抗环子孢子蛋白保守II+区单克隆抗体的制备及鉴定

目的　获得针对恶性疟原虫环子孢子蛋白 (CSP)保守II⁺ 区 (RegionII⁺ )的单克隆抗体。　方法　采用恶性疟原虫保守II⁺ 区十二肽 (EWSPCSVTCGNG)免疫BALB/c小鼠 ,经融合 ,ELISA 3次筛选 ,获得 3株分泌针对保守II⁺ 区单克隆抗体的杂交瘤细胞株。　结果　ELISA检测结果显示单抗能与重组表达的恶性疟原虫CSP片段及天然CSP特异性反应。间接荧光抗体检测显示 ,单抗不仅能识别恶性疟原虫子孢子 ,也能识别约氏疟原虫子孢子。　结论　成功地获得了针对恶性疟原虫CSP保守II⁺ 区的单克隆抗体。     

ELISA检测云南按蚊环子孢子蛋白的评价

目的　采用酶联免疫吸附测定(ELISA)技术检测疟疾媒介按蚊环子孢子蛋白(CSP),评价ELISA用于云南疟疾媒介按蚊传疟效能调查的可行性。　方法　现场捕获疟疾媒介按蚊经产蚊,每只蚊镜检3叶唾腺子孢子感染率,ELISA检测另3叶唾腺CSP;用含间日疟原虫配子体的患者血人工喂饲微小按蚊,11d后同法镜检唾腺子孢子感染率及ELISA检测唾腺CSP。在种植场捕获8种按蚊(微小按蚊、中华按蚊、多斑按蚊、迷糊按蚊、可赫按蚊、带足按蚊、菲律宾按蚊和须喙按蚊 )各龄成蚊,ELISA检测唾腺CSP。　结果　①现场捕获经产蚊1010只,镜检唾腺子孢子阳性7只,阳性率为0.69%;ELISA检测唾腺CSP阳性8只,阳性率为0.79%;其中6只蚊两项检测均为阳性,阳性率为0.59%。两法比较,差异无显著性意义(P>0.05)。②人工感染36只微小按蚊,镜检唾腺子孢子阳性27只,阳性率为75.0%;ELISA检测唾腺CSP阳性29只,阳性率为80.6%;其中有26只蚊两项检测(Pv2 10CSP)均阳性,阳性率为72.2%。两法比较,差异无显著性意义(P>0.05)。③种植场捕获8种按蚊各龄成蚊4675只,ELISA检测唾腺CSP阳性11只,阳性率为0.24%;其中Pv210阳性9只,Pf2A10阳性2只;微小按蚊、中华按蚊和多斑按蚊ELISA检测阳性     

海南省间日疟原虫环子孢子蛋白基因分型及地理分布

目的 确定海南省疟区间日疟原虫环子孢子蛋白（CSP）基因型及地理分布,为制定合理的防治对策提供科学依据。方法 采用套式等位特异聚合酶链反应（PCR）技术,检测在海南省疟区内感染的间日疟病人滤纸血滴样本。结果 在99份受检血样中,有54份显示约700bp和约180bp二条扩增带,为温带族虫株,占54.54%;33份显示约700bp扩增带,为热带族虫株,占33.33% ;12份显示约700bp和588bp两条扩增带,为PV-2型虫株,占12.12%。结论 海南省流行的间日疟原虫CSP呈多态性,且存在地理分布差异。     

疟原虫环子孢子蛋白的研究进展

环子孢子蛋白(circumsporzoite protein,CSP)是疟原虫成熟子孢子表面的锚定蛋白,约含400个氨基酸,由N端保守I区、种属特异性的中央重复区和C端保守Ⅱ区构成。CSP在疟原虫的迁移、靶细胞入侵和增殖过程中发挥重要作用。近年研究显示,CSP在疟疾疫苗和靶向给药系统中具有良好的应用前景。本文对疟原虫CSP的结构特征、功能及其应用前景作一综述。     

间日疟原虫环子孢子蛋白基因片段的体外扩增,鉴定民克隆

目的：体外扩增、鉴定并克隆间日疟原虫环子孢子蛋白（ＣＳＰ）基因约７７２ｂｐ的基因片段，包容ＣＳＰ基因的Ⅰ区、中央９肽重复区、重复后可变区及Ⅱ区。方法：采用ＰＣＲ法扩增出ＣＳＰ目的基因片段，以低熔点琼脂糖回收纯化，并以限制必丙切酶ＢｓｔＮＩ酶发鉴定后，采用Ｔ载体连接方案，插入中间体载体ＰＵＣ１９的多克隆位点，构建重组体ＰＵＣ１９／ＣＳＰ，并转化大肠杆菌ＪＭ１０７，蓝白菌斑初筛阳性重组子，并以ＰＣＲ法     

