用单克隆抗体鉴定恶性疟原虫裂殖子表面抗原

用海南省恶性疟原虫Fcc7801/HN作为抗原,制备的抗恶性疟原虫单克隆抗体C6株具有明显的抑制体外恶性疟原虫生长的作用,并且与恶性疟原虫Fcc-1/HN,Fcc7802/HN,Fcc8703/JS和伯氏疟原虫、食蟹猴疟原虫有较广泛的交叉免疫荧光反应。用免疫电镜观察,此株单克隆抗体能识别恶性疟原虫裂殖子表面抗原,用免疫印迹法测得该抗原分子量为71kDa,此抗原有可能成为疟疾疫苗的候选抗原。     

两株海南省恶性疟原虫gp195的脱氧核糖核酸序列分析

用聚合酶链反应(PCR)法扩增两株海南省恶性疟原虫gp195的第二区,并用dd NTP链终止法测得154个氨基酸序列。实验结果表明:海南省FCC7801/HN的B3克隆及FCCM21/HN两株此区序列完全相同,与巴布亚新几内亚MAD20株很相近,但有10个氨基酸的位点有区别。     

一个恶性疟原虫分离株克隆的抗原性、药敏性分析

恶性疟原虫FCC7801/HN株的不同克隆与抗FCC7801/HN红内期单克隆抗体进行间接荧光抗体试验,表现出显著的反应性差异;疟原虫克隆间对氯喹的敏感性亦有明显不同。这提示了同一恶性疟原虫分离株内的不同克隆生物学特性的不均一性。     

3种恶性疟原虫红内期抗原基因的测序和序列分析

目的　测定我国恶性疟原虫海南株 (FCC1/ HN)谷氨酸富集蛋白 (GARP)、丝氨酸重复抗原 (SERA)和裂殖子表面蛋白 1(MSA1)基因序列 ,并进行序列分析。　方法　采用 PCR技术从恶性疟原虫 FCC1/ HN株基因组 DNA中扩增 GARP、SERA和 MSA1基因片段 ,分别插入到测序载体上进行测序。应用 DNAstar软件辅助分析 3种抗原基因的结构及 3种抗原在不同恶性疟原虫株间的分化情况。　结果　恶性疟原虫 FCC1/ HN株 GARP基因全长 2 2 6 3bp,编码6 82个氨基酸残基 ,谷氨酸占 2 3.6 1% ,包含 5个典型的氨基酸重复序列 ;SERA基因全长 344 8bp,编码 995个氨基酸残基 ,丝氨酸含量为 10 .6 5 % ,包含 1个连续 32个丝氨酸 (S)残基的序列 ;MSA1基因全长 5 0 85 bp,编码 16 94个氨基酸残基 ,MSA1的氨基酸序列符合 MAD2 0型特征。恶性疟原虫 FCC1/ HN株与 3D7、FC2 7株 GARP的序列差异主要集中于 C-末端 ;FCC1/ HN株与 FCR3、3D7、FCBR、Hondulas- 1株 SERA的序列差异主要集中于 N-端。FCC1/ HN株与MAD2 0、3D7、HN1、HN2、FC2 7、RO- 71、RO- 33、CAMP和 Palo- alto株 MSA1的同源性高 ,K1和 WEL L COME株 MSA1的同源性高 ,各分离株 MSA1的序列差异主要处于第 2至 16分区。　结论　了解了恶性疟原虫 FCC1/ HN株 GARP、SERA和 MSA1的     

