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1.
采用痢疾菌Ipa^+Oag^-,Ipa^-Oag^+及Ipa^+Oag^+等三种不同的菌株分别进行了毒力及毒力相关表型实验。结果发现,Ipa^+OaG^-株S1R101/pHS4108与Ipa^+Oag^+株BS169/pHS4108都有侵入HelA细胞的能力,而Ipa^-Oag^+株T32则无侵入HeLa细胞的能力,只表达多肽a、c、d的菌株S1R102/pJM56亦不能侵入HeLa细胞。从而证  相似文献   

2.
直接用转化方法将质粒pHS4108转入宋内氏Ⅱ相菌S1R(Ipa^-,Oag^-),构建了菌株S1R101/pHS4108。该菌株能表达侵袭性外膜多肽a,b,c,d,无O抗原。本实验又将质粒pHS4108中的12.5kb SalI片段克隆到质粒pBR322上,构建质粒pJM56,并把它转入S1R株内所得的重组菌S1R102/pJM56能表达多肽a,c,d,但不表达多肽b。  相似文献   

3.
直接用转化方法将质粒pHS4108转入宋内氏Ⅱ相菌S1R(lpa-,Oag-),构建了菌株S1R101/pHS4108。该菌株能表达侵袭性外膜多肽a,b,c,d,无O抗原。本实验又将质粒pHS4108中的12.5kbSalⅠ片段克隆到质粒pBR322上,构建质粒pJM56,并把它转入S1R株内所得的重组菌S1R102/pJM56能表达多肽a,c,d,但不表达多肽b。  相似文献   

4.
目的 FSM-2177和FS-5416是两株具有不同生物表型的福氏、宋内氏双价痢疾菌苗株,FSM-2117无侵袭表型,无溶血活性,不表达侵袭蛋白抗原(Ipa^-),FS-5416则为Ipa^+,本实验是为了观测两株菌苗(Ipa^-,Ipa^+)免疫后引起的肠粘膜相关淋巴组织(GALT)中的细胞免疫反应,以探明痢疾菌苗在肠粘膜的免疫保护机制。方法 以BALB/c小鼠随机分成两组,每组25只,灌胃免疫  相似文献   

5.
通过Plkc噬菌体将Tn10插入灭活的aroD基因片段导入双价有毒痢疾菌FS-15中,构建了该株的芳香族氨基酸营养缺陷减毒株,并通过Bochner培养基去除Tn10所携带的四环素抗性,经原位杂交从中检测到aroD基因缺失株FS-5441。该株稳定表达福氏及宋内氏双价O抗原,Western-blot显示该株表达Ipa蛋白,具有穿入HeLa细胞的能力,穿入率为19%。营养缺陷表型的回复突变率小于10 ̄(-11)。小白鼠毒力试验证明安全无毒,免疫小白鼠后对福氏及宋内氏毒株的攻击具有保护活性。  相似文献   

6.
嗜酸性粒细胞可作为抗原呈递细胞   总被引:18,自引:2,他引:16  
目的探讨HLA-DR+嗜酸性粒细胞(EOS)在体外培养条件下作为抗原呈递细胞(APC)将破伤风类毒素抗原(TT)呈递给T淋巴细胞的能力。方法新分离的EOS经人重组粒细胞-巨噬细胞集落刺激因子刺激24小时,以诱导HLA-DR的表达,然后将其暴露于不同浓度的TT,检测HLA-DR+EOS对自身T细胞增殖反应的影响,以评价EOS呈递抗原的能力。结果HLA-DR+EOS于TT存在时可以明显促进T细胞的增殖反应,并与TT的浓度呈剂量相关性。而抗HLA-DR单克隆抗体则可以明显地抑制EOS的抗原呈递过程。结论人EOS可以摄入和处理抗原并能将其传递给自身T细胞,而EOS呈递抗原的过程具有明显的HLA-DR依赖性。  相似文献   

7.
双价痢疾菌苗株免疫小鼠后GALT中ASC的观测   总被引:3,自引:0,他引:3  
石辛甫  高杰英 《免疫学杂志》1998,14(4):231-232,237
为了观测两株菌苗FSM-2117(Ipa-)、FS-5416(Ipa+)免疫后所引起的肠粘膜相关淋巴组织(GALT)中的免疫反应,以小鼠灌胃免疫为模型,应用BA-ELISPOT法检测了GALT中诱导部位派伊尔小结(PP)、肠系膜淋巴结(MLN)和抗原特异性抗体分泌细胞(ASC),发现两菌苗株免疫小鼠后,PP结、MLN中福氏、宋内氏抗原SIgA、IgG抗体分泌细胞明显增加,尤以SIgA-ASC为甚。株间差别无统计学意义。两株菌苗与对照组相比,都具有显著性差别  相似文献   

