• Journal of Microbiology
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• v.45 no.2
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• pp.179-184
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• 2007

Pasteurella multocida, a Gram-negative facultative anaerobic bacterium, is a causative animal pathogen in porcine atrophic rhinitis and avian fowl cholera. For the development of recombinant subunit vaccine against P. multocida, we cloned and analyzed the gene for outer membrane protein H (ompH) from a native strain of Pasteurella multocida in Korea. The OmpH had significant similarity in both primary and secondary structure with those of other serotypes. The full-length, and three short fragments of ompH were expressed in E. coli and the recombinant OmpH proteins were purified, respectively. The recombinant OmpH proteins were antigenic and detectable with antisera produced by either immunization of commercial vaccine for respiratory disease or formalin-killed cell. Antibodies raised against the full-length OmpH provided strong protection against P. multocida, however, three short fragments of recombinant OmpHs, respectively, showed slightly lower protection in mice challenge. The recombinant OmpH might be a useful vaccine candidate antigen for P. multocida.

• Journal of Photoscience
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• v.9 no.2
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• pp.323-325
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• 2002

Bacillus Anthracis is the causative agent of anthrax. The major virulence factors are a poly-D glutamic acid capsule and three-protein component exotoxin, which is collectively known as anthrax toxin, protective antigen (PA, 83 kDa), lethal factor (LF, 90 kDa), and edema factor (EF, 89 kDa). These three proteins individually have no known toxic activities, but in combination with PA form two toxins (lethal toxin and edema toxin), causing different pathogenic responses in animals and cultured cells. However, it remains to be elucidated for pathogenic mechanism of anthrax toxin. In this study, we constructed toxin component in bacterial overexpression system and purified the native toxin from Bacillus anthracis delta sterne F32 using FPLC system. Recombinant toxin showed high homogeneity and rapid purification processes. Also, this recombinant toxin was comparable to B. anthracis native toxin in terms of cytotoxic effects on cultured cell lines.

• IMMUNE NETWORK
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• v.9 no.5
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• pp.169-178
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• 2009

DNA immunization induces B and T cell responses to various pathogens and tumors. However, these responses are known to be relatively weak and often transient. Thus, novel strategies are necessary for enhancing immune responses induced by DNA immunization. Here, we demonstrated that co-immunization of influenza virus nucleoprotein (NP) gene significantly enhances humoral and cell-mediated responses to codelivered antigens in mice. We also found that NP DNA coimmunization augments in vivo proliferation of adoptively transferred antigen-specific CD4 and CD8 T cells, which enhanced protective immunity against tumor challenge. Our results suggest that NP DNA can serve as a novel genetic adjuvant in cocktail DNA vaccination.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.4
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• pp.710-718
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• 2011

Edema factor(EF) is a portion of anthrax toxin which produces edema when combined with protective antigen. This paper describes about technique for cloning, expression, purification and activity test of EF. Using the E. coli expression system, we could make recombinant EF protein although it's origin is Bacillus anthracis. And also we could culture massively and purify highly pure protein. Finally we confirm a enzyme activity of purified EF to increase intracellular cAMP level. Through establishing this technique, it can be possible to research about EF in depth and apply to expression and purification of many other protein in biology.

• Journal of Microbiology and Biotechnology
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• v.19 no.11
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• pp.1475-1481
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• 2009

Anthrax is a zoonotic disease caused by Bacillus anthracis, and well recognized as a potential agent for bioterrorism. B. anthracis can be identified by detecting the virulence factors genes located on two plasmids, pXO1 and pXO2. The aim of the present study was to determine the presence of virulence genes in 27 isolates of B. anthracis isolated from clinical and environmental samples. For this purpose, multiplex PCR and DNA probes were designed to detect protective antigen (pag), edema factor (cya), lethal factor (lef), and capsule (cap) genes. Our results indicated that all the isolates contained all the above virulence genes, suggesting that the isolates were virulent. To the best our knowledge, this is the first study about the determination of virulence marker genes in clinical and environmental isolates of B. anthracis using multiplex PCR and DNA probes in India. We suggest that the above methods can be useful in specific identification of virulent B. anthracis in clinical and environmental samples.