3种恶性疟原虫红内期抗原基因的测序和序列分析

目的 测定我国恶性疟原虫海南株（FCC1／HN）谷氨酸富集蛋白（GARP），丝氨酸重复抗原（SERA）和裂殖子表面蛋白1（MSA1）基因序列，并进行序列分析。方法：采用PCR技术从恶性疟原虫FCC1／HN株基因组DNA中扩增GARP，SERA和MSA1基因片段，分别插入到测序载体上进行测序。应用DNAstar软件辅助分析3种抗原基因的结构及3种抗原在不同恶性疟原虫株间的分化情况。结果 恶性疟原虫FCC1／HN株GARP基因全长2263bp，编码682个氨基酸残茯，谷氨酸占23．61％，包含5个典型的氨基酸重复序列；SERA基因全长3448bp，编码995个氨基酸残基，丝氨酸含量为10．65％，包含1个连续32个丝氨酸（S）残基的序列；MSA1基因全长5085bp，编码1694个氨基酸残基，MSWA1的氨基酸序列符合MAD20特征。恶性疟原虫FCC1／HN株与3D7，FC27株GWARP的序列差异主要集中于C－末端；FCC1／HN株与FCR3，3D7，FCBR，Hondulas-1株SERA的序列差异主要集中于N－端，FCC1／HN株与MAD2，3D7，HN1，HN2，FC27，RO－71RO－33，CAMP和Palo-alto株MSA1的同源性高，K1和WELLCOME株MSA1的同源性高，各分离株MSA1的序列差异主要处于第2至16分区。结论 了解了恶性疟原虫FCC1／HN株GARP，SERA和MSA1的初级结构及其编码基因结构。恶性疟原虫FCC1／HN株与其它分离株GARP和SERA的氨基酸序列差异集中于特定区段，FCC1／HN株MSA1不同分区的氨基酸序列与其它分离株MSA1的对应序列存在不同程度的差异。     

恶性疟原虫传播阻断抗原Pfs25和Pfs48/45基因编码序列的体外扩增

目的：体外扩增编码恶性疟原虫传播阻断抗原Pfs和Pfs48／45的基因序列,为进一步对其进行克隆和体外高效表达创造条件。方法：特定寡核苷酸引物的设计、合成与纯化;恶性疟原虫FCC1／HN株体外培养;利用碱裂解法从培养的恶性疟原虫FCC1／HN株提取染色体DNA;PCR扩增和琼脂糖凝胶电泳分析。结果：从恶性疟原虫FCC1／HN株基因组DNA中特异扩增出编码Pfs25和Pfs48／45基因序列,其片段大小分别为657bp和1,359bp。而用间日疟原虫基因组DNA为模板作对照,无扩增条带出现。结论：体外扩增编码恶性疟原虫传播阻断抗原Pfs25和Pfs48／45基因序列与预期长度相符合,从而,为该基因的克隆、测序和表达奠定基础。     

恶性疟原虫FCC_(102)/JS株的建立

1984年9月于江苏省盱眙县境分离一恶性疟原虫虫株,暂定名为FCC-102/JS株连续培养观察52天生长良好。其96小时培养原虫平均增殖倍数为3.83±1.13倍,较海南岛株低(FCC-1/HN株为10.03±0.88,FCC-4/HN株为9.85±0.38)。该株配子体多见,平均占11.65±3.11％。用兔血清代替人血清不易生长。体外微量药效测定氯喹对FCC-102/JS株的半数有效浓度为42.03(28.51-61.95)nM,提示该株为氯喹敏感株,可作为抗原分析、研制疫苗及微量药效测定用的原虫模型。     

