Antibodies, Bacterial ; blood ; Antigens, Bacterial ; biosynthesis ; Bacterial Proteins ; biosynthesis ; Carrier Proteins ; biosynthesis ; Gastritis ; microbiology ; Helicobacter Infections ; immunology ; Helicobacter pylori ; immunology ; isolation & purification ; Humans ; Recombinant Proteins ; biosynthesis

OBJECTIVETo prepare and identify monoclonal antibodies (mAbs) against Helicobacter pylori (Hp).

METHODSBALB/c mice were immunized with the supernatant and precipitation of cultured Hp after ultrasonication and mAbs were obtained by means of hybridoma technique. The resultant mAbs was evaluated for subtype, titer, affinity, and further identified with Lpp20, HspA, urease A, CagA, urease B, and catalase prepared by recombinant expression.

RESULTSTotally 34 hybridoma cell lines were established which secreted specific mAbs, including 31 against the supernatant and 3 against the precipitation of Hp, and the prepared mAbs showed specific reaction against Lpp20 (3 strains), HspA (2 strains), urease A (4 strains), CagA (1 strain), urease B (5 strains), and catalase (2 strains) antigens, respectively. The mAbs was all identified as immunoglobulin G1 (IgG1) and theirs titer in the culture supernatant and ascites was 1:16 to 1:32 and 1:32000 to 1:64000 respectively with affinity constants (K(aff)) ranging from 1 x 10(-10) to 5.2 x 10(-12) mol/L.

CONCLUSIONThe mAbs specially against Hp have been obtained, which may facilitate further study of detection and vaccine development of Hp.

Animals ; Antibodies, Bacterial ; biosynthesis ; immunology ; Antibodies, Monoclonal ; biosynthesis ; immunology ; Antibody Specificity ; Female ; Helicobacter pylori ; immunology ; Humans ; Hybridomas ; immunology ; Mice ; Mice, Inbred BALB C

OBJECTIVETo prepare the polyclonal antibody against methyl-accepting chemotaxis signal transduction protein (MCP) of Helicobacter hepaticus (H.hepaticus).

METHODSThe recombinant plasmid pET22b+/MCP was transformed into E.coli BL2l(DE3) to express the fusion protein His-rhMCP under the induction of IPTG. The fusion protein was purified and the antibody was obtained by immunizing rabbits. The titer of the polyclonal antibody was tested by indirect ELISA, and the specificity of the antibody was identified based on Western blotting using the prepared cell surface proteins (CSPs) of the bacteria.

RESULTSThe fusion protein was successfully expressed, and the titer of the antibody reached 1:32 000. Western blotting indicated that the antibody could specifically bind to CSPs and His-rhMCP.

CONCLUSIONThe antibody with a high titer and specificity was prepared to facilitate further study of the pathogenicity and epidemiology of H.hepaticus in human.

Animals ; Antibodies, Bacterial ; biosynthesis ; genetics ; Antibody Specificity ; Bacterial Proteins ; immunology ; Helicobacter hepaticus ; immunology ; metabolism ; Male ; Mice ; Mice, Inbred BALB C ; Rabbits ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; Signal Transduction

We evaluated tetanus specific IgG, IgM, IgG subclasses after DPT vaccination in infants and children. Tetanus toxoid specific IgG, IgM IgG subclasses were measured to characterize the isotope profile of antibody against tetanus toxoid. The values of the tetanus specific IgG in the positive group were significantly increased compared to those of the control group, and were significantly increased after two inoculation. Tetanus specific IgG was very low in adults and neonates. In our tetanus specific IgG subclasses study, forty-five of 56 cases (80%) showed predominantly IgG1 antibody responses to tetanus toxoid, while twenty-five of 56 cases (45%) showed IgG4 responses. Both IgG1 and IgG4 responses were demonstrated in 17 cases (30%). So we suggest that IgG was mainly involved in humoral immune response after DPT vaccination, and IgG1 may play an important role among IgG subclasses. IgG4, alone or together with IgG1, can also play a role in immune response to tetanus toxoid.
Antibodies, Bacterial/*biosynthesis ; Antibody Specificity ; Child ; Clostridium tetani/immunology ; Diphtheria-Tetanus-Pertussis Vaccine/*immunology ; Human ; Immunoglobulin G/biosynthesis/classification ; Immunoglobulin M/biosynthesis ; Infant

