ABSTRACT
@#ObjectiveTo obtain recombinant H.pylori adhesin A(rHpaA)by molecular cloning,protein expression and purification,immunize BALB/c mice to prepare anti-HpaA polyclonal antibody,and analyze its antibody specificity.MethodsThe three-dimensional structure and antigenic properties of rHpaA were analyzed by bioinformatics softwares such as Phyre2 and DNAstar;Adhesin HpaA gene was obtained by PAS(PCR-based accurate synthesis)and inserted into plasmid pCzn1.The prepared recombinant plasmid pCzn1-rHpaA was transformed to E.coli Artic Express(DE3),induced by IPTG and purified by Ni-IDA affinity chromatography to obtain rHpaA protein,which was identified for reactivity by Western blot.Six male BALB/c mice were immunized with rHpaA plus Freund's adjuvant to prepare anti-HpaA polyclonal anti-body,and the antibody specificity was identified by ELISA.ResultsrHpaA showed good three-dimensional structure and antigenic properties.Restriction analysis and gene sequencing showed that the recombinant plasmid pCzn1-rHpaA contained completely correct HpaA gene sequence.The recombinant strain pCzn1-rHpaA/Arctic Express expressed the soluble target protein rHpaA,which accounted for about 68.3% of total protein in the supernatant,with a purity of 98.1%.rHpaA bound to anti-His antibodies and anti-H.pylori antibodies;The anti-HpaA polyclonal antibody specifically recognized rHpaA and H.pylori lysates.ConclusionrHpaA protein with high purity can be obtained by induction at low temperature and purification.The prepared anti-HpaA polyclonal antibody had good specificity,which laid an experimental foundation of the development of H.pylori-related diagnostic reagents.
ABSTRACT
@#Objective To express and purify the E protein Domain Ⅲ(ED Ⅲ) of tick-borne encephalitis virus(TBEV) in tandem and prepare the corresponding polyclonal antibody.Methods The TBEV RNA was extracted by Trizol method,and then reversely transcribed into cDNA,which was used as template to amplify ED Ⅲ gene fragment by PCR.Two ED Ⅲ gene fragments were ligated into fusion gene by the hydrophobic flexible polypeptide(G_4S)_3 using overlapping PCR,which was then linked to prokaryotic expression vector pET-28a(+) to construct the recombinant expression plasmid pET-28a-2ED Ⅲ.After sequencing,pET-28a-2ED Ⅲ was transformed into E.coli BL21(DE3) competent cells,induced by IPTG and purified by Ni~(2+) affinity chromatography.Female New Zealand white rabbits were immunized with the renatured recombinant protein to prepare polyclonal antibody.The antibody titer was detected by indirect ELISA and the specificity was identified by Western blot.The homology of ED Ⅲ amino acid sequence between TBEV and other flaviviruses was analyzed by DNAMAN software.Results The recombinant plasmid pET-28a-2ED Ⅲ was identified by sequencing,and the amplified sequence contained two genes consistent with the E sequence of TBEV "Senzhang" strain(JQ650523.1) included on GenBank,indicating that the recombinant plasmid was constructed correctly.The recombinant 2ED Ⅲ protein was expressed mainly in the form of inclusion bodies,with a relative molecular mass of about 21 000 and a purity of 97.5%.The titer of rabbit anti-2ED Ⅲ serum polyclonal antibody was 1:10~7,which reacted specifically with TBEV whole virus.DNAMAN software alignment showed that the homology of ED Ⅲ amino acid sequences between TBEV and Japanese encephalitis virus(JEV),yellow fever virus(YFV) and Dengue virus(DENY) was 36.56%,9.28% and 30.77%,respectively.Conclusion The TBEV envelope ED Ⅲ tandem recombinant expression plasmid pET-28a-2ED Ⅲ was successfully constructed.The expressed recombinant 2ED Ⅲ protein had good reactivity and immunogenicity,and the prepared polyclonal antibody had high titer.