恶性疟原虫海南株AMA-1、Pfs230基因的序列分析

目的　测定恶性疟原虫海南 (FCC1/HN)株裂殖子顶端膜抗原 1(AMA - 1)基因和Pfs2 30基因序列 ,并分别进行序列分析。方法　根据AMA - 1基因已知序列合成一对引物 ,用PCR技术从恶性疟原虫FCC1/HN株基因组DNA中扩增AMA - 1基因 ,构建真核表达重组质粒 pcDNA3 -AMA - 1。根据Pfs2 30基因已知序列合成七对引物 ,分 7段从FCC1/HN株基因组DNA中扩增Pfs2 30基因 ,并分别将扩增片段插入pMD - 18T测序载体。用双脱氧链末端终止法测定克隆的AMA -1、Pfs2 30基因序列 ,应用DNAstar软件辅助进行序列分析和同源性比较。结果　PCR扩增得到恶性疟原虫FCC1/HN株AMA - 1和Pfs2 30基因片段。恶性疟原虫FCC1/HN株AMA - 1基因全长 186 9bp ,无内含子 ,编码 6 2 2个氨基酸残基 ,不存在氨基酸重复序列 ,相对分子量约 72 0 4 5kDa ;Pfs2 30基因全长 94 35bp ,无内含子 ,编码 314 4个氨基酸残基 ,分子量为36 4 36kDa。恶性疟原虫FCC1/HN株与FC2 7、7G8、CAMP、FCR3、Thai -Tn、3D7、FVO、KF1916、CMP1、HB3、K1和V1株AMA - 1的同源性在 94 9%以上 ,各株间有 5 3个位置相同的氨基酸残基替代位点 ,并且发生替代的氨基酸残基具二态性。FCC1/HN株分别比 3D7、7G8株Pfs2 30抗原多 9、10个氨基酸残基 ,三个分离株有 2 8个氨基酸替换     

用聚合酶链反应技术鉴别恶性疟原虫不同地理株的初步研究

目的　阐明 Fcc1/ HN株与云南株间的不同生物学特性。　方法　用 M2 6 - 32 作探针 ,筛选恶性疟原虫 c DNA基因表达文库 ,根据所获得的靶抗原决定簇表位的基因序列设计引物 ,分别进行 PCR扩增 ;地高辛酶促生物标记 Fcc1- HN株 DNA的 PCR扩增产物 ,分别与 Fcc1/ HN株 DNA、云南株 DNA和阳性克隆 5 11的扩增产物杂交。　结果　 PCR扩增后 Fcc1/ HN株 DNA在约 5 0 0 bp和 4 5 0 bp处有 2条特异性条带 ;云南株 DNA在约 5 0 0 bp处有 1条较淡的条带和 130 0bp处一较亮的特异性条带 ;阳性克隆 5 11仅在约 5 0 0 bp处有 1条特异性条带。标记探针能与克隆 DNA、恶性疟原虫Fcc1/ HN株和云南株的 PCR扩增产物杂交。　结论　恶性疟原虫 Fcc1/ HN株与云南株在基因组 DNA结构上可能存在差异。     

用聚合酶链反应技术鉴别恶性疟原虫不同地理株的初步研究

目的 阐明Fccl/HN株与云南株间的不同生物学特性。方法 用M26-32作探针，筛选恶性疟原虫cDNA基因表达文库，根据所获得的靶抗原决定簇表位的基因序列设计引物，分别进行PCR扩增；地高辛酶促生物标记Fccl-HN株DNA的PCR扩增产物，分别与Fccl/HN株DNA，云南株DNA和阳性克隆511的扩增产物杂交。结果 PCR扩增后Fccl/HN株DNA在约500bp和450bp处有2条特异性条带；云南株DNA在约500bp处有1条较淡的条带和1300bp处一较亮的特异性条带，阳性克隆511仅在约500bp处有1条特异性条带，标记探针能与克隆DNA，恶性疟原虫Fccl/HN株和云南株的PCR扩增产物杂交。结论 恶性疟原虫Fccl/HN株与云南株在基因组DNA结构上可能存在差异。     

Antibodies to the major merozoite surface coat protein of Plasmodium falciparum (gp195) in a human population living in a malaria-endemic area of the Philippines.