Induced by 42 degrees C, the recombinant engineering bacterial pBV/cpa408 was highly expressed. After having been pelleted by 80% (NH4)2 SO4 and dialysised, the expressed protein was isolated and purified by the gel filtration choromatography. Then according to an amount of 1.0 mg/kg, the Kunming Mice (body weighted 18g) were immuned with the purified protein by intraperitoneal inoculation. One week after the first enhanced immunization, the Kunming Mice were attacked with an amount of 1.0MLD alpha-toxin, in which the eight mice immuned all survive and the control group all died. During the period of immunization, the titre of the mouse's serum antibody was measured by ELISA. One week after the first immunization, the titre of the mice's serum antibody was 1:800, but that of one week after the first enhanced immunization reached to 1:6400.
Animals ; Antibodies, Bacterial ; blood ; Antigens, Bacterial ; biosynthesis ; immunology ; Bacterial Toxins ; immunology ; Calcium-Binding Proteins ; immunology ; Female ; Immunization ; Male ; Mice ; Recombinant Proteins ; biosynthesis ; immunology ; isolation & purification ; Type C Phospholipases ; immunology

The purified elementary bodies of C. pneumoniae TW-183 were used for immunization of male BALB/c mice, the spleen cells of these mice were fused with SP2/0 cells and the hybrid cells were cloned by limiting dilution. One clone that secreted the C. pneumoniae monoclonal antibody (Cpn-McAb) stably was obtained finally. The Cpn-McAb belonged to IgG2b class and anti-Cpn-MOMP; the outcome of micro-immunofluorescence showed its weak cross reaction with the C. psittaci elementary body but it has no cross reaction with C. trachoma elementary body. It has the same speciality of the imported Cpn-McAb. For the evaluation of Cpn-McAb, the peripheral blood mononuclear cell specimens of 454 patients were detected by self-made Cpn-McAb and imported Cpn-McAb at the same time. The positive rates of Cpn-antigen were 53.3% for self-made Cpn-McAb and 52.6% for imported Cpn-McAb,showing high concordance between them (Kappa=0.714). The results showed that self-made Cpn-McAb has almost the same high specificity and sensitivity as imported Cpn-McAb, so the self-made Cpn-McAb may replace imported Cpn-McAb to detect Cpn specific antigen and be helpful to diagnosing and treating the clinical diseases associated with Cpn infection.
Animals ; Antibodies, Bacterial ; immunology ; Antibodies, Monoclonal ; biosynthesis ; genetics ; Antibody Specificity ; Chlamydia Infections ; diagnosis ; microbiology ; Chlamydophila pneumoniae ; immunology ; Hybridomas ; secretion ; Male ; Mice ; Mice, Inbred BALB C

OBJECTIVETo construct recombinant plasmids containing the truncated gene of the major surface antigen sta56 of Orientia tsutsugamushi (Ot.) Karp strain for expression antigen in E. coli so as to compare the expression efficiency in different systems.

METHODSFrom the recombinant plasmid TOPO-sta56 containing sta56 of Orientia tsutsugamushi Karp strain, several truncated genes of sta56 with different length were amplified and subcloned into the expression vectors pPROEX HTb and pET30a. These genes were expressed in E. coli DH5alpha and BL21(DE3) respectively when induced by IPTG. The expressed recombinant proteins were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot.

RESULTSSix recombinant plasmids containing truncated sta56 genes of different length were constructed as follow: pHTbOt957, pHTbOt498, pHTbOt342 and pETOt957, pETOt498, pETOt342. The recombinant sta56 proteins were highly expressed as 6 x His fusion proteins in E. coli DH5alpha and BL21(DE3) respectively. The fusion proteins showed as different bands of different molecular weight respectively when analyzed with SDS-PAGE. Western blot demonstrated that the recombinant proteins were recognized by the positive serum of Ot. patients.

CONCLUSIONThe sta56 gene of Orientia tsutsugamushi Karp strain could be highly expressed in E. coli and its expression showed better efficiency in pET30a than in pPROEX HTb. The recombinant sta56 antigen with immunoreactivity could be used as diagnostic reagent for Ot. infection.