广西间日疟原虫环子孢子蛋白基因型的初步研究

目的：了解广西间日疟原虫种群的基因型组成及其地理分布。方法 用滤纸法采集经镜检确诊的间日疟原虫阳性病人血样31份，Chelex-100离子交换法用于提取滤纸血样中的DNA，改进的套式－等位特异－PCR和琼脂糖凝胶电泳用于鉴别性片段的扩增，分析和鉴定。结果 在19份广西当地间日疟病例血样中17份鉴定为温带族虫株（89．5％），2份为热带族株（10．5％）；12份输入病例血样中，温带族8份（66．7％），热 带型3份（25．0％）PV－2型1份（8．3％）。结论 目前广西当地流行的间日疟以温带族虫株为主，少数热带族病例出现在环江和防城县，但输入间日疟病例中热带族虫株感染占较大比例。     

恶性疟原虫环子孢子蛋白基因在大肠杆菌中的表达

用ＰＣＲ方法特异性扩增恶性疟原虫云南株（ＰＦＤ－３／ＹＮ）环子孢子蛋白基因片段,经基因序列测定后克隆于ｐＷＲ４５０－１融合蛋白表达载体,并转化大肠杆菌ＴＧ１、ＪＭ１０３及ＪＭ１０９。在不同菌体浓度及不同剂量ＩＰＴＧ诱导下检测ＣＳＰ融合蛋白的表达,结果显示仅ｐＷＲ－ＣＳＰ／ＴＧ１工程菌在菌体浓度ＯＤ５９０值达０．７～０．８时,加入终浓度１ｍｍｏｌ／ＬＩＰＴＧ进行诱导,可表达一８８ｋＤａ的融合蛋白。ｄｏｔ－ＥＬＩＳＡ和Ｗｅｓｔｅｒｎｂｌｏｔ分析表明ＣＳ蛋白表达产物能被抗ＣＳ蛋白重复区单克隆抗体所识别     

单克隆抗体对间日疟原虫子孢子入侵培养细胞及…

本文在体外观察了抗间日疟原虫子孢子的单克隆抗体２Ｆ２，ＮＶＳ３和２Ｅ１０以及抗间日疟原虫红内期单克隆抗体４Ｂ２，８Ｅ３对日疟原虫子孢子入侵入肝癌细胞以及侵入后的进一步发育的影响。     

海南省间日疟原虫环子孢子蛋白基因分型及地理分布

目的确定海南省疟区间日疟原虫环子孢子蛋白(CSP)基因型及地理分布,为制定合理的防治对策提供科学依据.方法采用套式等位特异聚合酶链反应(PCR)技术,检测在海南省疟区内感染的间日疟病人滤纸血滴样本.结果在99份受检血样中,有54份显示约700 bp和约180 bp二条扩增带,为温带族虫株,占54.54%;33份显示约700bp扩增带,为热带族虫株,占33.33%;12份显示约700 bp和588 bp两条扩增带,为PV-2型虫株,占1 2.1 2%.结论海南省流行的间日疟原虫CSP呈多态性,且存在地理分布差异.     

Fine specificities of monoclonal antibodies against the Plasmodium falciparum circumsporozoite protein: recognition of both repetitive and non-repetitive regions

The fine specificities of 6 monoclonal antibodies (MoAbs) raised against the circumsporozoite (CS) protein of the human malaria parasite, Plasmodium falciparum, were defined by their binding to a series of overlapping octapeptides corresponding to the 7G8 variant of the CS protein. The precise specificities of the MoAbs to the immunodominant NANP repeat region were elucidated by their binding to all possible 4, 5, 6, 7 and 8 amino acid peptides in this region. All 6 MoAbs recognized the NANP repeats. In addition all MoAb bound to nonrepetitive sites with 4 of the 6 MoAbs recognizing known functional sites outside the repeat region including sites required for T cell recognition and hepatocyte invasion. Antibody pressure may therefore be responsible for generating the epitope variation observed at T cell sites. The multiple specificities for all the MoAbs suggests that the repeat region may act as an internal immunological 'smokescreen' by competing more effectively for antibody binding compared to single epitope copy functional sites located outside the repeat region.     

