OBJECTIVETo establish a three-step purification method of preparative-scale antiCD20 (Fab')2 using AKTA prime.

METHODSAntiCD20 (Fab')2 was extracted by hyperosmotic solution and then purified by CM sepharose FF, phenyl sepharose FF, and protein G sepharose FF.

RESULTSAround 8 mg anti-CD20 (Fab')2, whose purification was 96.678%, was purified. The antigen-binding activity of antiCD20 (Fab')2 was similar to that of antiCD20 (Fab')2 purified by protein G sepharose FF and S-100.

CONCLUSIONThe three-step purification method can obtain high-purity preparative-scale antiCD20 (Fab')2 in a simple way.

Antibodies ; immunology ; isolation & purification ; Antigens, CD20 ; immunology ; Chromatography ; methods ; Humans ; Immunoglobulin Fab Fragments ; immunology ; isolation & purification

OBJECTIVETo establish an improved procedure for isolation and identification of epitopes from a random peptide library displayed on the bacterial surface.

METHODSEpitopes were screened from FliTrx random peptide library by a monoclonal antibody 3B9 against HBV-PreS2 protein. The enrichment was monitored in each round. Higher affinity clones were obtained by increasing the washing strength and randomly selected for sequencing and Western blot analysis.

RESULTSClones specifically binding to antibody were enriched in each round. Ten sequences were obtained from sixteen sequenced clones, seven of them contained the common motif RXRGXY with high homogeneity to 135-140 amio acids in HBV-PreS protein and have positive results in Western blot analysis. The other three sequences have no typical motif RXRGXY and showed different Western blot results.

CONCLUSIONSIt's easy and quick to drive epitopes from a random peptide library displayed on the bacterial surface.

Amino Acid Sequence ; Animals ; Antigens, Viral ; immunology ; Bacterial Proteins ; immunology ; Flagellin ; immunology ; Hepatitis B Surface Antigens ; genetics ; immunology ; isolation & purification ; Immunodominant Epitopes ; immunology ; Molecular Sequence Data ; Peptide Library ; Protein Precursors ; genetics ; immunology ; isolation & purification

OBJECTIVETo evaluate the accuracy of the Helicobacter pylori (H. pylori) stool antigen (HpSA) test and ImmunoCard STAT HpSA in the primary diagnosis of H. pylori infection.

METHODSWe searched Medline (1966-2007.4), EMbase (1985-2007.4), Chinese Journals Full-text Database (CJFD) (1994-2007) etc. to identify Clinical Trials of ImmunoCard STAT HpSA for the primary diagnosis of H. pylori infection. Meta-analysis was conducted using the method recommended by The Cochrane Collaboration Center.

RESULTSEleven trials were included with pooled sensitivity, pooled specificity as 0.93 (95% CI: 0.91-0.94), 0.93 (95% CI: 0.90- 0.95), respectively. Pooled positive likelihood ratio and pooled negative likelihood ratio were 12.01 (95% CI: 8.90-16.19), 0.08 (95% CI: 0.07-0.11), respectively with the pooled diagnostic odds ratio as 160.14(95% CI :100.43-255.34). The area under the summary receiver operating characteristic (SROC) was 0.974 +/- 0.005.

CONCLUSIONImmunoCard STAT HpSA appeared to be an accurate non-invasive method for the initial diagnosis of H. pylori infection.

Antigens, Bacterial ; immunology ; Feces ; microbiology ; Helicobacter Infections ; diagnosis ; immunology ; Helicobacter pylori ; immunology ; isolation & purification ; pathogenicity ; Reagent Kits, Diagnostic ; Sensitivity and Specificity

This article aimed to study the antigenicity of nucleocapsid proteins (NPs) in six pathogenic phleboviruses and to provide theoretical evidence for the development of serological diagnostic reagents. NPs of six pathogenic phleboviruses were expressed and purified using a prokaryotic expression system and rabbits were immunized with individual recombinant NPs. Cross-reactions among NPs and rabbit sera were determined by both indirect ELISA and Western blotting analyses, and the sera titer was determined by indirect ELISA. Furthermore, sera from SFTS patients were also detected by each recombinant NP as a coating antigen using indirect ELISA. The cross-reactions and the sera titer were subsequently determined. Both the concentration and purity of recombinant NPs of six pathogenic phleboviruses met the standards for immunization and detection. The results of indirect ELISA and Western blotting showed that each anti-phlebovirus NP rabbit immune serum had potential serological cross-reactivity with the other five virus NP antigens. Furthermore, the sera from SFTS patients also had cross-reactivity with the other five NP antigens to a certain extent. Our preliminary study evaluated the antigenicity and immune reactivity of six pathogenic phleboviruses NPs and laid the foundation for the development of diagnostic reagents.
Animals ; Antibodies, Viral ; immunology ; Antigens, Viral ; genetics ; immunology ; Cross Reactions ; Humans ; Nucleocapsid Proteins ; genetics ; immunology ; Phlebotomus Fever ; diagnosis ; immunology ; virology ; Phlebovirus ; classification ; genetics ; immunology ; isolation & purification ; Rabbits

