杜氏利什曼原虫无鞭毛体蛋白基因真核表达重组质粒构建

目的 构建杜氏利什曼原虫无鞭毛体蛋白（amastin）编码基因的真核表达重组质粒pcDNA3.1-amastin。方法 提取杜氏利什曼原虫基因组DNA进行PCR扩增,将扩增出的无鞭毛体蛋白基因片段导入质粒载体pcDNA3.1（＋）,构建真核表达重组质粒pcDNA3.1-amastin。结果 扩增出大小约550bp的无鞭毛体蛋白基因;重组质粒pcDNA3.1-amastin经鉴定正确。结论 成功构建杜氏利什曼原虫无鞭毛体蛋白基因真核表达重组质粒pcDNA3.1-amastin。     

杜氏利什曼原虫四川分离株无鞭毛体蛋白基因的克隆及真核表达

目的克隆、真核表达杜氏利什曼原虫四川株的无鞭毛体蛋白(amastin)编码基因。方法PCR扩增杜氏利什曼原虫四川汶川人株L．d．SC10H2与四川南坪犬株L．d．SC7的无鞭毛体蛋白基因,将该基因导入pcDNA3．1( ),构建真核表达重组质牲,转染NIH3T3细胞,采用免疫荧光法鉴定重组质粒的瞬时表达;RT-PCR和Western blotting鉴定稳定表达,结果2株杜氏利什曼原虫均扩增出552 bp的无鞭毛体蛋白基因。同源性为86％。转染后在NIH3T3细胞膜和细胞内观察到较强的绿色荧光,表明无鞭毛体蛋白基因在NIH3T3细胞中获得短暂表达。细胞裂解产物经Western blotting,在相对分子质量(Mr)约20000处检测到阳性杂交信号,表明无鞭毛体蛋白基因在NIH3T3细胞内获得了稳定表达。结论获得了我国杜氏利什曼原虫四川分离株L．d．SC10H2和L．d．SC7的无鞭毛体蛋白基因序列,并在NIH3T3细胞中稳定表达。     

杜氏利什曼原虫四川分离株无鞭毛体蛋白基因的克隆及真核表达

目的 克隆、真核表达杜氏利什曼原虫四川株的无鞭毛体蛋白（amastin）编码基因。 方法 PCR扩增杜氏利什曼原虫四川汶川人株L.d.SC10H2与四川南坪犬株L.d.SC7的无鞭毛体蛋白基因，将该基因导入pcDNA3.1（+），构建真核表达重组质粒，转染NIH3T3细胞，采用免疫荧光法鉴定重组质粒的瞬时表达；RT-PCR和Western blotting鉴定稳定表达。 结果 2株杜氏利什曼原虫均扩增出552 bp的无鞭毛体蛋白基因，同源性为86％。转染后在NIH3T3细胞膜和细胞内观察到较强的绿色荧光，表明无鞭毛体蛋白基因在NIH3T3细胞中获得短暂表达。细胞裂解产物经Western blotting，在相对分子质量（Mr）约20 000处检测到阳性杂交信号，表明无鞭毛体蛋白基因在NIH3T3细胞内获得了稳定表达。 结论 获得了我国杜氏利什曼原虫四川分离株L.d.SC10H2和L.d.SC7的无鞭毛体蛋白基因序列，并在NIH3T3细胞中稳定表达。     

杜氏利什曼原虫LACK抗原基因的克隆和表达

目的　在大肠杆菌中高效表达纯化杜氏利什曼原虫的LACK抗原。方法　以本实验室的重组质粒T -LACK为模板 ,PCR扩增得到LACK抗原基因 ,与表达载体pQE31定向重组 ,转化到宿主菌M 15中进行表达和纯化 ,并以SDS -PAGE和Western -blotting进行鉴定。结果　 1 SDS -PAGE电泳检测 ,重组质粒 pQE31-LACK的全菌蛋白没有出现明显的特异表达带 ,而纯化蛋白和包涵体溶解物在 36kDa处均出现了特异的表达带。 2 36kDa的纯化蛋白被抗利什曼原虫鼠血清清晰地识别。结论　得到了高效表达的LACK纯化蛋白 ,并有免疫原性     

杜氏利什曼原虫23kDa抗原编码基因克隆的表达

将已建立的杜氏利什曼原虫 c DNA文库基因 ,亚克隆于 p UC18质粒载体 ,诱导表达筛选两个克隆 ,即 P1、P2 ,表达的蛋白分子量皆为 2 3k Da,P1克隆表达的 2 3k Da蛋白分子 ,经 Western blot分析显示 ,可被兔抗杜氏利什曼原虫前鞭毛体抗血清及内脏利什曼病病人血清识别     