重组恶性疟原虫醛缩酶鉴定及其单克隆抗体的制备

目的 鉴定重组表达的恶性疟原虫醛缩酶（ALD），制备针对此酶的单克隆抗体。 方法 用PCR法扩增恶性疟原虫海南株ALD基因，经大肠埃希菌表达并纯化的ALD免疫BALB/c小鼠，腹腔注射免疫3次,每次间隔2周，加强免疫后3d取免疫小鼠脾细胞制备单克隆抗体。同时用获得的免疫血清进行间接荧光抗体试验（IFAT）和蛋白质印迹（Westernt blotting）分析。 结果 ELISA检测表明，小鼠能产生较高的针对ALD免疫应答，3次免疫后血清中特异性抗体滴度达1∶10⁵，IFAT显示免疫血清能特异性识别疟原虫体内的抗原；Western blotting分析显示免疫血清识别的疟原虫蛋白相对分子质量（Mr）约41 000；所制备的免疫血清与人红细胞内醛缩酶无交叉反应。经ELISA检测 3次，筛选获得7株分泌针对ALD的单克隆抗体的杂交瘤细胞株，其中3株分泌的单克隆抗体能识别培养的恶性疟原虫；抗体亚型鉴定结果显示均为IgG1型。 结论 本实验构建并表达了重组疟原虫糖酵解醛缩酶，并获得特异性的单克隆抗体。     

Circumsporozoite protein of Plasmodium gallinaceum characterized by monoclonal antibodies

Monoclonal antibodies (MoAb) were produced against both salivary gland sporozoites (SGS) and oocyst sporozoites (OS) of Plasmodium gallinaceum, an avian malaria parasite. By indirect immunofluorescence, all of the MoAbs reacted with both SGS and OS of P. gallinaceum and two of the MoAbs cross-reacted weakly with P. berghei sporozoites. None of the MoAbs reacted with sporozoites of six additional species of mammalian plasmodia. In Western blot analysis of extracts of either SGS or OS of P. gallinaceum, these MoAbs identified two polypeptides with molecular weights of approximately 76,000 and 64,000 D. The results of a MoAb inhibition of binding assay and a two-site one-antibody immunoradiometric assay indicate that the circumsporozoite protein of P. gallinaceum, like those of mammalian malaria parasites, contains a repetitive immunodominant epitope. Two of the anti-P. gallinaceum MoAbs were tested in a sporozoite neutralization assay and decreased, but did not abolish, the infectivity of sporozoites for chickens, indicating that the polypeptide of P. gallinaceum identified by immunoblot is probably the protective antigen.     

恶性疟原虫融合抗原PfCP-2.9的单克隆抗体制备及功能分析

目的 制备恶性疟原虫（FCC1/HN株）融合抗原PfCP-2.9的单克隆抗体，分析其生物学特性及功能。 方法 用PfCP-2.9免疫BALB/c小鼠，取其脾细胞及SP2/0骨髓瘤细胞在聚乙二醇（PEG1500）作用下进行融合，制备单克隆抗体，并分析其特性。 结果 获得1株能分泌抗PfCP-2.9的小鼠杂交瘤细胞株单克隆抗体F12D，经免疫球蛋白类型和亚类鉴定为IgG1。ELISA和蛋白质印迹法（Western blotting）显示单克隆抗体F12D能与PfCP-2.9发生特异性反应，F12D所识别的PfCP-2.9抗原表位不能耐受还原剂巯基乙醇，表明F12D识别的是构象表位。间接免疫荧光试验（IFA）显示F12D可识别培养的FCC1/HN。体外抑制试验结果显示，F12D终浓度为0.3 mg/ml时，对FCC1/HN的抑制率为56%。 结论 单克隆抗体F12D能与PfCP-2.9发生特异性反应，其所识别表位为构象表位，F12D可识别体外培养的FCC1/HN，并对其生长具有抑制作用。     

Invasion of erythrocytes in vitro by Plasmodium falciparum can be inhibited by monoclonal antibody directed against an S antigen

A monoclonal antibody has been produced which binds to the heat stable S antigen present in the FCQ-27/PNG isolate of Plasmodium falciparum. This monoclonal antibody also inhibits the invasion in vitro of erythrocytes by malarial merozoites thus demonstrating that the S antigens of Plasmodium falciparum may be a target of protective immune responses.     