8.
采用基因工程技术,将编码恶性疟原虫有性期特异抗原Pfs8/45的基因克隆到真核表达质粒pcD-NA3,并进行DNA序列测定,再通过磷酸钙—DNA共沉淀转化法将重组质粒pcDNA3-pFS48/45导入HeLa细胞,建立稳定分泌Pfs48/45蛋白的阳性克隆株。结果显示,我国海南FCC1/HN株Pfs48/45抗原基因序列与NF54株者高度同源,提示该基因在不同虫株间高度保守,是研制疟疾疫苗的理想靶抗原;在HeLa细胞中表达的Pfs48/45蛋白分子量约为46/43.5kDa双联体蛋白,其表达量占细胞培养上清蛋白总量的18.27%。经WesternBlot分析显示,表在蛋白能被配子体免疫鼠血清特异性识别,提示表达的重组蛋白Pfs48/45具有免疫活性。真核表达系统pcDNA3/Pfs48/45/HeLa的建立为进一步研究重组Pfs48/45抗原的免疫原性和保护性奠定基础。  相似文献   

9.
用多肽固相合成仪合成人癌基因产物p185HER-2(即p185)胞内区的肽段,以之与沙门氏裸菌偶联制成免疫原,经脾内、腹腔、静脉途径免疫Balb/c小鼠,获得具有高抗体活性的脾细胞,后者与SP2/0融合,筛选出5株杂交瘤细胞系并对其分泌的单克隆抗体(McAb)特性进行了初步分析,ELISA检测腹水效价为10-4~10-6,用多肽和沙门氏裸菌分别进行中和试验,多肽抑制率在50%以上,而沙门氏裸菌则不能中和抗体反应。测定其中两株McAb亲和常数(Ka)分别为2.5×107M-1,5.0×108M-1。表位分析结果表明这两株McAb针对同一抗原表位  相似文献   

10.
霍乱弧菌O139某些生物学特性及毒力基因检测   总被引:6,自引:1,他引:5  
O139霍乱弧菌是1992年发现的新型霍乱弧菌,其毒力强,危害严重。对中国、印度、孟加拉国分离的23株O139菌株的部分生物学特征检查表明:对弧菌抑制剂O/129均具有抗性、溶原菌、山梨醇慢发酵、非溶血性。核酸分子杂交显示,所有被检O139菌株都具有主要的霍乱弧菌毒素基因:ctx,zot,ace和RS1序列。PCR检测ctx基因与O1群流行珠具有相同的扩增产物,tcpA基因扩增表现为与埃尔托型霍乱弧菌相似的扩增产物。兔肠段结扎测毒表明,O139霍乱弧菌为强毒株。因此O139菌与O1群霍乱弧菌流行株具有共同的毒力特征。  相似文献   

11.
Virulent strains of Shigella flexneri invade HeLa cells with high efficiency. This crucial step in the pathogenic process is encoded by a 140-megadalton plasmid which induces phagocytosis of the bacteria by host cells. In this report we used pWR100, the virulence plasmid of S. flexneri serotype 5, and pHS4108, a 32-megadalton subclone of pWR100, to demonstrate that the plasmid is also responsible for rapid intracellular growth of the bacteria. The ability to replicate intracellularly was not correlated with induction of Shiga toxin. However, plasmid-mediated intracellular multiplication was strongly correlated with the ability of the bacteria to rapidly and efficiently lyse the phagocytic vacuole and replicate freely in the cytoplasm. Temperature-regulated plasmid-mediated contact hemolytic activity strongly correlated with both phagosomal membrane lysis and efficient intracellular multiplication. We propose this virulence plasmid-associated hemolysin to be an important factor in the invasion and proliferation of Shigella spp. in mammalian cells.  相似文献   

12.
Shigella flexneri requires the outer membrane protein IcsA(VirG) and lipopolysaccharide (LPS) for efficient actin-based motility (ABM) within mammalian cells which is essential for virulence. Wild type strains of S. flexneri 2a such as 2457T have smooth LPS whose O antigen (Oag) chains have two modal lengths and IcsA predominantly located at one pole on their cell surface. In contrast, rough LPS mutants lack Oag chains, have IcsA on lateral and polar regions of the cell surface, and are defective for ABM. In this study we directly compared the phenotype of a S. flexneri producing non-IcsP/SopA cleavable IcsA (IcsA*) with that of a rough LPS mutant. IcsA* was located on lateral and polar regions of smooth LPS bacteria, and was fully functional in ABM assays (HeLa cell monolayer plaque and F-actin comet tail formation) which contrasts with the R-LPS phenotype. This indicates that loss of polar IcsA localisation in R-LPS mutants is unrelated to their ABM defect, and suggests that Oag may directly contribute to IcsA-mediated ABM.  相似文献   