ABSTRACT
@#Objective To culture human sapovirus(HuSaV) GⅠ.1 in vitro and prepare polyclonal antibody against the capsid protein VP1.Methods HuSaV GⅠ.1 positive stool specimens preserved in diarrhea department of National Institute for Viral Disease Control and Prevention were inoculated with HuTu-80 cells supplemented with different bile acid salts[glycine chenodeoxycholic acid(GCDCA) and glycine cholic acid(GCA)],and the infection,proliferation and passage of the virus were determined by PCR and RT-qPCR.The VP1 gene was amplified by PCR and cloned into prokaryotic expression vector pGEX-6P-1.The constructed recombinant expression plasmid pGEX-6P-1-VP1 was transformed into E.coli BL21(DE3) and induced by IPTG.Two female New Zealand white rabbits were immunized with the purified recombinant VP1 protein for 4 times.The blood samples were collected 18,28,38 and 48 d after immunization,and the serum titers were detected by ELISA.Results HuTu-80 cells were effectively infected by HuSaV GⅠ.1 in the presence of bile acid salt GCA,and the proliferated virus were stably and continuously transmitted for three generations in HuTu-80 cells.The expressed recom-binant GST-VP1 protein showed a relative molecular mass of about 86 000,and about 60 000 after purification(GST tag excision).The titer of polyclonal antibody against HuSaV VP1 protein was over 1:12 800.Conclusion HuSaV was successfully isolated and cultured in vitro using HuTu-80 cells supplemented with bile acid salt,and polyclonal antibody with high titer against HuSaV VP1 protein was prepared,which laid a foundation of in-depth research of HuSaV identification,infection and pathogenesis.
ABSTRACT
Objective:To prokaryotically express a peptide fragment of 660 - 1468 amino acids in Neisseria gonorrhoeae NGO2105 protein, and to prepare and identify its polyclonal antibody. Methods:The pCold TF-NGO2105 660-1468 aa recombinant plasmid was transformed into the bacterium Escherichia coli BL21 (DE3) for protein expression. After the inclusion body protein was denatured and renatured, the target protein was purified. Then, BALB/c mice were immunized with the target protein to prepare a polyclonal antiserum; the antibody potency was evaluated by enzyme-linked immunosorbent assay, the specificity of the antibody against NGO2105 protein in Neisseria gonorrhoeae was analyzed by Western blot analysis, the affinity of the antiserum with Neisseria gonorrhoeae was analyzed by flow cytometry, and adhesion inhibition assay was performed to evaluate the inhibitory effect of anti-NGO2105 660-1468 aa antibody on the adhesion of Neisseria gonorrhoeae to human cervical epithelial ME-180 cells. Comparisons between different groups were performed by using t test. Results:The NGO2105 660-1468 aa protein was expressed as the inclusion body, and the soluble target protein was obtained by denaturation, renaturation, and purification. After immunization of mice with the target protein, the antiserum titer was 5.12 × 10 6, and flow cytometry showed that the antibody bound well to the Neisseria gonorrhoeae NGO2105 660-1468 aa. Adhesion inhibition assay showed that the anti-NGO2105 660-1468 aa antibody significantly inhibited the adhesion of Neisseria gonorrhoeae to ME-180 cells, and the inhibitory effect was concentration-dependent to some extent, with the adhesion rates of Neisseria gonorrhoeae treated with 20- and 40-fold dilutions of the anti-NGO2105 660-1468 aa antibody being 52.9% and 79.2% respectively, significantly lower than the adhesion rate in the untreated group (100%, t = 8.40, 5.29, P < 0.001, = 0.006, respectively) . Conclusion:The NGO2105 660-1468 aa protein was successfully expressed and purified, and a highly potent polyclonal antibody was prepared, which had a good affinity with Neisseria gonorrhoeae and an adhesion inhibition ability.
