• Journal of Microbiology and Biotechnology
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• v.29 no.2
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• pp.330-338
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• 2019

Chronic infection with intracellular Brucella abortus (B. abortus) in livestock remains as a major problem worldwide. Thus, the search for an ideal vaccine is still ongoing. In this study, we evaluated the protective efficacy of a combination of B. abortus recombinant proteins; superoxide dismutase (rSodC), riboflavin synthase subunit beta (rRibH), nucleoside diphosphate kinase (rNdk), 50S ribosomal protein (rL7/L12) and malate dehydrogenase (rMDH), cloned and expressed into a pMal vector system and $DH5{\alpha}$, respectively, and further purified and applied intraperitoneally into BALB/c mice. After first immunization and two boosters, mice were infected intraperitoneally (IP) with $5{\times}10^4CFU$ of virulent B. abortus 544. Spleens were harvested and bacterial loads were evaluated at two weeks post-infection. Results revealed that this combination showed significant reduction in bacterial colonization in the spleen with a log protection unit of 1.31, which is comparable to the average protection conferred by the widely used live attenuated vaccine RB51. Cytokine analysis exhibited enhancement of cell-mediated immune response as IFN-${\gamma}$ is significantly elevated while IL-10, which is considered beneficial to the pathogen's survival, was reduced compared to control group. Furthermore, both titers of IgG1 and IgG2a were significantly elevated at three and four-week time points from first immunization. In summary, our in vivo data revealed that vaccination with a combination of five different proteins conferred a heightened host response to Brucella infection through cell-mediated immunity which is desirable in the control of intracellular pathogens. Thus, this combination might be considered for further improvement as a potential candidate vaccine against Brucella infection.

• Korean Journal of Veterinary Research
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• v.55 no.3
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• pp.163-167
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• 2015

Canine parvovirus (CPV) is a major diarrhea-causing agent in puppies. Since CPV type 2 (CPV-2) emerged in 1978, new antigenic variants including CPV-2a, CPV-2b, and CPV-2c have been identified in many countries. Two puppies died suddenly at a veterinary clinic in Gyeonggi province, South Korea. Two viruses were isolated in A72 cells, confirmed as CPV strains based on a CPV rapid kit and an indirect fluorescence test and designated QIACP1403 and QIACP1404. The nucleotide sequences of complete VP2 genes of QIACP1403 and QIACP1404 were determined, and the corresponding amino acid sequences were deduced. Molecular analyses revealed that the QIACP1403 and QIACP1404 isolates were type CPV-2b. Several mutated amino acids were detected on VP2 gene residues of the two isolates. Phylogenetic analyses showed that the two isolates were most closely related to strain CPV-BM11, which was isolated from Chinese dogs in 2011. Our results suggest that these isolates may be a candidate for a vaccine to prevent CPV infection in dogs after conducting passages of the isolates in an in vitro culture system.

• Journal of Microbiology
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• v.40 no.1
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• pp.1-10
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• 2002

At the dose of 1000 p.f.u. per mouse,100% mortality occurred in mice inoculated with wild-type pseudorabies virus (PrV). In contrast, upon stable deletion of 10 bp nucleotides at the Bsrl site within the TK gene, PrV was rendered to be completely apathogenic. The deletion also caused the virus to be less capable of replicating in respiratory as well as in nervous system tissues. Although animals were exposed to high titers of TK-deleted PrVs, the virus failed to replicate to a high titer as compared to the pathogenic parental virus. In contrast to previous studies the deletion in the TK gene did not prevent the virus from establishing latency. Upon immunosuppression, the latent virus? however, reactivated but replicated at low titers. Interestingly, TK-deleted virus established latency and reactivation, that are occurred only in trigeminal ganglia and the cerebrums and no other tissues involved. Following reactivation, there was no indication of virus shedding in respiratory tissues as confirmed by virus isolation and polymerase chain reaction (PCR) technique targeting at the gB gene of PrV, The non-pathogenic virus with non-shedding characteristics, upon reactivation of the latent virus, would be the important feature of a live virus vaccine candidate.