The seroprevalence of naturally acquired antibodies against Plasmodium falciparum merozoite surface protein gp195 was assessed in 726 individuals living in the Napsan region of Palawan in The Philippines. Antibodies against gp195 were detected using parasite-derived antigens in an enzyme-linked immunosorbent assay. The lowest seroprevalence of anti-gp195 antibodies (45%) was found in the 0-4-year-old age group. By 10-19 years of age, the seroprevalence of anti-gp195 antibodies had leveled off at approximately 90%. Anti-gp195 antibody titers were determined for 59 randomly selected individuals using parasite-derived gp195 and two yeast recombinant polypeptides corresponding to the N-terminal (195A) and C-terminal (p42) processing fragments of gp195. For each antigen, the lowest antibody titers were found in the 0-4-year-old age group. The 5-9-year-old age group had anti-gp195 antibody titers comparable with the older age groups. Immunoblotting experiments with parasite-derived gp195 revealed that all serum samples tested had detectable antibodies to the 195-kD gp195 precursor molecule and the 83-kD N-terminal processing fragment. Individuals with anti-gp195 titers greater than 1:400 had antibodies against both the N-terminal and C-terminal processing fragments of gp195. These results suggest that the gp195 C-terminal region may be less immunogenic than the N-terminal region when presented on the parasite surface during natural malaria infections.     

Heterogeneity and immunogenicity of the Trichinella TSL-1 antigen gp53

This study investigates the heterogeneity and immunogenicity of the Trichinella TSL-1 antigen gp53. Western blotting analysis of several Trichinella isolates with the gp53-specific monoclonal antibodies (mAbs) US5 and US9, produced in Btkxid mice, revealed that gp53 from the species T. britovi, T. murrelli and genotype T8 had higher MW (60 kDa) than gp53 from T. spiralis, T. nelsoni and genotype T6 (53 kDa) and from T. nativa (55 kDa). mAb US5 reacted only with gp53 from T. spiralis. Experiments including immunoassays of gp53 binding by sera from T. spiralis-infected mice, in the presence of different potential inhibitors (recombinant gp53, US5, T. britovi-crude larval extract (CLE), and CLE N- and O-glycans), indicate (i) that gp53 from T. spiralis bears specific epitopes that induce antibody formation during infection; (ii) that the protein epitopes of gp53 are much more important (76 or 68% of total antibody reactivity in BALB/c and Swiss CD-1 mice, respectively) than the corresponding glycan epitopes including tyvelose (11 or 32% of total reactivity) for the induction of anti-gp53 circulating antibodies; and (iii) that the species-specific epitopes present on gp53 are differentially recognized in different mouse strains. Whereas in BALB/c mice US5- and non-US5-recognized species-specific epitopes on gp53 bind about 84% of circulating antibodies on day 80 post-infection, this percentage was only 38% in Swiss CD-1 mice. These data on the antigenicity of gp53 contrast with data for Trichinella CLE antigens, in that most circulating antibodies reactive with CLE antigens recognized tyvelose-containing epitopes (57% and 58% of circulating antibodies in BALB/c and Swiss CD-1 mice, respectively). Together these results demonstrate that gp53 is recognized during infection but is antigenically different from other Trichinella TSL-1 antigens.     

抗隐孢子虫单克隆抗体研制及其特异性的鉴定

目的：制备抗隐孢子虫单克隆抗体（McAb）并对其特异性进行鉴定。方法：用纯化的人源微小隐孢子虫卵囊免疫BALB／c小鼠，杂交瘤技术制备McAb，间接免疫荧光（IFA）和免疫印迹试验分析其特性。结果：制备出Z4C8、Z2B6、Z3D7和Z3D2四株能稳定分泌抗隐孢子虫McAb的杂交瘤细胞株。经鉴定，Z4C8和Z3D7为IgM ，Z3D2和Z2B6为IgG1，轻链均为κ链，与多种肠道病原体及肺孢子虫无交叉反应。除Z2B6在间接免疫荧光试验中识别卵囊壁外，其余均识别隐孢子虫子孢子（CSP）。免疫印迹定位表明，四株McAb分别识别42条CSP抗原中的20．5kDa、60．5kDa、33kDa和95kDa4个条带，其中Z4C8和Z3D7均识别20．5kDa主要抗原带。结论：这四株McAb在识别CSP抗原表位上具有不同的特性，但对隐孢子虫抗原均呈高度特异性反应。     