利什曼原虫胞内寄生相关基因的研究

利什曼病是由利什曼原虫无鞭毛体寄生在包括人在内的哺乳动物巨噬细胞而引起的疾病,由杜氏利什曼原虫引起的内脏利什曼病若不治疗则会致命.研究者对寄生在白蛉属消化道内的前鞭毛体和寄生在巨噬细胞内的无鞭毛体胞内高表达基因或蛋白进行研究,筛选出一些特异基因,为利什曼原虫疫苗候选抗原的确定和靶作用药物的确定提供了科学依据.     

利什曼原虫胞内寄生相关基因的研究

利什曼病是由利什曼原虫无鞭毛体寄生在包括人在内的哺乳动物巨噬细胞而引起的疾病,由杜氏利什曼原虫引起的内脏利什曼病若不治疗则会致命.研究者对寄生在白蛉属消化道内的前鞭毛体和寄生在巨噬细胞内的无鞭毛体胞内高表达基因或蛋白进行研究,筛选出一些特异基因,为利什曼原虫疫苗候选抗原的确定和靶作用药物的确定提供了科学依据.     

利什曼原虫胞内寄生相关基因的研究

利什曼病是由利什曼原虫无鞭毛体寄生在包括人在内的哺乳动物巨噬细胞而引起的疾病,由杜氏利什曼原虫引起的内脏利什曼病若不治疗则会致命.研究者对寄生在白蛉属消化道内的前鞭毛体和寄生在巨噬细胞内的无鞭毛体胞内高表达基因或蛋白进行研究,筛选出一些特异基因,为利什曼原虫疫苗候选抗原的确定和靶作用药物的确定提供了科学依据.     

不同种株利什曼原虫的比较蛋白质组学分析

目的观察不同种株利什曼原虫前鞭毛体蛋白质表达状况。方法制备杜氏利什曼原虫四川SC6株、杜氏利什曼原虫四川SC10株和硕大利什曼原虫5ASKH株前鞭毛体总蛋白,以pH范围3-10的预制胶条进行双向电泳(2-D),考马斯亮蓝染色,PDQust软件分析凝胶,主要差异蛋白点用电喷雾质谱法进行鉴定。结果等量的杜氏利什曼原虫四川SC6株、杜氏利什曼原虫四川SC10株和硕大利什曼原虫5ASKH株前鞭毛体总蛋白均获近700个蛋白点,不同种株利什曼原虫前鞭毛体蛋白质2-D图谱中,14蛋白点呈恒定差异表达,从中鉴定出10个功能明确的蛋白质,分别具有下列生物功能:糖代谢与磷脂合成(烯醇酶、变旋酶、NADP依耐乙醇脱氢酶、乙醇胺磷酸胞苷酸转移酶),压力反应(细胞内过氧化物酶、锥虫还原蛋白过氧化物酶),细胞膜/细胞骨架(α-微管蛋白、β-微管蛋白),核酸代谢(琥珀酰辅酶A连接酶(GDP形成)、内源性RNA酶L-PSP(pb5)),细胞周期与增殖(延伸因子2)。结论不同种株利什曼原虫前鞭毛体蛋白质的表达存在不同,为理解不同种株利什曼原虫的毒力、免疫原性和代谢特征提供了新的视角。     

应用免疫蛋白质组学方法鉴定日本血吸虫虫卵诊断抗原

目的虫卵可溶性抗原（soluble egg antigen,SEA）是目前日本血吸虫病免疫诊断中最常用的抗原。本研究联合应用双向凝胶电泳（2-DE）、Western blot和MALDI-TOF质谱等技术,鉴定SEA中诊断抗原蛋白质。方法 SEA经2-DE分离蛋白质后进行银染,或应用日本血吸虫感染兔血清Western blot筛选抗原蛋白点,用MALDI-TOF/TOF串联质谱鉴定每一抗原蛋白质分子。结果虫卵可溶性蛋白分子经2-DE分离后转印PVDF膜上,与感染兔血清孵育出现29个特异性阳性反应点,与健康兔血清出现3个非特异的阳性反应点;29个特异性抗阳性反应点中,从银染2-DE胶图上找到21个匹配的抗原蛋白质点;MALDI-TOF/TOF质谱鉴定和NCBI数据库检索,13个点（61.9%）获得匹配蛋白质,4个点（19.0%）获得匹配EST,4个点（19.0%）未能从数据库中找到相匹配的信息。重组表达筛选出的SjCHGC06040和SjP40两个抗原蛋白质,Western blot结果显示reSjCHGC06040、reSjP40均能与感染兔血清抗体发生特异性反应,具有潜在的应用价值。结论 2-DE、MALDI-TOF质谱联合Western blot的免疫蛋白质组学研究方法,用于筛选、鉴定SEA中诊断抗原蛋白质,是切实可行的;但该方法存在一定的局限性,有待进一步改进。     