13.
淡色库蚊三种有机磷抗性品系的相对适合度分析   总被引:3,自引:1,他引:2  
本文在淡色库蚊的敌百虫、双硫磷和毒死蜱三种抗性品系筛选的基础上,通过抗性品系和敏感品系的吸血、繁殖、存活和发育等生物学特性的测定和比较,组建实验种群生命表,分析抗性品系的适合度。结果表明:三种抗性品系的吸血率、产卵率和发育速率与敏感品系相比都有所降低,抗敌百虫品系、抗双硫磷品系和抗毒死蜱品系相对敏感品系分别具有:0.542、0.631和0.618的适合度。  相似文献   

14.
Shigellosis is a major cause of infant morbidity and mortality in developing countries. To find immunological correlates of specific protection against shigellosis, we examined chronological samples of sera, stool extracts, duodenal aspirates, and saliva samples from 39 adults and 22 children with shigellosis from Peru for the presence of specific antibody to invasion plasmid antigens (Ipa) common to all virulent Shigella strains, by using both a whole-organism enzyme-linked immunosorbent assay (ELISA) and a Western blot (immunoblot) assay. Antibody responses to lipopolysaccharide (LPS) from Shigella serotypes both homologous and heterologous to the infecting strain were also determined by ELISA. ELISAs showed that the highest serum immunoglobulin G (IgG) antibody titers to Shigella whole organisms both with and without surface Ipa were found in adults and malnourished children, the two groups with the shortest and longest durations of disease, respectively. Mucosal IgA antibody titers to Shigella strains decreased over time to a much greater extent than serum IgG titers, and IgA to Ipa in mucosal secretions was found in adults and well-nourished children but not in malnourished children. The presence of mucosal antibody to Ipa may limit the spread and severity of the infection, as indicated by the prolonged illness observed in malnourished children who have no significant mucosal antibody to Shigella Ipa. Serum antibody titers to the Ipa antigens were high relative to anti-Shigella LPS antibody titers, especially in pediatric patients. In contrast to the anti-Ipa responses observed, no differences in antibody responses to LPS in children compared by nutritional status were found. High levels of serum and mucosal cross-reacting antibody to heterologous serotype LPS were found between Shigella flexneri serotypes 1a and 2a. Different patterns of immune response to Ipa proteins and LPS that may aid in the definition of Shigella antigens important in host protection were observed in adults, well-nourished children, and malnourished children.  相似文献   

15.
为了研究侵袭蛋白与免疫保护的关系 ,为志贺菌苗的研制提供理论依据。经志贺菌苗角结膜免疫豚鼠 ,毒株攻击 ,观察侵袭蛋白对免疫保护的影响 ,观察到表达侵袭蛋白的菌苗较不表达侵袭蛋白的菌苗对毒株攻击有较高的保护率 ;用BA ELISA方法检测免疫后豚鼠泪液中特异性抗体水平 ,其结果较对照显著升高。说明侵袭蛋白的表达有一定的增加菌苗的免疫保护作用  相似文献   

16.
Escherichia coli strain R1, originally isolated from a patient whose burns were treated with silver sulphadiazine, contained two large plasmids of 83 kb (pJT1) and 77 kb (pJT2), and was resistant to 1 mM AgNO3. A silver-sensitive derivative, E. coli S1, cured of the 83-kb plasmid pJT1, was obtained by growth at 46 degrees C. Studies with an Ag+-specific ion electrode showed no significant differences in Ag+ binding by washed resting cell suspensions of strains R1 and S1, with and without glucose. However, transmission electronmicroscopy and energy dispersive X-ray analysis of whole cell mounts from actively growing cultures showed that the Ag+-resistant strain did not accumulate Ag+, whereas the sensitive strain contained dense silver particles. Both strains produced H2S, detected by blackening of lead acetate paper above inoculated broth, and reducing substances (possibly H2S) were detected only around E. coli R1 colonies when methylene blue was used as a indicator in LB agar, which may be a less sensitive assay. The mechanism of silver resistance is not known, but actively growing cells of E. coli R1 did not accumulate silver.  相似文献   