Coexistence of GP195 alleles of Plasmodium falciparum in a small endemic area

Dimorphic variations in the genotype of the precursor to Plasmodium falciparum major merozoite surface antigens or gp195, among wild isolates in a small malaria parasite population were examined using Southern blot hybridization techniques. Hybridization, with DNA fragment probes and oligonucleotide probes derived from variable blocks of known gp195 alleles against 18 wild isolates from Mae Sod district in Thailand, revealed the existence of seven gp195 alleles, two of which were newly identified in this study. In four out of 17 patients, two different alleles coexisted in the circulation. It was furthermore noted that the seven alleles did not occur at the same frequency, but rather several alleles predominated in the population of P. falciparum in this small malaria field.     

旋毛虫部分抗原表位的识别与分析

[目的 ]筛选旋毛虫肌幼虫可溶性抗原中具有免疫显性的表位。 [方法 ]采用杂交瘤技术 ,获得 15株特异性单克隆抗体 ,随后用酶联免疫吸附试验 (ELISA)、免疫印迹法 (Westernblotting)和间接免疫荧光试验(IFA)对部分免疫显性抗原进行分析。 [结果 ]Westernblotting试验显示 ,6株单抗与旋毛虫肌幼虫可溶性抗原反应显示有特异条带 ,分子量为 40～ 70kDa ;而多抗血清则可识别 2 0～ 2 0 0kDa之间 10条条带。IFA可观察到 ,6株单抗中有 4株单抗的靶抗原定位在旋毛虫肌幼虫表皮层上 ,另 2株定位于杆状体 (stichosome)及表皮层。 [结论 ]识别与分析部分旋毛虫肌幼虫可溶性抗原中具有免疫显性的表位 ,为纯化旋毛虫的抗原及疫苗靶抗原的研制提供了有价值的实验依据。     

Generalized immunological recognition of the major merozoite surface antigen (gp195) of Plasmodium falciparum.

The antibody response to the Plasmodium falciparum major merozoite surface antigen (gp195) of congenic mouse strains differing in H-2 haplotype has been examined. All seven strains of mice were capable of producing gp195-specific antibodies. Generalized immune recognition of gp195 by mice of diverse H-2 haplotypes distinguished gp195 from the P. falciparum circumsporozoite protein and the 230-kDa and 48/45-kDa gamete surface antigens. However, the H-2 genetic locus appeared to influence the specificity of gp195-specific antibodies. Immunoblot patterns of mouse sera with parasite antigens revealed a complex pattern of reactivity with terminal and intermediate processing fragments of gp195. The majority of immunoblot bands observed were similar for all of the mouse strains; however, there were several strains that additionally recognized a few unique fragments or displayed more intense reactivities with specific processing fragments. These results suggest that while individuals of diverse major histocompatibility complex makeup are capable of recognizing the gp195 antigen, the recognition of specific gp195 B-cell and T-cell epitopes may be under control of the major histocompatibility complex.     

Antigenic diversity and size diversity of P. falciparum antigens in isolates from Gambian patients. II. The schizont surface glycoprotein of molecular weight ˜ 200 000