• Fisheries and Aquatic Sciences
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• v.12 no.2
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• pp.98-103
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• 2009

The potential utility of the rockbream (Oplegnathus fasciatus) $\beta$-actin 5'-upstream sequence as a regulatory element for DNA vaccination was evaluated based on in vitro and in vivo heterologous expression assays. In the in vitro transfection experiment, the efficacy of the rockbream $\beta$-actin promoter to drive the expression of a downstream lacZ gene was significantly higher (more than fourfold) than that of the human cytomegalovirus (hCMV) promoter in two fish cell lines (grunt Haemulon plumierii fin and bluegill Lepomis macrochirus fry cell lines). In contrast, the functional activity of the rockbream $\beta$-actin promoter was hardly detectable in a mammalian mouse embryonic fibroblast cell line. Rockbream skeletal muscles injected in vivo with a GFP reporter construct driven by the $\beta$-actin promoter displayed the significantly higher expression of a GFP protein (more than threefold) than did those injected with hCMV promoter driven construct. Data from this study suggest that the homologous rockbream $\beta$-actin promoter could be used as a potential regulator for DNA vaccination in this species.

• BMB Reports
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• v.40 no.6
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• pp.1002-1008
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• 2007

PreS domain of Hepatitis B virus (HBV) surface antigen is a good candidate for an effective vaccine as it activates both B and T cells besides binding to hepatocytes. This report deals with overexpression and purification of adr subtype of surface antigen that is more prevalent in Pakistan. PreS region, comprising 119 aa preS1 region plus a 55 aa preS2 region plus 11 aa from the N-terminal S region, was inserted in pET21a+ vector, cloned in E. coli $DH5\alpha$ cells and expressed in E. coli BL21 codon+ cells. The conditions for over expression were optimized using different concentrations of IPTG (0.01-5 mM), and incubating the cells at different temperatures (23-$41^{\circ}C$) for different durations (0-6 h). The cells were grown under the given optimized conditions (0.5 mM IPTG concentration at $37^{\circ}C$ for 4 h), lysed by sonication and the protein was purified by ion exchange chromatography. On the average, 24.5 mg of recombinant protein was purified per liter of culture. The purified protein was later lyophilized and stored at $-80^{\circ}C$.

• Journal of Microbiology and Biotechnology
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• v.2 no.3
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• pp.174-182
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• 1992

The hemagglutinin-esterase glycoprotein (HE) gene of bovine coronavirus, coupled with a simian virus 40 early promoter and polyadenylation signal, was inserted into a human adenovirus transfer vector. The transfer vector was used to co-transfect 293 cells along with adenovirus genomic DNA. The hemagglutinin-esterase transcription unit was rescued into the adenovirus genome by homologous in vivo DNA recombination between the vector plasmid DNA and the adenovirus genomic DNA, and a recombinant adenovirus was isolated by several rounds of plaque assays. Thus the recombinant adenovirus carries the hemagglutinin-esterase gene in the early transcription region 3 (E3) of the adenovirus genome in the parallel orientation to the E3 transcription. The recombinant adenovirus synthesized the HE polypeptide in HeLa cells as demonstrated by immunoprecipitation with anti-coronavirus rabbit antisera. The recombinant HE polypeptide could be labelled by $[^3H]$glucosamine, demonstrating that the recombinant HE was glycosylated. Cells expressing the HE polypeptide exhibited hemadsorption activity when incubated with mouse erythrocytes. The HE was transported to the plasma membrane as shown by the cell surface immunofluorescence, indicating that the recombinant HE polypeptide retained its biological activities. Potential for the use of infectious recombinant adenovirus as a live virus-vectored vaccine candidate for bovine coronavirus disease is discussed.