Development of Monoclonal Antibodies That Target 1-Cys Peroxiredoxin and Differentiate Plasmodium falciparum from P. vivax and P. knowlesi

Prompt and accurate diagnosis of malarial patients is a crucial factor in controlling the morbidity and mortality of the disease. Effective treatment decisions require a correct diagnosis among mixed-species malarial patients. Differential diagnosis is particularly important in cases of Plasmodium vivax, a species that shares endemicity with P. falciparum in most endemic areas. Moreover, it is difficult to identify P. knowlesi on the basis of morphology alone, and rapid diagnostic tests are still not available for this malaria species. Therefore, the development of diagnostic tests applicable to the field is urgently needed. 1-Cys peroxiredoxin (1-Cys-Prx) in P. falciparum is abundantly expressed in the mature asexual stages, making it a promising candidate as a diagnostic antigen. In this study, we produced five monoclonal antibodies (mAbs) against P. falciparum 1-Cys-Prx (Pf1-Cys-Prx) by immunizing BALB/c mice with recombinant Pf1-Cys-Prx and subsequent hybridoma production. Cross reactivity of established mAbs with the orthologous molecule of Pf1-Cys-Prx in P. vivax (Pv1-Cys-Prx) and P. knowlesi (Pk1-Cys-Prx) was examined. Western blot analyses showed that three mAbs reacted with Pv1-Cys-Prx and Pk1-Cys-Prx but two mAbs did not. These results indicate that the two mAbs were effective in differentiating P. falciparum from P. vivax and P. knowlesi and could be used in differential diagnosis as well as comparative molecular studies of human Plasmodium species.     

Plasmodium falciparum circumsporozoite protein: epidemiological variations among field isolates prevalent in India

Objective  To investigate the extent of genetic variations in T-helper-cell epitopic regions of circumsporozoite (CS) protein in Plasmodium falciparum field isolates collected from different regions of India at different phases of malaria transmission.
Methods  Genomic DNA was isolated from 507 P. falciparum wild-parasite isolates obtained from six geographical locations of India at three time points coinciding with malaria transmissions. The T-helper-cell epitopic regions were polymerase chain reaction (PCR)-amplified and the products were purified and then sequenced.
Results  Based on sequences, nine variants were found among isolates and they were categorized into nine groups (V-1 to V-9), where V-1 and V-2 were observed in all three time points (TP). The variants V-1 to V-4 in TP-1; V-1, V-2, V-5 to V-8 in TP-2; and V-1, V-2, V-5 and V-9 in TP-3 were present and they showed restricted heterogeneity. During peak transmission (TP-2), parasite populations were more diverse and heterogeneous and the variants regionally unbiased and restricted. However, the alleles of V-6 and V-9 in both Th2R and Th3R showed identical sequence variation with those observed in other geographical regions of the world. The remaining seven groups did not show such similarity.
Conclusion  The Th2R and Th3R epitopes are implicated in host immune response to P. falciparum . The polymorphism in these epitopic regions indicates antigenic diversity, which may cause adverse outcome of a subunit vaccine including the CS prototype variant. Therefore, the formulation of a vaccine considering the restricted local repertoire parasite populations may be helpful.     

恶性疟原虫乳酸脱氢酶特异性单克隆抗体的制备

目的制备恶性疟原虫乳酸脱氢酶特异性单克隆抗体。方法克隆、表达恶性疟原虫乳酸脱氢酶基因,并以表达的重组蛋白免疫BALB/c小鼠,采用杂交瘤技术制备单克隆抗体,对所制备的单克隆抗体确定其亚类和效价,蛋白质印迹法(Western blotting)分析其特异性。结果成功克隆并表达了恶性疟原虫乳酸脱氢酶基因,以重组恶性疟原虫乳酸脱氢酶蛋白作为免疫源制备单克隆抗体,共筛选了15株能高效分泌效价在1∶6 400～1∶51 200特异抗体的细胞株,抗体亚类为IgG1或IgG2。所有抗体均能唯一识别恶性疟原虫虫源蛋白Mr 33 000组分,而与疫区非疟疾发热病人的红细胞组分无交叉反应。结论以重组恶性疟原虫乳酸脱氢酶蛋白为免疫源成功制备了能识别天然恶性疟原虫乳酸脱氢酶蛋白的特异性单克隆抗体。     

Human monoclonal antibodies against Plasmodium falciparum: production, stabilization and characterization

Nine human monoclonal antibodies (MoAbs) recognizing 7 different antigenic structures of blood-stages of the human malarial parasite P. falciparum (Pf) were produced by Epstein-Barr virus transformed B-cell lines (EBV-TCL) with or without fusion to the lymphoblastoid cell line KR4. The peripheral blood B-lymphocytes were obtained from 8 Gambian donors immune to Pf malaria. Two of the EBV-TCL could be expanded and maintained for more than 6 months but neither one could be cloned. Six additional EBV-TCL were stabilized after fusion with the KR4 lymphoblastoid cell line. All resulting hybridomas permitted easy cloning. Some of the MoAbs produced distinct fluorescent staining patterns of asexual Pf blood-stage parasites when using high-resolution digitized video-intensified fluorescence microscopy. Antigens on 195 kD and 155 kD proteins were recognized by 3 and 1 MoAb, respectively, using Western blotting and immunoprecipitation techniques.