A panel of monoclonal antibodies has been shown previously to identify both serologically diverse and serologically conserved epitopes on a major polymorphic surface protein of P. falciparum schizonts from culture-adapted isolates. The molecular nature of the antigen recognized by eight of these monoclonal antibodies was studied with three isolates analyzed directly from patients in The Gambia. Malarial (glyco) proteins were labelled by biosynthetic uptake of 3H-glucosamine or 3H-leucine during culture of ring-stage parasites from infected blood to the late-trophozoite/early-schizont stage (26-30 h). Those monoclonal antibodies which reacted positively with an isolate by indirect immunofluorescence also immunoprecipitated a single 3H-leucine or 3H-glucosamine labelled antigen of mol. wt approximately 200 000 from Triton X-100 extracts of the same isolate. Monoclonal antibodies which did not react by indirect immunofluorescence failed to immunoprecipitate this antigen. Although each of the three isolates studied in detail was very similar serologically with the panel of monoclonal antibodies specific for this mol. wt approximately 200 000 antigen, this protein could be distinguished with each isolate on the basis of its apparent size on SDS-polyacrylamide gel electrophoresis. The specifically immunoprecipitated antigen had a mol. wt of 204 000, 197 000 or 202 000, depending on the isolate. Size diversity of this malarial glycoprotein was also detected with seven other Gambian P. falciparum isolates. We conclude that natural isolates of P. falciparum express a major 3H-glucosamine labelled glycoprotein of mol. wt Mr approximately 200 000 which exhibits size diversity and expresses antigenically conserved as well as diverse epitopes as defined by the panel of monoclonal antibodies.     

恶性疟原虫乳酸脱氢酶单克隆抗体的制备及其鉴定

[目的 ]制备抗恶性疟原虫乳酸脱氢酶 (LDHp)单克隆抗体 (McAb) ,并对其特异性进行鉴定。[方法 ]用纯化的LDHp重组抗原免疫BALB/c小鼠 ,采用杂交瘤技术制备McAb ,筛选分泌高滴度McAb的杂交瘤细胞株 ,测定其免疫球蛋白亚类及其效价 ,ELISA、Westernblot试验分析其特异性。 [结果 ]筛选出 2A5和1H10两株能稳定分泌抗LDHpMcAb的杂交瘤细胞株 ,两株单抗均为IgG2b,2A5和 1H10培养上清的ELISA效价分别为 1∶5 12和 1∶2 5 6 ,腹水效价分别为 1∶2 5 6 0 0和 1∶12 80 0 ,两株单抗与间日疟原虫、红细胞、弓形虫、日本血吸虫等抗原均不发生交叉反应 ,能识别恶性疟原虫 33kDa的虫源蛋白。 [结论 ]制备的抗LDHp杂交瘤细胞株能分泌高滴度和高特异性的单抗     

抗恶性疟原虫复合重组抗原单克隆抗体的制备、鉴定及其体外抑制试验

目的制备抗恶性疟原虫单克隆抗体,为疟疾诊断及疟疾疫苗等方面的研究提供良好的材料。方法以恶性疟原虫复合重组融合蛋白为免疫原,经细胞融合及ＥＬＩＳＡ方法筛选获得阳性杂交瘤细胞。对其中３株２Ｈ１２、３Ｄ５、４Ｅ５进行了染色体核型分析,对其分泌的单克隆抗体作ＳＤＳ－ＰＡＧＥ、Ｗｅｓｔｅｒｎｂｌｏｔ及Ｄｏｔ－ＥＬＩＳＡ鉴定,并初步观察了３株单抗对恶性疟原虫（海南分离株）的体外抑制作用。结果两次细胞融合共获得８株阳性克隆,其中３株即２Ｈ１２、３Ｄ５、４Ｅ５的ＯＤ值超过阳性对照,传至２０代以上经ＥＬＩＳＡ检测仍呈强阳性反应,将其腹腔接种给ＢＡＬＢ／ｃ小鼠获得血性腹水,抗体滴度为１∶１２８００。Ｗｅｓｔｅｒｎｂｌｏｔ及Ｄｏｔ－ＥＬＩＳＡ分析显示３株单抗均与相应蛋白发生特异性反应。抑制试验结果表明：３株单抗对恶性疟原虫的体外生长和发育均有一定的抑制作用,抑制率分别为４９％±３％、７６％±６％、４１％±２％。结论已获得稳定分泌抗恶性疟原虫复合重组抗原单克隆抗体的杂交瘤细胞株。