ABSTRACT
Objective:To establish and validate a fluorescence focus assay (FFA) for rapid titration of Japanese encephalitis virus (JEV) and to evaluate its application in the production of Japanese encephalitis vaccine.Methods:Recombinant JEV non-structural protein 1 (NS1) was expressed in a prokaryotic expression system. After purification, JEV-NS1 was used to immunize rabbits to induce polyclonal antibody. FFA was established with the polyclonal antibody to titer JEV. The accuracy of FFA was validated by comparing with plaque assay, and the specificity, precision, linearity, range and robustness of FFA were also validated. Twenty-eight batches of live-attenuated Japanese encephalitis vaccine were titrated with FFA and plaque assay to analyze the relationship between the two assays.Results:FFA established with polyclonal antibody against JEV-NS1 could be used to titrate JEV, and there was no cross reaction with other viruses (tick-borne encephalitis virus, yellow fever virus, coxsackievirus A2, coxsackievirus A4). Results of the validation tests showed that FFA met the requirement of quality control for live-attenuated Japanese encephalitis vaccine. FFA was more consistency than plaque assay.Conclusions:The established FFA could be used for virus titration in the production of live-attenuated Japanese encephalitis vaccine.
ABSTRACT
Objective:To express the head domain of influenza A virus hemagglutinin (HA) in a prokaryotic expression system and to evaluate its immunogenicity.Methods:The genes encoding the HA head domains of H1N1 and H3N2 influenza viruses were cloned into pET-22b(+ ) prokaryotic expression plasmid. After the induction with IPTG, the fusion proteins rH1N1-HA and rH3N2-HA containing HA head domain and His-tag were expressed and obtained from E. coli BL21. SDS-PAGE and Western blot was used to verify the expression of the recombinant proteins. Rabbits were immunized with multiple doses of the purified recombinant proteins to obtain polyclonal antibodies against the HA head domains of H1N1 and H3N2. The immunogenicity of the recombinant proteins was evaluated in BALB/c mice. Results:rH1N1-HA and rH3N2-HA induced protective antibodies (geometric mean titer ≥40) in mice and could be used as protective antigens. Polyclonal antibodies against rH1N1-HA and rH3N2-HA could be used as important materials for Western blot, ELISA and other immunological assays.Conclusions:The HA head domains prepared in this study could be used as protective antigens to induce protective antibodies in mice. Polyclonal antibodies against the HA head domains could be used for immunological and serological studies of influenza A viruses.
ABSTRACT
The risk of early acute rejection after kidney transplantation is relatively high, which severely affects the quality of life of the recipients. In 2009, Kidney Disease: Improving Global Outcomes (KDIGO) recommended that immune inducers should be included in the immune-inducing regime before kidney transplantation, aiming to provide certain strength of immunosuppression during this critical phase and effectively reduce the incidence of acute rejection following kidney transplantation. At present, the selection, efficacy and safety of immune inducers remain controversial among transplantation centers around the world. In this article, clinical efficacy of monoclonal antibodies including interleukin-2 receptor antagonist, alemtuzumab, rituximab and polyclonal antibody antithymocyte globulin in immune induction therapy before kidney transplantation were compared and literature review was performed at home and abroad, aiming to provide reference for promoting the individualized selection of immune inducers for kidney transplantation and improving the quality of life of recipients.
ABSTRACT
Objective: To provide a method for preparing a specific polyclonal antibody of ARG. Methods: Firstly, the technology of polymerase chain reaction(PCR)was adopted to amplify the AbArg gene encoding arginase in Agaricus bisporus. Then the recombinant plasmid pET-28a(+)-Arg was constructed and transformed into E. coli BL21 for the expression of fusion protein. Afterwards, the purified protein was used to immunize New Zealand white rabbits, and the serum samples were collected. Results: The prokaryotic expression plasmid pET-28a(+)-Arg was constructed and the results of SDS-PAGE analysis showed that the fusion protein existing in form of inclusion body was successfully induced and expressed. After purification, the fusion protein with high purity (above 90%)was obtained. The immunity serum titer was 51 200 and Western blotting results showed that the polyclonal antibody could specifically recognize ARG protein in A. bisporus. Conclusion: Polyclonal antibody anti-ARG was prepared successfully, which lays a foundation for the further study on the mechanism of arginine metabolism.
