恶性疟原虫FCC-1/HN株3-磷酸甘油醛脱氢酶基因的序列测定

目的：对恶性疟原虫FCC-1/HN株的3-磷酸甘油醛脱氢酶（GAPDH）基因进行序列测定。方法：恶性疟原虫FCC-1/HN株体外培养物提取总RNA和基因组DNA，从总RNA合成cDNA。分别用基因组DNA和cDNA作模板在体外用特异引物扩增GAPDH基因，并直接对其进行序列测定。结果：恶性疟 原虫GAPDH基因含一个约300bp的内含子，该基因的开放阅读框共1011bp,编码一个337氨基酸残基的蛋白质。结论：我国恶性疟原虫FCC-1/HN株的GAPDH基因序列与泰国K1株的GAPDH基因序列一致。     

The development of a recombinant hybrid protein of Plasmodium falciparum and analysis of its antigenicity and protectivity

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用胶体金标记法观察P195蛋白与人红细胞特异性结合区域

寻找恶性疟原虫裂殖子表面主要蛋白Ｐ１９５中的红细胞结合位点，为设计疫革阻断裂殖子红细胞提供实验依据：方法在大肠杆菌中分８段表达Ｐ１９５蛋白，用镍亲和层析柱分离这些蛋白。各段蛋白经复性后用胶体金标记、。标记后的蛋白与人红细胞共孵育，经固定，切片后在电镜下观察。     

Cytokine-induced inhibition of Plasmodium falciparum erythrocytic growth in vitro.

The addition of recombinant cytokines to Plasmodium falciparum in vitro cultures retarded the growth of the parasite with the effect of recombinant IL-2 (rIL-2) > interferon-gamma (IFN-gamma) > tumour necrosis factor-beta (TNF-beta). The process was concentration dependent, being greatest at 30,000 U/ml and required a 72-h period of continuous exposure for maximum effect. Growth inhibition, as determined morphologically and radiometrically, was a consequence of defective schizont maturation rather than inhibition of merozoite invasion. It was cumulative and detectable within one erythrocytic (48 h) growth cycle.     

Subcloning,sequencing and expressing of conserved blocks of P190 gene of Plasmodium falciparum FCC1/HN strain

190-kilodalton glycoprotein (P190) of Plasmodium falciparum,precursor of themajor surface protein of merozoites,is considered a promising candidate for blood stage malarialvaccine.Six primers were designed according to the sequence of MAD20 strain,with a GCclamp and BamH Ⅰ site at the 5'-end of each one,and a GC clamp and Xba Ⅰ site at the 3'-endof each one.The primers were synthesized by phosphoramidite approach (User's Manual ofABI Company) and purified using HPLC.Three fragments in the second,third and fourth con-served regions of P190 gene of Plasrnodium falciparum FCC1/HN strain isolated from theblood of patients in Hainan Province of China were amplified by the polymerase chain reaction(PCR).The amplified fragments were suhcloned into pUC18 vectors and sequenced using thedideoxy chain termination method.All three regions of P190 gene of FCC1/HN strain also werehighly conservative as compared with P190 gene of MAD20 (Papua New Guinea isolate),K1(Thailand isolate),Wellcome (West Africa isolate) and CAMP (Malaysia) strains ofPlasmodium falciparum.The C at position 81 in the second conserved block of P190 gene ofFCC1/HN isolate was substituted by T,which did not change the amino acid determined by thecodon corresponding to the substitution.The genes sequenced were cloned into rpGEX-2T,aglutathione S-transferase gene fusion system for expression.     