• Korean Journal of Veterinary Service
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• v.33 no.2
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• pp.173-176
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• 2010

Here, we report the suitability of using a resin-type chitosan formulae as a sustained-releasing form adjuvant in comparison with commercially well-known Freund's adjuvants. To induce the immunological responses, N-terminal region of Pasteurella multocida toxin was used as an antigen, which was found to be protective immunogen against P. multocida infection. Mice immunized with chitosan resin formulae showed statistically significant antibody induction (P<0.001) as much as that of Freund’s adjuvants. As a result, the resin-type sustained-releasing form chitosan formulae is thought to be a good candidate for a new type adjuvant.

• Parasites, Hosts and Diseases
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• v.61 no.3
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• pp.231-239
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• 2023

Toxoplasma gondii is an intracellular parasitic organism affecting all warm-blooded vertebrates. Due to the unavailability of commercialized human T. gondii vaccine, many studies have been reported investigating the protective efficacy of pre-clinical T. gondii vaccines expressing diverse antigens. Careful antigen selection and implementing multifarious immunization strategies could enhance protection against toxoplasmosis in animal models. Although none of the available vaccines could remove the tissue-dwelling parasites from the host organism, findings from these pre-clinical toxoplasmosis vaccine studies highlighted their developmental potential and provided insights into rational vaccine design. We herein explored the progress of T. gondii vaccine development using DNA, protein subunit, and virus-like particle vaccine platforms. Specifically, we summarized the findings from the pre-clinical toxoplasmosis vaccine studies involving T. gondii challenge infection in mice published in the past 5 years.

• IMMUNE NETWORK
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• v.22 no.6
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• pp.46.1-46.25
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• 2022

T-helper-17 (Th17) cells and related IL-17-producing (type17) lymphocytes are abundant at the epithelial barrier. In response to bacterial and fungal infection, the signature cytokines IL-17A/F and IL-22 mediate the antimicrobial immune response and contribute to wound healing of injured tissues. Despite their protective function, type17 lymphocytes are also responsible for various chronic inflammatory disorders, including inflammatory bowel disease (IBD) and colitis associated cancer (CAC). A deeper understanding of type17 regulatory mechanisms could ultimately lead to the discovery of therapeutic strategies for the treatment of chronic inflammatory disorders and the prevention of cancer. In this review, we discuss the current understanding of the development and function of type17 immune cells at the intestinal barrier, focusing on the impact of microbiota-immune interactions on intestinal barrier homeostasis and disease etiology.

• Tuberculosis and Respiratory Diseases
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• v.57 no.2
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• pp.125-131
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• 2004

Tuberculosis (TB) remains an enormous global health problem, and a new vaccine against TB more potent than the current inadequate BCG vaccine is urgently needed. We constructed three recombinant Mycobacterium bovis BCG (rBCG) strains over-expressing antigen (Ag) 85A, Ag85B, or both of M. tuberculosis using their own promoter and secretory sequence, or hsp60 promoter. SDS-PAGE analysis of rBCG proteins showed overexpression of Ag85A and Ag85B proteins in higher level than of those in their parental strain of BCG. In addition, rBCG(rBCG/B.FA) over-expressing Ag85A and Ag85B induced strong IFN-${\gamma}$ production in splenocytes. However, there was no significant difference in protective efficacy between rBCG and their parental BCG strain. In this study, therefore, rBCG over-expressing Ag85A, Ag85B, or both failed to show enhanced protection against M. tuberculosis infection in a mouse model.

• Korean Journal of Microbiology
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• v.42 no.3
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• pp.195-198
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• 2006

Lethal toxin is a critical virulence factor of anthrax. It is composed two protein: protective antigen (PA) and lethal factor (LF). PA binds to specific cell surface receptors and, forms a membrane channel that mediates entry of LF into the cell. LF is a zinc-dependent metalloprotease, which cleaves MKKs [MAPK (mitogen-activated protein kinase) kinases] at peptide bonds very close to their N-termini. In this study, we suggest application of cell-based assays in the early phase of drug discovery, with a particular focus on the use of yeast cells. We constructed MEK1 expression system in yeast to determine LF activity and approached cell-based assay system to screen inhibitors, in which the results covering the construction of LF-substrate in yeast expression vector, expression, and LF-mediated proteolysis of substrate were described. These results could provided the basic steps in design of cell-based assay system with the high efficiency, rapidly and easy way to screening of inhibitors.