BACKGROUND: The veterinary Rabies vaccine was produced using BHK-21 cells and PV strain. Although various protocols have been suggested for virus purification, they have an adverse effect on the final production and require further optimization.OBJECTIVES: The present study aimed to optimize the concentration and purification of the virus for rabies vaccine production.METHODS: First of all, the Pasteur virus strain (PV) was cultured by using BHK 21 cells with DMEM media contain bovine fetal serum (7 %) for five days. Subsequently, the virus purification was done via tangential flow filtration (TFF) system. The quality of purifying viruses was an assessment with titration and SDS-PAGE. Secondly, the virus inactivation was optimized using Minitab software based on three factors, namely time, temperature, and concentration. Afterwards, the inactivity of the samples was tested on mice. Finally, the virus potency was evaluated by the National Institute of Health (NIH) method.RESULTS: The viral titration test in TFF samples revealed that viral titer increased in comparison with the control group (P<0.05). The SDS-PAGE analysis of the purified and concentrated samples showed that the purified virus via TFF had a higher purity compared to the not-concentrated samples. Moreover, the NIH test indicated a 10-fold increase in potency result in the TFF group.CONCLUSIONS: The present study implied that the TFF method is highly suitable for condensation and purification of a high volume of viral fluid and could be applied on an industrial scale to increase the potency of the vaccine produced.

Seven hybridomas that secreted monoclonal antibodies (MAB) against the peplomer protein and one that secreted MAB against the nucleocapsid protein of Berne virus (proposed family Toroviridae) were isolated. All MAB directed against the peplomer protein neutralized virus infectivity and, with the exception of MAB 6A7, inhibited each other's binding in competition assays. Neutralization of Berne virus infectivity was potentiated when some MAB were used in pairs. The antibodies have been used to localize toroviral proteins in infected cells; use of antipeplomer MAB 6B10 yielded a diffuse intracytoplasmic immunofluorescence, whereas the antinucleocapsid MAB 1F1 detected antigen in the intra- and perinuclear compartments. By use of radioimmune precipitation, protein A of Staphylococcus aureus was found to bind directly to the nucleocapsid polypeptide, without the requirement for specific antibody. Using fluorescein isothiocyanate-conjugated protein A, the intranuclear accumulation of the nucleoprotein of Berne virus was confirmed by results of immunofluorescence.

Bovine fibroblast interferon (BoF-IFN), produced in primary bovine embryonic kidney cell cultures after priming and infection with bluetongue virus, was purified by controlled pore glass (CPG) chromatography to a specific activity of 10(6) U/mg of protein, with 40% recovery of the original activity. The crude IFN was concentrated more than sevenfold during purification. This proved to be a relatively simple, practical method of obtaining sufficient quantities of partially purified natural BoF-IFN for further studies. The CPG-purified BoF-IFN was further concentrated by sequential ultrafiltration and was analyzed by sodium dodecyl sulfate/polyacrylamide-gel electrophoresis (SDS-PAGE). Interferon, recovered from denaturing conditions either by dialysis against phosphate-buffered saline solution or by dilution in cell culture medium containing 10% fetal bovine serum, migrated as a single stainable protein with molecular weight of 21,000 on analytic SDS-PAGE gels. Recovered IFN activity from preparative SDS-PAGE totalled 8.7% of that applied. Attempts to further purify CPG-purified BoF-IFN by zinc chelate affinity chromatography were unsuccessful.

Ovine interferon-tau (oIFN-τ) is a newly discovered type I interferon. This study used biochemical techniques to transform the oIFN-τ gene into Escherichia coli to obtain the mass and soluble expression of the recombinant protein.

Ovine interferon-tau (oIFN-τ) is a newly discovered type I interferon. This study used biochemical techniques to transform the oIFN-τ gene into Escherichia coli to obtain the mass and soluble expression of the recombinant protein. First, total RNA was extracted from fresh sheep embryonic tissues with TRIzol reagent and then used as a template to reverse transcribe and amplify the mature oIFN-τ gene with RT-PCR. The amplified product was next digested with the HindIII and XhoI restriction enzymes and inserted into the pET-32a(+) vector to construct the prokaryotic expression plasmid. The corrected in-frame recombinant plasmid, pET-32a(+)-oIFN-τ, was transformed into E. coli Rosetta (DE3) competent cells. After induction with isopropyl-beta-D-thiogalactopyranoside (IPTG), the recombinant protein was detected in bacteria. Finally, the bacteria were lysed by sonication, and the recombinant protein was purified by nickel affinity chromatography and DEAE anion exchange chromatography. The protein was confirmed to be oIFN-τ, which mainly existed in the soluble lysate fraction, as proven by SDS-PAGE and Western blot assays. Purified IFN-τ exists mostly in a soluble form, and its anti-vesicular stomatitis virus (VSV) activity reached 7.08×10(6)IU/mL.