• Korean Journal of Veterinary Research
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• v.57 no.1
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• pp.9-15
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• 2017

To construct a novel vaccine candidate against bovine enterotoxigenic Escherichia coli (ETEC), FanC, the major subunit of K99 fimbriae adhesion, was inserted into secretion plasmid pYA3560 containing a ${\beta}-lactamase$ secretion system. This was then transformed into ${\Delta}asd$ ${\Delta}crp$ Salmonella (S.) Typhimurium and designated as JOL950. Secretion of recombinant fanC fimbrial antigens was confirmed by immunoblot analysis. Groups of mice were inoculated with single or double doses of JOL950. Another group was used as a negative control. Compared to control mice, all immunized mice had significantly higher levels (p < 0.05) of serum immunoglobulin (Ig)G, and secretory IgA against FanC. The IgG2a and IgG1 titer assays revealed that immunization highly induced IgG2a compared to that of IgG1, indicating that T helper-1- related cell-mediated immune responses may be elicited by JOL950. The results show that both systemic and mucosal immunities against selected fimbrial antigens of bovine ETEC expressed by a live attenuated S. Typhimurium strain are prominently produced in mice immunized with JOL950 via an oral route.

• Biomolecules & Therapeutics
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• v.20 no.3
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• pp.320-325
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• 2012

Rotavirus and hepatitis A virus (HAV) spread by the fecal-oral route and infections are important in public health, especially in developing countries. Here, two antigenic epitopes of the HAV polyprotein, domain 2 (D2) and domain 3 (D3), were recombined with rotavirus VP7, generating D2/VP7 and D3/VP7, cloned in a baculovirus expression system, and expressed in Spodoptera frugiperda 9 (Sf9) insect cells. All were highly expressed, with peak expression 2 days post-infection. Western blotting and ELISA revealed that two chimeric proteins were antigenic, but only D2/VP7 was immunogenic and elicited neutralizing antibody responses against rotavirus and HAV by neutralization assay, implicating D2/VP7 as a multivalent subunit-vaccine Candidate for preventing both rotavirus and HAV infections.

• Parasites, Hosts and Diseases
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• v.62 no.1
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• pp.75-84
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• 2024

Ancylostoma ceylanicum is a zoonotic soil-derived nematode that parasitizes the intestines of humans and animals (dogs and cats), leading to malnutrition and iron-deficiency anemia. Helminth parasites secrete calreticulin (CRT), which regulates or blocks the host's immune response. However, no data on A. ceylanicum calreticulin (Ace-CRT) are available. We investigated the biological function of recombinant Ace-CRT (rAce-CRT). rAce-CRT showed reliable antigenicity and stimulated the proliferation of mouse splenocytes and canine peripheral blood mononuclear cells. Quantitative reverse-transcription PCR assays revealed that rAce-CRT primarily promoted the expression of T helper 2 cytokines, particularly IL-13, in canine peripheral blood lymphocytes. rAce-CRT inhibited complement-mediated sheep erythrocyte hemolysis in vitro. Our findings indicate that Ace-CRT plays an immunomodulatory role and may be a promising candidate molecule for a hookworm vaccine.

• Parasites, Hosts and Diseases
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• v.30 no.2
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• pp.133-140
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• 1992

Theileria sergenti were isolated from infected erythrocytes by hypotonic Iysis, and soluble meroBoite antigens were purified by sonication and differential centrifugation. The preparation contained 29, 34, 35 and 105 kD immuno-dominant polypeptides. The soluble antigens (0.5 mg/ml) were prepared and fortified with Freund's adjuvant. Five month old naive Korean calves were subcutaneously inoculated with the preparation and a booster dose was administered 4 weeks later Nine weeks after the booster dose, vaccinates and controls were challenged with a homologous stabilate (5.6×106 RBC/dose, 40% Parasitemia). All animals were monitored for hematocrit, total erythrocyte count, parasitemia and for the specific antibody by Western immuno- blot (WB) and indirect immuno-auorescent antibody(IFA) test. By 18 weeks after vaccination (6 weeks after the challenge), vaccinated cattle had an average IFA titer of 1 : 10,240 compared with 1 : 1,280 of the controls. The vaccinates showed ne91igib1e change in hematocrit and total RBC count whereas control animals showed significant (P<0.05) hematological chanties and associated anemia. After vaccination and challenge, the antibody responses demonstrated that vaccination had induced significant production of antibody to the 29 and 35 kD polypeptides. The latter polypeptide was much more strongly recognized by the vaccinated animals, and thus it may be a potential candidate for the vaccine.