inflammatory response triggered in experimental neurotoxoplasmosis (NT). BALB/c mice were inoculated with T. gondii cysts and/or cysticerci antigens and euthanized at 60 and 90 days after inoculation (DAI). The histopathology of the brains and cytokines produced by spleen cells culture were performed. The animals from the NT group, 90DAI (NT90), presented greater intensity of lesions such as vasculitis, meningitis and microgliosis and cytokines from Th1 profile characterized by high levels of IFN-gamma. While in the T. crassiceps antigens group, 60DAI, there were more discrete lesions and high levels of IL-4, a Th2 cytokine. In the NT co-inoculated with cysticerci antigens group the parenchyma lesions were more discrete with lower levels of IFN-gamma and higher levels of IL-4 when compared to NT90. Therefore the inoculation of T. crassiceps antigens attenuated the brain lesions caused by T. gondii inducing a Th2 immune response.     

Impact of dietary gluten on regulatory T cells and Th17 cells in BALB/c mice

Dietary gluten influences the development of type 1 diabetes (T1D) and a gluten-free (GF) diet has a protective effect on the development of T1D. Gluten may influence T1D due to its direct effect on intestinal immunity; however, these mechanisms have not been adequately studied. We studied the effect of a GF diet compared to a gluten-containing standard (STD) diet on selected T cell subsets, associated with regulatory functions as well as proinflammatory Th17 cells, in BALB/c mice. Furthermore, we assessed diet-induced changes in the expression of various T cell markers, and determined if changes were confined to intestinal or non-intestinal lymphoid compartments. The gluten-containing STD diet led to a significantly decreased proportion of γδ T cells in all lymphoid compartments studied, although an increase was detected in some γδ T cell subsets (CD8(+), CD103(+)). Further, it decreased the proportion of CD4(+)CD62L(+) T cells in Peyer's patches. Interestingly, no diet-induced changes were found among CD4(+)Foxp3(+) T cells or CD3(+)CD49b(+)cells (NKT cells) and CD3(-)CD49b(+) (NK) cells. Mice fed the STD diet showed increased proportions of CD4(+)CD45RB(high+) and CD103(+) T cells and a lower proportion of CD4(+)CD45RB(low+) T cells in both mucosal and non-mucosal compartments. The Th17 cell population, associated with the development of autoimmunity, was substantially increased in pancreatic lymph nodes of mice fed the STD diet. Collectively, our data indicate that dietary gluten influences multiple regulatory T cell subsets as well as Th17 cells in mucosal lymphoid tissue while fewer differences were observed in non-mucosal lymphoid compartments.     

Role of Toxoplasma gondii HSP70 and Toxoplasma gondii HSP30/bag1 in antibody formation and prophylactic immunity in mice experimentally infected with Toxoplasma gondii.

Production of antibodies against Toxoplasma gondii (T. gondii)-derived stress proteins, T. gondii HSP70 (T.g.HSP70) and T.g.HSP30/bagl, in C57BL/6 and BALB/c mice perorally infected with cysts of the avirulent Fukaya strain of T. gondii was analyzed. Production of anti-T.g.HSP70 IgG antibodies was transient, whereas production of anti-T.g.HSP30/bag1 IgG antibodies persisted after infection in both C57BL/6 and BALB/c mice. C57BL/6 mice, a susceptible strain, predominantly produced IgG antibodies specific for T.g.HSP70, whereas BALB/c mice, a resistant strain, predominantly produced IgG antibodies specific for T.g.HSP30/bag1, after T. gondii infection. Immunization with rT.g.HSP30/bag1 enhanced, whereas immunization with rT.g.HSP70 reduced host protective immunity against T. gondii infection with a cyst-forming avirulent strain, Fukaya, and a virulent strain, RH.     

Interleukin-18 enhances a Th2 biased response and susceptibility to Leishmania mexicana in BALB/c mice

Interleukin-18 deficient mice on a BALB/c background display increased resistance to cutaneous infection with Leishmania mexicana, with reduced lesion progression and reduced parasite burdens compared with wild-type mice. Infected IL-18-/- mice had lower antigen specific IgG1 levels and total IgE levels and conversely higher antigen specific IgG2a levels than similarly infected wild-type mice. Splenocytes isolated from infected IL-18-/- mice produced significantly lower levels of antigen induced IL-4 and higher levels of IFN-gamma than wild-type animals. Consequently IL-18 during L. mexicana infection of BALB/c mice promotes a Th2 biased response and thereby has a disease exacerbating role.