Alpha toxin of S aureus has cytolytic activity respectively. This antigen has been received the most attention since it is a major virulence factor in pathogenesis of staphylococcal mastitis. Thus, alpha toxin has been focused as potential candidate ofvaccine tominimize mastitis in cows. the purpose of this study was to develop a simple, efficient production and purification methods of sufficient amount of alpha toxin antigen from S aureus. Alpha toxin production measured by hemolytic activity was the highest at 18 hrs postinoculation in yeast extract culture medium supplemented with thiamine, nicotinic acid and casamino acid. Alpha toxin was purifed by ammonium sulfate precipitation (65%) and ultrafiltration. Molecular weight of the toxin was 33 kDa in the analysis with SDS-PAGE. Conclusionally, when alpha toxin was included in the vaccine, the optimal harvest time of alpha toxin was at 18 hrs after inoculation in yeast extract medium supplemented with thiamine and nicotinic acid.

Fifty serum samples from dogs with clinical signs of hypothyroidism and autoantibodies (AA) to thyroglobulin (Tg), thyroxine, or triiodothyronine were screened for AA to thyroid peroxidase (TPO). Thyroid peroxidase is the antigen against which microsomal AA are formed in human beings with lymphocytic thyroiditis. The TPO was isolated from canine thyroid tissue, using a modification of the procedure for purifying porcine TPO. The enzyme was solubilized from the membrane, using a deoxycholate-trypsin solution, followed by ammonium sulfate precipitation and diethylaminoethyl Sephadex chromatography. Activity of TPO was determined, using an iodide oxidation assay and a guaiacol assay. A monoclonal antibody to canine Tg, coupled to an immunoaffinity column, was used to eliminate the contaminating Tg from the TPO preparation. Using the TPO preparation as an antigen, an ELISA was performed on 10 serum samples and immunoblot assays were performed on 50 canine sera. Autoantibodies to TPO were not found in any of the sera. Assays also were performed, using purified porcine and human TPO and evidence of cross-reactivity with canine TPO was not identified. The absence of AA to TPO in dogs suggests a different pathogenesis for autoimmune thyroid disease in dogs than that hypothesized for lymphocytic thyroiditis in human beings.

An efficient, single-step method for purification of the 110-kilodalton (kDa) hemolysin of Actinobacillus pleuropneumoniae was developed. An immunoaffinity column was made by cross-linking murine monoclonal antibody 8C2 to the 110-kDa hemolysin of A pleuropneumoniae strain J45 serotype 5 to protein A-agarose beads. Purified hemolysin with high hemolytic activity was obtained after washing the column with phosphate-buffered saline solution, and eluting the hemolysin with 50 mM diethylamine, pH 11.0. The same column was also used to purify the hemolysin from A pleuropneumoniae strain 4074 serotype 1. The purification procedure could be completed within 5 hours, and almost 50% of the total hemolytic activity and hemolysin protein was recovered in pure form.

Lipopolysaccharide (LPS) fractions were obtained from smooth cultures of Brucella abortus strains 2308 and S-19 by butanol extraction procedures. The LPS from the initial butanol extraction contained 10 to 15% protein and was reduced to less than 1% protein by treatment with proteinase K. The LPS fractions were identified and characterized on the basis of the chemical analysis, sodium dodecyl sulfate gel electrophoresis, cesium chloride gradients, electron microscopy, and gel immunodiffusion. Results indicated that the butanol procedure is a reliable method in the extraction of LPS from Brucella abortus cells. Proteinase K-treated LPS containing less than 1% protein from strain 2308 was used to vaccinate BALB/cByJ mice. Immune and protective criteria for vaccinated and nonvaccinated mice were increased immunoglobulin (IgG and IgM) titers in sera of prechallenge-exposed mice, reduced colony-forming units/spleen, and splenomegaly in post-challenge-exposed mice. Results indicated that proteinase K-treated LPS was immunuogenic as well as protective for mice.

Bovine fibroblast interferon (BoF-IFN), produced in bovine embryonic kidney cell cultures by priming and infection with bluetongue virus, was partially purified by controlled pore glass chromatography. The partially purified B0F-IFN then was subjected to beaded agarose affinity chromatography. The IFN eluted by affinity chromatography in 2 distinct fractions-1 after the addition of 1M NaCl and the other one after the addition of 1.5M NaCl containing 50% ethylene glycol. Analysis of fractions by sodium dodecyl sulfate/polyacrylamide-gel electrophoresis revealed a broad molecular weight range (14,900 to 27,900) for the IFN eluted by 1M NaCl, and 2 discrete molecular weight ranges (16,000 to 19,500 and 28,300 to 34,000) for IFN eluted by 1.5M NaCl containing 50% ethylene glycol. The specific activity of the IFN eluted with 1.5M NaCl containing ethylene glycol was 2.85 X 10(6) U/mg of protein, compared with 5.7 X 10(5) U/mg of protein in the controlled pore glass-purified IFN.