Antigens, Bacterial ; immunology ; Antigens, Surface ; immunology ; China ; epidemiology ; Diarrhea ; microbiology ; Escherichia coli Infections ; epidemiology ; microbiology ; Escherichia coli O157 ; classification ; immunology ; isolation & purification ; Humans

House dust mites produce inhalant allergens of importance to allergic patients. We measured the major group 1 allergens, Der p 1 and Der f 1, from the house dust mites Dermatophagoides pteronyssinus and Dermatophagoides farina, respectively in 100 randomly selected domestic homes from Cheonan, Korea. Dust samples were collected by vacuuming from the living room floor and 1 mattress in each home. Der p 1 and Der f 1 were measured by double monoclonal ELISA. Der p 1 levels were very low, with geometric mean levels for floors and mattresses being 0.11 microgram/g (range: 0.01-4.05) and 0.14 microgram/g (range: 0.01-30.0), respectively. Corresponding levels of Der f 1 were higher, 7.46 microgram/g (range: 0.01-262.9) and 10.2 microgram/g (range: 0.01-230.9) for floors and mattresses, respectively. D. farinae appears to be the dominant house dust mite in Cheonan.
Animals ; Antigens, Dermatophagoides/immunology/*isolation & purification ; Bedding and Linens ; Dust/analysis ; Floors and Floorcoverings ; Housing ; Humans ; Korea ; Pyroglyphidae/*immunology

OBJECTIVETo investigate the virulence characteristics of two fixed strains (CTN and aG) and a street strain (HN10) of rabies viruses isolated in China.

METHODSICR mice of different age groups were inoculated with CTN, aG and HN10 rabies virus strains via the intracracerebral (i.c.) or intramuscular (i.m.) routes, and observed for 20 days.

RESULTSThe CTN strain was pathogenic to 7-day-old suckling mice that received i.c. inoculations and 3-day-old suckling mice that received i.m. inoculations. The aG strain was pathogenic to 4-week-old mice that received i.c. inoculations and 7-day-old suckling mice that received i.m. inoculations. The HN10 strain was pathogenic to mice of all age groups via both inoculation routes. In moribund mice, the viruses had spread to most regions of the brain. The CTN and HN10 strains had similar dissemination patterns in the brain; both viral antigens could be found in the dentate gyrus (DG), whereas few viral antigens were present in the DG from specimens that had been infected with the aG strain.

CONCLUSIONA comprehensive sequence analysis of the G protein suggested that differences in gene sequences may be responsible for producing strain-specific differences in pathogenicity and distribution in the brain.

Animals ; Antigens, Viral ; immunology ; Brain ; immunology ; virology ; China ; Mice ; Mice, Inbred ICR ; Nucleocapsid Proteins ; immunology ; Rabies ; virology ; Rabies virus ; immunology ; isolation & purification ; pathogenicity

OBJECTIVETo prepare eukaryotic expression of rotavirus (RV) SA11 capsid protein VP7, and to generate and purify yolk immunoglobulin (IgY) antibodies against the recombinant VP7 from Roman hens.

METHODSMA104 cells were infected with the standard SA11 strain and the culture fluid was collected. A DNA fragment of 978 bp encoding SA11 VP7 was obtained by RT-PCR amplification from genomic RNA of RV SA11. The PCR products were ligated to pMD18-T vector following the confirmation by DNA sequencing and sub-cloned into pPICZalphaB. The recombinant pPICZalphaB-SA11 VP7 was transformed into E coli Top10. The plasmids were linearized by digestion of BstXI and transformed into Pichia pastoris X-33 through electroporation by DNA sequencing. The transformants were induced with methanol for expression. The cultural supernatant was subjected to SDS-PAGE and Western blotting. Fusion expression was purified through the column of affinity chromatography. IgY was identified and purified by SDS-PAGE and Western blotting from eggs of Roman hens immunized with recombinant SA11 VP7.

RESULTSThe RNA extracted from the RV culture fluid consisted of 11 bands visualized by silver staining. The expression vector pPICZalphaB-SA11 VP7 was constructed and the fusion protein in Pichia pastoris X-33 was harvested and purified. The recombinant SA11 VP7 with molecular weight of 40 200 was identified by Western blotting. The IgY antibodies against the recombinant SA11 VP7 were produced with a purity of 95 percent and yield of 10.2 mg per egg.