17.
Two haplotypes which posed difficult problems in serological identification, those of the HW and MNR/N strains, were studied. The HW strain was originally described as a unique haplotype (H-1h), but breeding difficulties precluded its detailed serological analysis. The red blood cells of the HW strain agglutinate weakly and cross-react with antisera to the Ag-B8 group. Anti-HW antisera cross-react strongly with LEW, ACI and WKA, but absorption with these strains did not produce an adequate typing serum. By judicious selection of recipients, however, an appropriate typing reagent could be made; a particularly useful one was (BUF × MR)F1 anti-HW absorbed with WKA red blood cells. The HW haplotype segregated appropriately in a (DA × HW)F2 population. The HW strain is a low responder to poly (Glu52Lys33Tyr15). The H-1h haplotype of this strain was designated Ag-B12. The MNR/N strain had not previously been studied serologically, although its MLR type had been defined as H-1c (MLR-5). Antisera to MNR/N crossreacted strongly with the H-1a, b, d, f haplotypes, but MNR/N red blood cells agglutinated only weakly with many antisera. An operationally monospecific reagent antiserum to the MNR/N haplotype could not be made. The uniquencess of the MNR/N haplotype was shown by F1 tests with LEW.1A, LEW.1D and LEW.1F, by various serological analyses, including production of antisera against MNR/N and in the MR strain; by segregation studies with (LEW × LEW.1D)N5 and (DA × DA.MNR)N4 segregating back-cross populations, and by grafting skin from (DA × DA.MNR)N4 homozygous and heterozygous animals to DA recipients. The MNR/N strain is a high-responder to poly (Glu52Lys33Tyr15). The MNR/N haplotype of this strain was designated Ag-B13 (H-1m). The data led to the working hypothesis that the MNR/N strain may be a recombination between the A region of H-1d and the B region of H-1c. In addition, the H-1d private specificity at the A region was probably lost by a deletion mutation which left the main complex of public specificities intact.  相似文献   

18.
In studies of the resistance of inbred mice to infection with Trypanosoma cruzi Peru, mouse strain B10.S was the only strain which survived the infection resulting from the inoculation of 10(3) trypomastigotes. This is the only inbred mouse strain studied to survive infection. To investigate the effect of the H-2 haplotype on survival, C57BL/10 congenic mouse strains bearing H-2S recombinant haplotypes and mouse strains A.SWSn/J and SJL/J were tested for their ability to overcome the T. cruzi infection. None of the recombinant strains tested, including B10.S(7R), B10.S(8R), B10.S(9R), and B10.HTT, survived the infection, indicating that at least two or more regions of the H-2 locus must be H-2S to ensure survival. Strains A.SWSn/J and SJL/J with the H-2S haplotype did not survive, indicating that the genetic background outside the H-2 complex also influences survival. The congenic F1 hybrid (C57BL/10 X B10.S) F1 exhibited intermediate survival levels when compared with the parental strains, indicating that H-2S survival is affected by gene dosage. The F1 hybrid strain [B10.S(7R) X B10.S(8R)]F1, which possesses the complete H-2S haplotype in the trans configuration, did not survive T. cruzi infection, suggesting that H-2S-mediated survival does not operate by trans complementation.  相似文献   

19.
蝌蚪提取液对HeLa细胞作用机理的探讨   总被引:3,自引:1,他引:2  
白经修  丁蔚 《解剖学报》1993,24(1):68-72,T009
  相似文献   

20.
Cu-Zn superoxide dismutase (SOD) deletion mutants of Brucella abortus S2308, a virulent strain, and S19, a vaccine strain, were generated by gene replacement. A deletion plasmid, pBA delta sodknr, was constructed by excising the Cu-Zn SOD gene (Cu-Zn sod) from a 2.3-kb B. abortus DNA fragment of plasmid pBA20-1527 and inserting a 1.4-kb DNA fragment encoding kanamycin resistance into the Cu-Zn sod excision site. The deletion plasmid was introduced into B. abortus by electroporation, and Southern blot analysis confirmed that the antibiotic resistance fragment had replaced Cu-Zn sod in kanamycin-resistant colonies. The survival and growth of Cu-Zn SOD mutant strains were compared with that of the parental strains in HeLa cells and in the mouse macrophagelike cell line J774. The survival and growth of the Cu-Zn SOD mutant strains were similar to those of their respective parental strains in HeLa and J774 cell lines. The kinetics of infection with these strains were examined in BALB/c mice. The splenic levels of the S19 Cu-Zn SOD mutant recovered from intraperitoneally infected BALB/c mice were approximately 10-fold lower than those of the parental strain through 26 days postinfection. Thereafter, infection sharply declined in both groups, and by 105 days postinfection, no organisms were detected. The splenic levels of the S2308 Cu-Zn SOD mutant were lower than those of wild-type S2308-infected mice. The spleen weights of mice infected with the S2308 Cu-Zn SOD mutant were consistently lower than those of wild-type S2308-infected mice. These results suggest that the antioxidant enzyme Cu-Zn SOD plays a role in the survival and pathogenicity of B. abortus in vivo.  相似文献   

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