ABSTRACT
Objective To compare the clinical efficacy of different T lymphocyte polyclonal antibodies in renal transplantation from donor kidney of organ donation after citizen's death. Methods Clinical data of 691 donors and recipients undergoing renal transplantation from donor kidney of organ donation after citizen's death were retrospectively analyzed. According to different T lymphocyte polyclonal antibodies used for induction, all recipients were divided into the rabbit anti human T lymphocyte immunoglobulin (rALG) group (n=414) and rabbit anti human thymocyte immunoglobulin (rATG) group (n=277). The recovery of renal graft function in recipients of the two groups were collected, including the incidence of delayed graft function (DGF) and acute rejection (AR), and the changes of serum creatinine level after renal transplantation. The 1-year survival rate of the recipients and renal grafts was collected. The incidence of adverse effects within 1 year after operation was calculated. According to the DGF risk score of donors, all recipients were divided into 5 groups. The use proportion of rALG and rATG in the recipients of each group was calculated. Results The incidence of DGF in the recipients of rALG and rATG groups was 14.5% (60/414) and 11.9% (33/277), respectively. The duration of DGF in the recipients of rALG and rATG groups was (7±4) d and (12±7) d respectively, with no statistically significant difference between two groups (P > 0.05). The incidence of AR in the rALG group was 7.5% (31/414), significantly higher than 4.0% (11/277) in the rATG group (P < 0.05). The serum creatinine levels of recipients within 6 months after renal transplantation tended to gradually decline in both groups. In renal transplantation for donor kidney with a DGF risk score of 0-15, the use proportion of rALG was significantly higher than that of rATG. However, the use proportion of rATG was significantly higher than that of rALG in renal transplantation for donor kidney with a DGF risk score over 16 (P < 0.05). The 1-year survival rates of the recipients and renal grafts in the rALG and rATG groups were 99.8% and 99.6%, 98.1% and 98.2%, respectively. There was no significant difference between two groups (both P > 0.05). The incidence of acute pulmonary edema and leukopenia in the recipients of rATG group was significantly higher than that in the rALG group (both P < 0.05). Conclusions Both rALG and rATG can effectively reduce the incidence of DGF and AR and achieve good clinical efficacy after renal transplantation from donor kidney of organ donation after citizen's death. The incidence of leukopenia and acute pulmonary edema induced by rATG is higher than that by rALG in the renal transplant recipients.
ABSTRACT
OBJECTIVE@#To prepare the recombinant peptide MVF-HER3 I composed of the 183-227aa peptide segment of human epidermal growth factor receptor 3 (HER3 I) and the measles virus protein 288-302 peptide segment (MVF), and prepare polyclonal antibodies (PcAb) against this recombinant peptide.@*METHODS@#The MVF-HER3 I gene was synthesized chemically and subcloned into pET21b or pET32a plasmid containing Thioredoxin (Trx) tag gene. The recombinant plasmids were identified by endonuclease digestion. MVF-HER3 I was expressed in BL21(DE3) cells under an optimal bacterial expression condition. The fusion protein Trx-MVF-HER3 I was purified using nickel ion affinity chromatography, and the purified protein was digested by enterokinase to remove Trx tag. The digested mixture underwent further nickel ion affinity chromatography to obtain purified MVF-HER3 I. The purified MVF-HER3 I was used to immunize SD rats subcutaneously for preparing anti-MVF-HER3 I PcAb. The titer of PcAb was determined using ELISA. The bindings of anti-MVF-HER3 I PcAb to MVF-HER3 I, native HER3 and MCF7 cells were analyzed using immunoblotting, immunoprecipitation and laser confocal microscopy. The growth inhibition effect of the antibodies on MCF7 cells cultured in the absence or presence of NRG was assessed using sulforhodamine B.@*RESULTS@#The recombinant peptide gene could not be expressed alone, but could be efficiently expressed after fusion with Trx gene under optimized conditions. The fusion peptide MVF-HER3 I was successfully prepared from Trx-MVF-HER3 I. The anti-MVF-HER3 I PcAb, with a titer reaching 1: 512 000, specifically bound to MVF-HER3 I, recognized native HER3 and bound to the membrane of MCF7 cells. The obtained PcAb could dose-dependently inhibit the growth of MCF7 cells irrespective of the presence or absence of NRG.@*CONCLUSIONS@#We successfully obtained the recombinant peptide MVF-HER3 I and prepared its PcAb, which can facilitate further functional analysis of HER3 signaling pathway.