CONCLUSIONThe preparation of IgY antibodies to recombinant SA11 VP7 might lay a foundation for the development of vaccines and diagnostic techniques.

Animals ; Antigens, Viral ; genetics ; immunology ; metabolism ; Capsid Proteins ; genetics ; immunology ; metabolism ; Chickens ; Cloning, Molecular ; Immunoglobulins ; immunology ; isolation & purification ; Recombinant Proteins ; genetics ; immunology ; metabolism

OBJECTIVETo develop a technology for production of recombinant SAG1 of Toxoplasma gondii (T.g) in batches.

METHODSThe rSAG1 of T.g was expressed in E.coli by high-density fermentation and purified by Sephadex G-75 column chromatography after Ni-NTA agarose at native condition. The activity of rSAG1 and its efficacy in T.g diagnosis were identified by Western blotting and ELISA, respectively.

RESULTSThe optical density (OD) of the bacteria reached 20.21 after induction, and 300 g bacteria were harvested from 11.5 L broth. The rSAG1 was highly expressed in E.coli as a fusion protein, accounting for about 25.82% of the total bacterial protein. The purity of rSAG1 reached 98.54% after purification by Ni-NTA combined with Sephadex G-75 column chromatography. Western blotting revealed a distinct band reacting with the sera of rabbits vaccinated by T.g. Twenty-four of the 25 sera of mice infected with T.g and 36 of the 38 sera of human subjects with IgG antibody against T.g were detected by rSAG1-ELISA.

CONCLUSIONA large-scale production of immunoreactive SAG1 of T.g is developed by high-density fermentation and purification with Ni-NTA combined with Sephadex G-75 column chromatography.

Animals ; Antigens, Protozoan ; biosynthesis ; genetics ; immunology ; Antigens, Surface ; immunology ; Blotting, Western ; Enzyme-Linked Immunosorbent Assay ; Escherichia coli ; genetics ; metabolism ; Fermentation ; Protozoan Proteins ; biosynthesis ; genetics ; immunology ; Recombinant Fusion Proteins ; biosynthesis ; immunology ; isolation & purification ; Toxoplasma ; immunology

Three different chemical carcinogens, 2-acetylaminofluorene (AAF), diethylnitrosamine(DENA), and 3'-methyl-4dimethylaminoazobenzene (3'-Me DAB) were used to induce hepatomas in rats. Plasma membrane surface proteins of normal rat liver cells and rat hepatomas were extracted with 3M KCI. From the analysis of the proteins of normal rat liver and rat hepatoma induced by 3'-Me DAB by discontinuous polyacrylamide gel electrophoresis(Disc-PAGE), under nonreducing and nondenaturing conditions polyacrylamide gel electrophoresis in the presence of SDS and 2-mercaptoethanol (SDS-PAGE), Sephadex G-200 gel permeation chromatography, DEAE-A50 ion-exchange chromatography and two-dimensional gel electrophoresis, at least three tumor specific antigens were identified. One had a molecular weigh of 66,000 (pl=6.79) while the other two had the same molecular weight 73,000 but differed in their isoelectric points (7.58 and 7.81). For immunological analysis of tumor specific antigens, the absorbed antiserum was prepared. Plasma membrane surface proteins of rat hepatoma induced by 3'-Me DAB were used to obtain New Zealand White male rabbit antiserum. Rabbit antiserum was then reacted with the proteins isolated from the plasma membrane surface of normal rat liver and the absorbed antiserum reacting specifically with the tumor specific antigens derived by 3'-Me DAB was obtained. Using the absorbed antiserum, the immunoreactivities of plasma membrane surface proteins isolated from rat hepatomas induced by 3'-Me DAB, AAF, and DENA were compared by Ouchterlony double immunodiffusion analysis and immunoelectrophoresis. To characterize the proteins reacting to the absorbed antiserum, immunoglobulin G was separated from the absorbed antiserum and coupled to cyanogen bromide-activated Sepharose CL-4B. The isolated proteins from the plasma membrane surface proteins of 3'-Me DAB-induced hepatoma using this immunoaffinity chromatography had molecular weights of 66,000 and 73,000. The localization of these proteins on surface plasma membranes of rat hepatomas induced by 3'-Me DAB was confirmed by an immunofluorescence technique. The experimental results revealed the existence of cross-reacting common antigens on the plasma membrane surface of rat hepatomas induced by different hepatocarcinogens.
2-Acetylaminofluorene ; Animal ; Antigens, Neoplasm/*isolation and purification ; Antigens, Surface/isolation and purification ; Diethylnitrosamine ; Liver Neoplasms, Experimental/chemically induced/*immunology ; Methyldimethylaminoazobenzene ; Rats ; Rats, Inbred Strains ; Support, Non-U.S. Gov't