杜氏利什曼原虫前鞭毛体和无鞭毛体的比较蛋白质组学分析

目的 应用蛋白质组学技术分析杜氏利什曼原虫前鞭毛体和无鞭毛体蛋白质表达状况。 方法 分别提取和纯化杜氏利什曼原虫四川SC6株前鞭毛体与纯培养无鞭毛体的总蛋白,分别经pH3～10的预制胶条进行双向电泳分离,凝胶用考马斯亮蓝染色,凝胶图像以PDQuest 1.0软件分析,并对主要差异表达蛋白点用电喷雾质谱法进行鉴定。 结果 等量的前鞭毛体与纯培养的无鞭毛体总蛋白经双向电泳分离后均可获近700个蛋白点,其中超过90%的蛋白点的分布和相对强度基本一致。与前鞭毛体比较,6个蛋白点在无鞭毛体蛋白中明显高表达,3个蛋白点低表达。6个明显高表达的蛋白点中有5个为已知功能蛋白,分别为Reiske铁硫蛋白前体、α微管蛋白、过氧化物酶1、二氢硫辛酰胺乙酰转移酶前体和甘露糖-1-磷酸瓜氨酸转移酶;3个低表达的蛋白点中有2个为已知功能蛋白,分别为热休克蛋白70和β微管蛋白。这些差异调节表达蛋白与碳水化合物/能量代谢,应激反应,细胞膜和细胞骨架形成相关。 结论 前鞭毛体与无鞭毛体蛋白质的表达存在差异。     

Characterization of intracellular metabolites of axenic amastigotes of Leishmania donovani by 1H NMR spectroscopy.

The intracellular metabolites of long-term in vitro cultured axenic amastigotes of Leishmania donovani (strain Dd8) were determined and compared with those of promastigotes and intracellular amastigotes, employing proton NMR spectroscopy. The presence of two new metabolites, i.e. betaine and beta-hydroxybutyrate were reported. Betaine was detected in all the three stages being highest in the promastigotes while beta-hydroxybutyrate could be detected only in promastigotes and axenic amastigotes. Among other metabolites, succinate and valine were found in higher quantities in intracellular amastigotes and axenic amastigotes than in promastigotes. Acetoacetate was present only in axenic and intracellular amastigotes. The comparative metabolite profile of different parasite forms reveals that axenic amastigotes seem to represent an intermediate stage between promastigotes and intracellular amastigotes in spite of their strong resemblance to intracellular amastigotes in morphology, infectivity, biochemical studies and even in the manifestation of amastigote specific A2 protein.     

不同种（株）利什曼原虫毒力相关基因的表达差异

目的 观察不同种（株）利什曼原虫前鞭毛体和无鞭毛体的毒力相关基因表达情况。 方法 制备杜氏利什曼原虫、婴儿利什曼原虫、热带利什曼原虫、硕大利什曼原虫和墨西哥利什曼原虫等5种7株利什曼原虫前鞭毛体和无鞭毛体的总RNA,采用半定量RT-PCR法,以α-微管蛋白基因和3-磷酸甘油醛脱氢酶基因（GAPDH）作为阳性对照,根据GenBank公布的GDP甘露糖焦磷酸酶基因（GDPMP）、A2抗原相关蛋白基因（A2rel）、脂磷酸多糖合成蛋白1基因（LPG1）、脂磷酸多糖合成蛋白2基因（LPG2）、动基体膜蛋白11基因（KMP-11）、胱氨酸蛋白酶C基因（CPC）、亲水性酰化表面蛋白B1基因（HASPB1）、胱氨酸蛋白酶2基因（CPB2）、胱氨酸蛋白酶B2.8基因（CPB2.8）和热激蛋白100基因（CLP b）等毒力相关基因的核苷酸序列,设计特异性引物进行RT-PCR扩增,分析以上各基因在各种（株）前鞭毛体和无鞭毛体中的表达情况。 结果 各毒力基因在不同种（株）利什曼原虫的前鞭毛体和无鞭毛体中的表达明显不同,HASPB1基因在7个种（株）利什曼原虫的无鞭毛体和杜氏利什曼原虫前鞭毛体中均表达,GDPMP、LPG1、LPG2、CPB2.8、CPB2、A2rel和CLP基因分别在特定种（株）的前鞭毛体和/或无鞭毛体中表达,CPC基因仅在杜氏利什曼原虫SC10株和硕大利什曼原虫无鞭毛体内表达,KMP-11基因在7个种（株）利什曼原虫前鞭毛体或无鞭毛体内均不表达。 结论 毒力相关基因的表达存在种特异性和期特异性。     

