钩端螺旋体澳洲群体特异性McAb的建立,鉴定及群特异性...

Spleen cells of BALB/c mice immunized with whole Leptospira interrogans serogroup Australis serovar australis strain 620 were fused with myeloma cells line SP2/0. Specificities of four McAbs determined by MAT. 2E1 McAb (IgG3) reacted with 11 serovars, of the Australis serogroup, but did not react with 22 representative serovars of L. interrogans in 20 serogroups, L. biflexa strain patoc I and Leptonema illini strain 3055. 2E1 McAb showed serogroup specificity for Australis by agglutination and the other 3 McAbs showed partial serogroup specificity. We compared the outer envelope (OE) protein profiles of serovar australis strain 620 with those of two pathogenic L. interrogans serovar lai strain 601 and serovar hebdomadis strain 156 by SDS-PAGE. 63kd protein profile was only found in the OE of strain 620, and the quantity of 42kd protein of strain 620 was greater than that of strain 601 and 156. The immunoblotting revealed that 2E1 McAb reacted with a 34kd band in the OE preparation of serovar australis strain 620, but did not react with that of other two L. interrogans. 2E1 McAb also did not react with OE of non-pathogenic leptospires. It was suggested that 34kd protein might contain the antigenic determinants which were shared by leptospires of Australis serogroup.     

钩端螺旋体七日热群部分群特异McAb的建立与鉴定

Hebdomadis is one of the major serogroups found in China. In Sichuan, this serogroup appears to have a close relationship with local outbreak of leptospirosis. BALB/c mice were immunized intrasplenically with outer envelope of serogroup Hendomadis serovar hebdomadis strain 245. Spleen cells were fused with SP2/0 myeloma cells, two monoclonal antibodies Af2 and Bb2 were produced by hybridoma technique. McAb Af2 and McAb Bb2 were identified to be IgG1 and IgG3 by immunodiffusion respectively. Specificities of these two McAbs were determined by MAT; both reacted to 8 serovars (hebdomadis, nona, kambale, kremastos, worsfoldi, jules, maruborincana) of Hebdomadis serogroup. The agglutination titres of McAb Af2 and McAb Bb2 were 1:640-1:2,500,000 and 1:320-1:2,500,000, respectively. The two McAbs did not agglutinate with serovar kabura of Hebdomadis serogroup, they did not agglutinate with 11 serovars of Sejroe serogroup, 4 serovars of Mini serogroup, 18 representive serovars of L. interrogans in 18 serogroups, L. biflexa strain Patoc I and Leptonema illini. So it was found that McAb Af2 and McAb Bb2 showed partial serogroup specificity for Hebdomadis by agglutination.     

针对问号钩体赖型外膜的抗原分析

作者采用SDS-聚丙烯酰胺凝胶电泳和免疫印迹技术,对黄疸出血群赖型017株和601株、七日热群七日热型156株、澳洲群澳洲型620株以及塞马伦群帕托克型Patoc Ⅰ株等5株钩体外膜进行分析。检测到具有免疫保护作用和抑制钩体粘附作用的单克隆抗体E_4B_7D_5能特异地识别赖型017株和601株钩体外膜的34.5kd和39.5kd两条蛋白带,而同其余3株钩体外膜蛋白无反应。由此提示该两条蛋白带可能为钩体外膜保护性抗原。     

钩端螺旋体澳洲群群特异性McAb的建立、鉴定及群特异性抗原检测

作者成功地获得4株分泌抗澳洲群钩瑞螺旋体的单克隆抗体(McAb)杂交瘤。其中2E_1株能与所选澳洲群的11个型的钩体都发生凝集反应,而不与澳洲群外的20群22个型的钩体、非致病性Patot Ⅰ株钩体和伊利尼细螺旋体3055株发生凝集反应。由此表明,2E_1 McAb具有澳洲群钩体的群特异性。用SDS-PAGE、免疫印迹法对澳洲型620株、赖型601株、七日热型156株、Patoc Ⅰ株及3055株外膜蛋白中McAb识别的抗原成分进行检测,结果2E_1 McAb能特异地识别澳洲型620株34kd外膜蛋白区带。其余3株McAb具有澳洲群钩体部分群特异性。     

钩端螺旋体七日热群部分群特异McAb的建立与鉴定

经脾内注射七日热群七日热型钩体外膜抗原免疫BALB/c小鼠,取脾内细胞与SP2/0骨髓瘤细胞融合,筛选出两株抗七日热群钩体的McAb.显凝试验(MAT)表明,Af_2和Bb_2两株McAb均能与选用的七日热群9型钩体中的8型钩体发生凝集反应,但不与卡布那型钩体凝集,而选用的其他20群33型问号钩体,双曲钩体Patoc Ⅰ株和细螺旋体伊尼利型3055株均为MAT阴性,从而证明Af_2和Bb_2两株McAb具有七日热群部分群特异性.     