中国脑型疟患者恶性疟原虫分离株裂殖子表面蛋白MSP1第16—17区基因的分子克隆及序列分析

目的 :为设计研制安全有效的人脑型疟疫苗提供进一步科学依据。方法 :应用多聚酶链反应 ( PCR)技术对中国 5例脑型疟患者恶性疟原虫云南省勐腊县勐罕 CMH/YN分离株和云南省盈江县农场 CYJ/YN分离株基因组 DNA裂殖子表面蛋白 1( MSP1)第 13— 17区基因进行扩增 ,将扩增产物分别经 Eco RI和 Kpn I双酶切后 ,回收的 MSP1第 16— 17区基因分子定向克隆M13mp18和 M13mp19载体 ,按 Sanger双脱氧链终止法进行 DNA序列测定 ,并与 MAD2 0、K1和Wellcome株原型基因进行同源性分析比较。结果 :发现脑型疟患者恶性疟原虫 CMH/YN和 CYJ/YN分离株 MSP1第 16— 17区基因之间的序列完全相同 ,全长为 918bp,编码 30 6个氨基酸 ,含 12个半胱氨酸组成的 2个表皮生长因子 ( EGF)单体结构域 ;除了在核苷酸第 4 869位缺失 1个碱基和散在分布 5个碱基点突变之外 ,与 MAD2 0、K1和 Wellcome株相应基因之间的核苷酸同源性分别为 98.6%、2 3.3%和 2 2 .8%。结论 :本研究在世界上首次报道脑型疟患者恶性疟原虫分离株MSP1第 16— 17区 DNA序列测定分析结果 ,确证该基因与 MAD2 0株高度同源性 ,并发现在1691— 170 1位氨基酸存在 TCTEEDSGSSR表位。     

恶性疟原虫（海南株）cDNA表达文库的构建及初步鉴定

目的 :构建恶性疟原虫 c DNA表达文库。方法 :采用“一步法”提取红内期恶性疟原虫12 2 4 μg RNA,经 Oligo( d T)纤维素柱纯化得到 35.84 μg poly ( A) m RNA。取 10 μg m RNA反转录得到 1.75μg平端双链 c DNA,与含 Eco RI,Not I,Sal I酶切位点的衔接头连接后 ,经分级分离柱纯化回收到 2 0 0 ng大小主要在 50 0 bp- 7kb左右的 c DNA片段。取 50 ng c DNA与λgt11噬菌体臂连接后体外包装 ,完成建库。并采用 PCR方法初步鉴定该文库。结果 :已构建一个含 10 6个重组子的 c DNA表达文库。结论 :文库容量及插入 c DNA片段的大小适合于进一步研究。     

Topography of epitopes on a polymorphic schizont antigen of Plasmodium falciparum determined by the binding of monoclonal antibodies in a two-site radioimmunoassay

The topographic distribution of common and variant epitopes on two divergent allelic forms of the 185-205K schizont glycoprotein of Plasmodium falciparum were studied by a two-site radioimmunoassay using monoclonal antibodies. Similarities in the conformation of the two molecules were apparent. On both antigens two distinct regions were mapped, each comprising of both strain-common and polymorphic epitopes. Epitopes common to the two PSAs were found to be closely associated with different variable epitopes in tertiary structure. It is suggested that this may contribute to parasite evasion of the host immune response.     

恶性疟原虫多价重组疫苗的研制及其免疫活性的初步鉴定

为了探讨含Ｔ、Ｂ淋巴细胞双重激活表位的重组复合症疾抗原的免疫原性和保护作用，作者设计合成了编码恶性疟原虫红内期３个保护性抗原位点和２个外源性Ｔ细胞激活位点的复合基因ＨＧＦＣ，并构建了多连体复合基因ＨＧＦＣＡＣ。两种复合基因分别与表达载体ｐＷＲ４５０－１重组，并在大肠杆菌中表达出含外源蛋白和β－半乳糖苷酶部分氨基酸的融合蛋白（分子量分别为６５０００和７７０００），表达量为３５％。表达产物可与小鼠及兔抗恶性疟原虫抗体发生特异性免疫反应。用纯化的融合蛋白免疫家兔制备的免疫血清可特异地识别恶性疟原虫抗原，并对疟原虫体外生长有显著抑制作用。抑制程度与免疫血清浓度及作用时间呈正相关，在２０％浓度下作用７２小时，抑制率可达８２％，并引起疟原虫发育不良和死亡。研究结果说明，制备的恶性疟原虫重组复合抗原具有免疫原性和一定的免疫保护作用，可作为恶性疟疫苗候选物。     

伯氏疟原虫K173株对喹哌抗药性的实验研究

用小剂量递增法培育伯氏疟原虫对喹哌的抗药性,起始剂量7 mg/kg×1,每传三代递增3.5 mg/kg,至20代,历时5个多月,培育出对喹哌有110倍以上抗性的虫系。抗喹哌伯氏疟原虫系对羟基喹哌、甲氟喹、青蒿酯、青蒿素都有明显的交叉抗性,对咯萘啶、氯喹和伯喹仅有微弱交叉抗性;对乙胺嘧啶和硝喹显示高敏效应。但该虫系的抗性尚不稳定,停药后连续血传12代,抗性水平由110多倍降至8倍.