An experimental model for canine visceral leishmaniasis

Seven mixed-breed dogs were challenged with either promastigotes or amastigotes of Leishmania donovani infantum strains recently isolated from naturally infected dogs. Different routes and numbers of parasites were utilized and each dog was monitored for at least 1 year post-infection. Anti-parasite specific antibody levels were measured by enzyme-linked immunosorbence, immunofluorescence, crossed-immune electrophoresis and Western blotting on crude antigen. Western blotting on two pure parasite proteins, dp72 and gp70-2, was also done. Mitogenic and antigen-specific stimulation of peripheral blood lymphocytes was monitored; and the haematological, clinical and parasitological parameters measured. Dogs challenged with amastigotes exhibited a more pronounced humoral response to leishmanial antigens. Only in one case was strong antigen-specific proliferation detected. Clinical signs of disease, including hypergammaglobulinaemia, enlarged lymph nodes and the presence of parasites, were also more apparent in the dogs challenged with amastigotes. None of the seven dogs died. Serum antibodies to leishmanial antigens were apparent between 1.5 to 3 months following challenge and correlated with the appearance of enlarged lymph nodes, hypergammaglobulinaemia and the presence of parasites in tissue biopsies. Serum antibodies remained chronically high in these dogs throughout the period of the study. Only one dog (1/3) challenged intravenously with promastigotes and the dog challenged intradermally with amastigotes produced transient antibody responses to leishmanial antigen.     

Axenic cultivation of amastigotes of Leishmania donovani and Leishmania major and their infectivity.

Two clones of promastigotes, one of Leishmania donovani and one of L. major, and an uncloned stock of L. major were axenically transformed to heat-shock amastigotes, at 35 and 37 degrees C, respectively. Of the four different culture media tested, a relatively cheap, liquid medium, RBLM, was found to be the best, both for the transformation of the promastigotes and the serial, axenic cultivation of the amastigotes. In an experiment of 30 days duration, serial cultivation, in an atmosphere with 5% CO2, was possible by subculturing every three days. There were significant differences in virulence in BALB/c mice between axenically-cultured amastigotes and promastigotes, both in terms of the weights, lengths and parasite burdens of the spleens of mice infected intraperitoneally (ip) with L. donovani or L. major and of the appearance, type and size of the cutaneous lesions which developed in mice given L. major by intradermal inoculation.     

In vitro and in vivo anti-leishmanial activity of chlorpromazine alone and combined with N-meglumine antimonate

Chlorpromazine (CPZ) was effective in vitro against leishmanial promastigotes and amastigotes. CPZ at 7.5 micrograms ml-1 killed the promastigotes of Leishmania mexicana, L. aethiopica and L. major within 24 hours of exposure. A higher concentration was required to achieve the same effect against L. donovani. N-meglumine antimonate (MGA) was only partially effective against the promastigotes of the four strains studied. Even at 1000 micrograms ml-1 total destruction of the parasites did not occur within four days of treatment. Combination chemotherapy of CPZ and MGA generally showed an additive effect against promastigotes. However, a synergistic effect was observed in the case of L. donovani promastigotes and L. major amastigotes in vitro. No significant effect was obtained against the amastigotes of L. major and L. mexicana in vivo, in cutaneous lesions of BALB/c mice.     

The effect of liposome-entrapped desferrioxamine on Leishmania donovani in vitro

Desferrioxamine was tested in vitro for activity against promastigotes of Leishmania donovani. In addition, the effects of liposome-encapsulated desferrioxamine and free desferrioxamine on macrophages infected with amastigotes of L. donovani were compared. The drug was added to the culture medium for three days, and the results were compared with several controls; the drug solvent, empty liposomes, and desferrioxamine which had been re-ferrated with an equimolar concentration of ferric ammonium sulphate. Desferrioxamine was found to be inactive against growing promastigotes at the highest concentration used, 50 micrograms ml-1. On the other hand, 44% and 60% of amastigotes were eliminated when macrophages infected with L. donovani were exposed to 50 micrograms ml-1 of free or liposome-encapsulated desferrioxamine respectively.