Subject(s)
Animals , Humans , Rats , Antibodies , Enzyme-Linked Immunosorbent Assay , Escherichia coli , Plasmids , Rats, Sprague-Dawley , Receptor, ErbB-3 , Allergy and Immunology , Recombinant Fusion ProteinsABSTRACT
Objective: To investigate the role of BBS protein in ciliary signal transduction by studying the pro- karyotic expression, purification and polyclonal antibody preparation of Chlamydomonas reinhardtii protein BBS4. Methods: Prokaryotic Expression Vector pET-28a(+)-bbs4 and pMAL-c2X-bbs4 were constructed by the cDNA sequence of bbs4 Gene from C. reinhardtii, and then transformed into Escherichia coli BL21(DE3)for protein expression. The fusion protein with maltose binding protein(MBP)and 6×His tag was obtained by inducing expression. The purified fusion protein 6×His-BBS4 were used to immunize New Zealand white rabbits and the antiserum was isolated from the blood collected from the ear vein. The titer of the antiserum was measured by indirect ELISA essay, the specificity of the antibody was tested by Western blotting method and immunofluorescence test. Results: Prokaryotic expression plasmids pET-28a(+)-bbs4 and pMAL-c2X-bbs4 were successfully constructed. The relative molecular weights of 6×His-BBS4 and MBP-BBS4 fusion proteins were 45 kDa and 85 kDa, respectively. The purity of the fusion proteins was more than 85%, and the concentration of the fusion proteins was more than 0.5 mg/ml. The proteins were used for immunization. The titer of the fusion proteins was 51 200. Western blotting showed a high specificity for the detection of C. reinhardtii CC-125. Prokaryotic expression of BBS4 protein of C. reinhardtii and preparation of polyclonal antibody were realized. Conclu- sion: The polyclonal antibody against BBS4 of C. reinhardtii was prepared successfully, which laid a foundation for further study on the role of BBS4 in ciliopathies.
ABSTRACT
Aims@#The current gold standard method for the detection of Campylobacter jejuni is the culturing method followed up by immuno-based detection method, of which, the ELISA is the most often used. Many commercial detection methods based on ELISA use monoclonal antibody preparations although polyclonal antibody can be more sensitive and cheaper to produce. In this study, a comparison of indirect and sandwich ELISA-based detection methods for the detection of C. jejuni using a commercial monoclonal and polyclonal antibody preparations was explored. @*Methodology and results@#An indirect and sandwich ELISA-based methods for the detection of C. jejuni was carried out using the same concentration of antibody (5 μg/mL) and the same concentration of the bacterium at 1×109 CFU/mL. At the pre-screening for optimum concentration of antibody to be used for both assay formats, the commercial monoclonal preparation gave a poor absorbance value of about 0.112 compared to 1.582 for the polyclonal antibody preparation. Hence, the use of the monoclonal antibody was not pursued further. Using the polyclonal antibody, the calculated Limits of Detection (LOD) value obtained for the indirect and sandwich ELISA methods were at 1.6×104 CFU/mL and at 1.29×104 CFU/mL, respectively, which are more sensitive than commercially used methods. The results of the specificity test obtained from the developed polyclonal antibody were then tested against other common food borne bacterial pathogens such as Salmonella Typhimurium, Listeria monocytogenes and Escherichia coli tested using the sandwich ELISA format indicated that the responses by other bacterial genus were relatively low with the translated cross-reactivity percentages of 1.78, 2.36, and 6.87%, respectively. @*Conclusion, significance and impact of study@#The results indicated that the developed system using a polyclonal antibody preparation can be more sensitive than monoclonal preparation. In addition, it is also specific towards Campylobacter while the monoclonal antibody preparation fares poorly.