Animals ; Antibodies, Bacterial ; biosynthesis ; Antigens, Bacterial ; biosynthesis ; genetics ; immunology ; Bacterial Proteins ; biosynthesis ; genetics ; immunology ; Cloning, Molecular ; Escherichia coli ; genetics ; metabolism ; Genetic Vectors ; Humans ; Membrane Proteins ; biosynthesis ; genetics ; immunology ; Orientia tsutsugamushi ; immunology ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; immunology ; Scrub Typhus ; immunology ; prevention & control

Diphtheria toxin A fragment (DTA) is an essential catalytic domain of diphtheria toxin (DT)-based immunotoxin. DTA protein and its antibodies play an important role in the studies on toxicology, purification and identification of DT-based immunotoxins. In this paper, DTA was expressed and purified from E. coli. After Q-Sepharose FF chromatography and (Ni+)-Sepharose affinity chromatography, 6 x His-DTA fusion protein with 90% purity was achieved. Using the purified DTA as antigen to immunize BalB/c mice, 2 hybridoma cell lines (designated as 3B6 and 3B9, respectively) secreting monoclonal antibodies (McAbs) against DTA were established. Investigations showed that both McAbs were characterized as IgG1 with titers of 1: 10(6). The binding of the McAbs to DTA was competitively inhibited by horse sera against DT. The fact that anti-DTA McAbs could be used in western blot analysis and affinity chromatography purification of DT-based immunotoxins implied that they will be useful agents in the studies on DT-based immunotoxins.
Animals ; Antibodies, Bacterial ; genetics ; Antibodies, Monoclonal ; biosynthesis ; genetics ; Chromatography, Affinity ; Diphtheria Toxin ; immunology ; Escherichia coli ; genetics ; Female ; Immunotoxins ; isolation & purification ; Mice ; Mice, Inbred BALB C ; Peptide Fragments ; immunology ; Plasmids ; Recombinant Fusion Proteins ; biosynthesis ; isolation & purification

The filtrate of Staphylococcus aureus culture has been used in an ampule form named as staphylococcal enterotoxin C injection for cancer therapy in clinic for ten years in China and proved to be effective. The active constituent of three kinds of injections is claimed to be staphylococcal enterotoxin C2 (SEC2), and the content of SEC2 is used as quality control. However, the correct content of SEC2 was not known and the relative amount of SEC2 was very low because of the complicated components of the filtrate. In this research, we established a proper ELISA system for the detection of SEC2 in staphylococcal enterotoxin C injection, which will improve the quality control of the injection. We produced and identified polyclonal and monoclonal antibodies of SEC2 and established BA-ELISA method based on the method of sandwich ELISA. It was found that the BA-ELISA method had good specificity, sensitivity and reproducibility, and being able to detect SEC2 at concentration from 2 to 20 ng x mL(-1), with an average CV value of 5.08%. The SEC2 content in staphylococcal enterotoxin C injection was calculated. There is some difference between the actual and labeled contents in the injections.
Animals ; Antibodies, Bacterial ; biosynthesis ; immunology ; Antibodies, Monoclonal ; biosynthesis ; immunology ; Antineoplastic Agents ; administration & dosage ; analysis ; immunology ; Enterotoxins ; administration & dosage ; analysis ; immunology ; Enzyme-Linked Immunosorbent Assay ; methods ; Hybridomas ; secretion ; Injections ; Mice ; Mice, Inbred BALB C ; Quality Control ; Rabbits ; Staphylococcus aureus ; chemistry

A 21-kDa leptospiral lipoprotein (LipL21) was evaluated for its diagnostic potential to detect bovine leptospirosis by ELISA. Both native LipL21 (nLipL21) and recombinant LipL21 (rLipL21) proteins were tested and compared regarding diagnostic efficiency, and no statistically significant difference was observed. The sensitivity of rLipL21 ELISA for 62 microscopic agglutination test (MAT) positive sera was 100% and the specificity with 378 MAT negative sera was 97.09%. Thus, rLipL21 protein-based ELISA could be used as an alternative to MAT for the diagnosis of bovine leptospirosis.
Animals ; Antibodies, Bacterial/blood ; Antigens, Bacterial/biosynthesis/*chemistry/genetics ; Bacterial Outer Membrane Proteins/biosynthesis/*chemistry/genetics ; Cattle ; Cattle Diseases/blood/*microbiology ; Enzyme-Linked Immunosorbent Assay/veterinary ; Leptospira interrogans/*isolation & purification ; Leptospirosis/blood/microbiology/*veterinary ; Lipoproteins/biosynthesis/*chemistry/genetics ; Recombinant Proteins/biosynthesis/chemistry/genetics ; Sensitivity and Specificity