抗黄疸出血群70091株钩端螺旋体外膜抗原单克隆抗体的研制

本实验建立了一株分泌抗黄疸出血群钩端螺旋体外膜抗原的单克隆杂交瘤细胞株ZMA_3。ZMA_3单克隆抗体具有较高的群特异性,经鉴定该抗体属IgG2a亚类。该杂交瘤细胞株经体外持续培养7个月余,分泌抗体性能稳定。     

Homology study of leptospires by molecular hybridization]

Nick translation and random primer labelling method were applied to prepare three genomic DNA probes from Leptospira interrogans strain 017, Leptospira biflexa strain Patoc I and Leptonema illini strain 3055, and then hybridized with DNA of 17 strains leptospires from different genus, species, serogroup and serovar. The results showed no homology between Leptospira and Leptonema, and only a low degree of homology between L. interrogans and L. biflexa but it showed a high degree of homology among L. interrogans. The study also proved the possibility to establish a DNA probe prepared from a single leptospira strain to detect different serovars.     

Observation of monoclonal antibody E4B7D5 inhibitory effect on leptospiral adherence using scanning electron microscope]

BALB/c mice were immunized intraperitoneally with outer envelopes of serogroup icterohaemorrhagiae lai serovar strain 017 leptospires. Monoclonal antibody (McAb) E4B7D5 against outer envelopes (IgG1, agglutinating titre 1:25,600) was produced by hybridoma technique. Passive immunoprotection experiments have demonstrated the immunoprotection of McAb E4B7D5 against strain 017 leptospires. Effect of McAb E4B7D5 on leptospiral adherence to the surface of normal human pulmonary embryonic fibroblasts was observed by using scanning electron microscope. The results indicated that the leptospiral adherence noted in various agglutinating titre McAb E4B7D5 groups was less frequent than that in the three control groups. It was concluded that the inhibitory effect of McAb E4B7D5 on leptospiral adherence may play a role in the immunoprotection.     

Monoclonal antibodies to Leptospira interrogans serovar pomona

Three monoclonal antibodies produced against Leptospira interrogans serovar pomona have been studied for their diagnostic usefulness. All three monoclonals reacted strongly in the enzyme-linked immunosorbent assay and indirect fluorescent antibody test with serovar pomona and did not react with serovars grippotyphosa, canicola, icterohaemorrhagiae and hardjo.     

聚合酶链反应检测致病性钩端螺旋体微量DNA的研究

Leptospirosis is a severe zoonosis in the world. The methods for detecting leptospira are not sensitive and specific so far. The problems in early diagnosis and epidemiological identification of Leptospirosis remain unsolved. Two recombinant DNA fragments of serogroup Icterohaemorrhagiae, Leptospira were selected by repeated molecular cloning and screening in this study firstly. One of them can hybridize with the DNA of various serogroups of Leptospira interrogans; the other can only hybridize with the DNA of serogroup Icterohaemorrhagiae. After the nucleotides sequence analysis, from these 2 recombinant DNA fragments, 2 pairs of polymerase chain reaction (PCR) oligonucleotide primers were synthesized, named primer B 1, 2 and primer B 3, 4 PCRs were carried out with these 2 primers for detecting the microquantity (0.1 ng) of various serovars, serogroup of leptospires. All the DNA of Leptospira interrogans can be amplified by primer B 1, 2, and only the DNA of serogroup icterohaemorrhagiae, Leptospira reacted specially with primer B 3, 4. The DNA of non-pathogenetic Leptospira and some other microbes, however, had no amplification at all. This study is first reported at home and abroad. The results demonstrate that PCR is a very sensitive and specific technique of DNA amplification, which can be used as a powerful tool in the early diagnosis and epidemiological identification of leptospirosis.