ABSTRACT
To prepare polyclonal antibody (PcAb) against Escherichia coli filamentous thermosensitive protein Z (Ec-FtsZ), the artificially synthesized gene fragment coding Ec-FtsZ was subcloned into pET-22b(+) plasmid, and Ec-FtsZ protein was expressed in E. coli BL21(DE3) cell under an optimal bacterial expression condition. Then Ec-FtsZ protein was purified by HisTrap affinity chromatography, and the GTPase (Guanosine triphosphatase) activity of purified Ec-FtsZ protein was further analyzed by malachite green assay. Subsequently, the purified Ec-FtsZ protein was used to immunize rat subcutaneously for preparation of anti-Ec-FtsZ PcAb. The results of enzyme-linked immunosorbent assay (ELISA), Western blotting analysis and immunofluorescence assay showed that the titer of PcAb was 1:256 000, and PcAb exhibited a perfect antigenic specificity against purified and endogenous Ec-FtsZ protein. All these data indicated that the anti-Ec-FtsZ PcAb is successfully prepared, which can be used for further cellular function study and biochemical analysis of Ec-FtsZ protein in vivo.
Subject(s)
Animals , Rats , Antibodies , Antibody Specificity , Bacterial Proteins , Blotting, Western , Cytoskeletal Proteins , Enzyme-Linked Immunosorbent Assay , Escherichia coli , PlasmidsABSTRACT
Background & objectives: Botulism, a potentially fatal paralytic illness, is caused by the botulinum neurotoxins (BoNTs) secreted by Clostridium botulinum. It is an obligate anaerobic, Gram-positive, spore-forming bacterium. BoNTs are classified into seven serotypes based on the serological properties. Among these seven serotypes, A, B, E and, rarely, F are responsible for human botulism. The present study was undertaken to develop an enzyme-linked immunosorbent assay (ELISA)-based detection system for the detection of BoNT/E. Methods: The synthetic gene coding the light chain of BoNT serotype E (BoNT/E LC) was constructed using the polymerase chain reaction primer overlapping method, cloned into pQE30UA vector and then transformed into Escherichia coli M15 host cells. Recombinant protein expression was optimized using different concentrations of isopropyl-?-D-1-thiogalactopyranoside (IPTG), different temperature and the rBoNT/E LC protein was purified in native conditions using affinity column chromatography. The purified recombinant protein was checked by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and further confirmed by western blot and matrix-assisted laser desorption ionization-tandem time-of-flight (MALDI-TOF). Polyclonal antibodies were generated against rBoNT/E LC using Freund's adjuvant in BALB/c mice and rabbit. Sandwich ELISA was optimized for the detection of rBoNT/E LC and native crude BoNT/E, and food matrix interference was tested. The developed antibodies were further evaluated for their specificity/cross-reactivity with BoNT serotypes and other bacterial toxins. Results: BoNT/E LC was successfully cloned, and the maximum expression was achieved in 16 h of post-induction using 0.5 mM IPTG concentration at 25癈. Polyclonal antibodies were generated in BALB/c mice and rabbit and the antibody titre was raised up to 128,000 after the 2nd booster dose. The developed polyclonal antibodies were highly specific and sensitive with a detection limit about 50 ng/ml for rBoNT/E LC and 2.5�[3] MLD50 of native crude BoNT/E at a dilution of 1:3000 of mouse (capturing) and rabbit (revealing) antibodies. Further, different liquid, semisolid and solid food matrices were tested, and rBoNT/E LC was detected in almost all food samples, but different levels of interference were detected in different food matrices. Interpretation & conclusions: There is no immune detection system available commercially in India to detect botulism. The developed system might be useful for the detection of botulinum toxin in food and clinical samples. Further work is in progress.
