| Helicobacter pylori (H. pylori} chronically infects up to 50% of the world's human population, responsible for chronic gastritis, peptic ulcer disease, gastric cancer and gastric mucosa-associated lymphoid tissue (MALT) lymphoma in humans. A multitude of nongastric conditions including atherosclerosis, allergic skin diseases, hepatic encephalopathy, childhood anemia, and growth retardatio have also been identified to associated with H. pylori infection. The pathogenicity of H. pylori comes from its virulence. Many factors contribute to the virulence of Hp, including colocalization, adherence, and virulence associated factors on which the research reports are more and more increased and integral. The CagA cellular transport by pathogenicity island (PAI) and the associated host cell signal transduction have been reported recently. Except for H. pylori virulence, individual diversity on genetic predispositions to infection and pathogen-host interaction are also veryimportant for diseases development. The H. pylori infection is now treated with antibiotics, but drug resistance become very popular. So vaccines are in need and clinical trials are being prepared. The detection of//, pylori infection now are mostly monomial, aiming to find out whether or not an individual infection with H. pylori. Proteome analysis of H. pylori should be the further interesting fields for future work.Biochip is based on the interaction of the biological macromolecules, mainly including gene chip and peptide chip, can get a great deal analysis information in parallel in a sample reaction simultaneously. High-density protein microarrays can be applied to protein function studies, screening the production of antibodies and recombinant proteins, the used solid phase are slides, polyvinylidenedifluoride, EjLISA plate and nylon membrane to carry out high-throughput qualitative or quantitative analysis. The label technology is often fluorescence to be scanned by automatized instrument. Colloid gold are widely applied in detection or diagnosis of disease. The characteristic of it is rapid, simple, and steady <=The genome of Hp is well known and large amounts of reports published on virulence-associated factors of Hp allow the application of biochip on detection or diagnosis of Hp infection.The 5 ' cagA section of 850bp had been cloned into pBV220 and expressed in E.coli before named as CO. Based on it. the remainder was amplified into three truncts to contain the full length of the open reading frame of the cagA gene. After sequenced, they were subcloned into the prokaryotic fusion expression vector pRSETA. Then three recombinant CagA trunct antigens named as His6Cl, His6C2, His6C3 were expressed in E.coli BL21 DE3 by IPTG induction respectively. All of them were expressed as inclusion bodies. The relative molecular mass (Mr) of His6Cl, His6C2 and His6C3 were37000, 28000 and 42000. After electrophoresis of C1 and C2 denatured samples, they were transferred to PVDF membrane. Then rabbit polyclonal antiserums were produced against Cl and C2 by immunizing rabbits withPVDF membrane containing the Cl and C2 bands. Both of the titer of antiserum against Cl and C2 were 1:16000, suggesting the good immunogenic activities of recombinant CagA trunct antigens.After inclusion body preparation were got and denatured, denatured sample were diluted with 30 volumes refolding buffer (pH 8.3 ) containing 50mM L-Arg at 4癈 for CO. The solution was then applied to anion-exchange HPLC. CO were eluted at about 0.35 M NaCl after a 0.15 M NaCl elution to remove other proteins. His6.CK His6-C2 fn His6-C3 were dissolved under denatured conditions and purified by a single step using Ni+-NTA. The His6 fusion protein can be eluted with 0.5mol.L~' imidazole contained elution buffer, revealed more than 90% purity and good activity in ELISA and DIGFA after renature and dialysis. Anti-CagA antibody can be detected in different proportion between .gastric cancer patient and healthy controls. The gastric cancer subjects were more likely than the health...
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