ABSTRACT
In the present study, 2-methyl-4-( trifluoromethyl) thiaZole-5-carboxylic acid ( MTCA) was acted as hapten of thifluZamide to synthesiZe artificial antigens.Immunogen MTCA-bovine serum albumin ( BSA ) was synthesiZed by active ester method.Meanwhile, three coating antigens, MTCA-OVA-1, MTCA-OVA-2 and MTCA-OVA-3 were synthesiZed by active ester method, mixed anhydride method and N, N-carbonyldiimidaZole/4-dimethylaminopyridine ( CDI/DMAP ) method, respectively.Anti-thifluZamide polyclonal antibody with high specificity was obtained from the immuniZed mice, then indirect competitive enZyme linked immunosorbent assay ( ic-ELISA ) method for thifluZamide detection was developed by using MTCA-OVA-3 and polyclonal antibody.The linear detection range in ic-ELISA was 0.08-10 mg/L with an IC50 of 1.39 mg/L and a LOD (IC10) of 0.08 mg/L.The recoveries for spiked samples including tap water, lake water and wheat ranged from 72.0%-128.3% in ic-ELISA method.Good correlation (R2=0.9994) was obtained between the results of ic-ELISA and those of HPLC analysis.The proposed ic-ELSA was promising for rapid detection of thifluZamide in water and agricultural products.
ABSTRACT
Objective@#To construct the prokaryotic plasmid expressing the recombinant protein Coxsackie virus A6 VP1 or VP2 and prepare the antiserum of rabbit anti-CVA6 VP1 or anti-CVA6 VP2.@*Methods@#CVA6 VP1and VP2 gene fragments were amplified by reverse transcription PCR and inserted into the prokaryotic expression vectors. The recombinant plasmids were expressed in E. coli BL21 (DE3). After induction with Isopropyl β-D-Thiogalactoside (IPTG), the fusion proteins were obtained, and then purified by SDS-PAGE electrophoresis and gel extraction. The polyclonal antibodies were prepared by immunizing rabbits with the fusion proteins and analyzed with Western blot(WB) and indirect immunofluorescence assay(IFA).@*Results@#The prokaryotic expression vector of CVA6 VP1 or VP2 was confirmed by PCR, double enzyme digestion and sequencing. CVA6 VP1 and VP2 fusion proteins with high purity were obtained. WB and IFA were used to identify polyclonal antibodies.@*Conclusions@#The CVA6 VP1 and VP2 prokaryotic expression vectors were successfully constructed, and the recombinant CVA6 VP1 and VP2 proteins and their corresponding polyclonal antibodies were obtained.
ABSTRACT
To prepare and purify the rabbit anti-TgMIC16 polyclonal antibody, so as to apply it in subcellular localization.New Zealand white rabbits were immunized with purified recombinant TgMIC16 mixing with the same volume of Freund’s adjuvant for three times, respectively. The rabbit serum was collected on the 14th day after the last immunization. The polyclonal antibody in rabbit serum was purified with Protein A affinity purification column. ELISA and Western blotting were used to detect the antibody titer and specificity of polyclonal antibody. The polyclonal antibody was used to the localization of TgMIC16 by the immunofluorescence method.Indirect ELISA showed that the antibody titer was 1∶512 000. Western blotting showed that the recombinant TgMIC16 protein was recognized by the specific polyclonal antibody. IFA showed that TgMIC16 was located in the microneme of Toxoplasma gondii.The rabbit anti-TgMIC16 is prepared and purified, and successfully applied to immunofluorescence localization of TgMIC16 in T. gondii.
ABSTRACT
To clone,express and purify the E Protein and EDⅢ of Zika virus in E.coli and prepare two kinds of polyclonal antibodies,the virus was amplified by Vero E6 cell culture.Total RNA was extracted by RT-PCR and reverse transcribed into cDNA.The prokaryotic expression vectors pET32a/E and pET28a/EDⅢ were constructed by cDNA sequence of E and EDⅢ gene.Then,recombinant plasmids were transformed into E.coli BL21 and induced by IPTG,and purified by Ni+ column affinity chromatography.BALB/C mice were immunized with purified recombinant proteins.Antiserum was collected and titer was determined by indirect ELISA.Western blot was used to detect the specificity.Results showed that the recombinant proteins were successfully expressed and purified.The titer of the polyclonal antibodies both reached 1:409 600.Western Blot analysis showed that the polyclonal antibodies could specifically recognize the recombinant proteins.Thus,the specific polyclonal antibody were successfully prepared,laying a foundation for further study on the pathogenesis,detection methods and immune strategies of Zika virus.
ABSTRACT
Objective:The polyclonal antibody of aldosterone (ALD) for immunoassay was developed.And a chemiluminescence immunoassay (CLIA) for the determination of ALD in human blood was established.Methods:Aldosterone oxime was prepared by chemical modification and then conjugated with BSA to prepare immunogen.Rabbit anti ALD polyclonal antibody was prepared by immunizing rabbits with the ALD-BSA.The CLIA of ALD was performed using biotin streptavidin amplification system and competition method.Results:After identification,rabbit No.3 received the highest sensitivity to ALD antibody,and the 50％ binding inhibition (IC50) value for ALD concentration was 268 pg/ml.The measuring range of CLIA method using the antibody was 62.5-2 000 pg/ml.The assay sensitivity was 23.7 pg/ml.The intra-and inter-assay coefficients of variation were 6.9％-9.5％ and 8.5％-12.7％,respectively.Analytical recovery rate was in the range of 93.1％-104.1％.The correlation coefficient between measured and expected values were 0.996 after serial dilution.Compared with radioimmunoassay kit,the correlative equation was y =0.932x+4.596,the correlation coefficient was 0.948 (n =95).Conclusion:The result of methodological identification shows that it was in line with the basic requirements of clinical application.
ABSTRACT
To observe the immunogenicity of hPDGF-B immunogens that were synthesized with the fusional expression vector pET28-Trx and to test the suppressive effect of these specific antibodies induced by both of immunogens on proliferation of human HepG2 hepatoma cells. First, we chose 2 antigenic epitopes hPDGF-BΔ103-118aa and hPDGF-BΔ152-167aa from human PDGF-B and inserted these 2 coding regions into the empty vector plasmid pET28-Trx, separately. Second, mice were immunized with purified recombinant proteins to generate polyclonal antibody. Then we intraperitoneally injected mice bearing hepatoma 22 (H22) tumor cells to prepare antibody ascites. ELISA and Western blot were used to detect the titer and the utility of the antibody, respectively. Finally, HepG2 cells were exposed to PDGF-BB protein or anti-PDGF-B ascite antibody in different dilution concentrations groups and the proliferation of HepG2 cells was quantified by CCK8 assay. As the results, we identified mice that could produce high drop of neutralizing antibodies against hPDGF-B induced by both two recombinant proteins. Two anti-PDGF-B ascite antibodies could markedly inhibit the proliferation of HepG2 cells by blocking the stimulating effect of PDGF-BB protein. Our results suggest that Trx-PDGF-B recombinant protein as immunogen provides a new method for the preparation of PDGF-B vaccine, and also a new idea for the treatment of hepatocellular carcinoma in clinical practice.