• Journal of Microbiology and Biotechnology
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• v.11 no.6
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• pp.946-950
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• 2001

Slow-growing pathogenic mycobacterium species, including Mycobacterium bovis BCG, secrete a large amount of glutamine synthetase into culture media. Extracellular and intracellular glutamine synthetases were purified from M. bovis BCG. While the native molecular weights of both glutamine synthetases were estimated to be 370.2 kDa, those of the subunits were 61.7 kDa, indicating that the native forms were composed of 6 subunits. The enzymes showed a hhigh thermal stability and high degree of sequence similarity with the glutamine synthetase from M. tuberculosis in the N-terminal amino acid sequence. Western blotting analysis indicated that the antibodies prepared against both the extracellular and intracellular enzymes exhibited common antigen determinants.

• 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.

• Tuberculosis and Respiratory Diseases
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• v.75 no.3
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• pp.125-127
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• 2013

In this paper, we describe 72-year-old female patient without evidence of malignant disease presented with significantly elevated serum carbohydrate antigen (CA) 19-9 levels by respiratory infections. She was diagnosed with respiratory infections due to Mycobacterium avium complex and Pseudomonas aeruginosa. The serum CA 19-9 levels remarkably increased (1,453-5,300 U/mL; reference range, <37 U/mL) by respiratory infection and abruptly decreased (357-534 U/mL) whenever infection was controlled by specific treatments. This case suggests that serum CA 19-9 levels may be used as a diagnostic marker to indicate new or resistant infections to previous antibiotics in chronic lung diseases without significant changes in chest X-ray findings.

• Parasites, Hosts and Diseases
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• v.50 no.4
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• pp.281-286
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• 2012

Helminthic infections afflict over 1.5 billion people worldwide, while Mycobacterium tuberculosis infects one third of the world's population, resulting in 2 million deaths per year. Although tuberculosis and helminthic infections coexist in many parts of the world, and it has been demonstrated that the T-helper 2 and T-regulatory cell responses elicited by helminths can affect the ability of the host to control mycobacterial infection, it is still unclear whether helminth infections in fact affect tuberculosis disease. In this review article, current progress in the knowledge about the immunomodulation induced by helminths to diminish the protective immune responses to bacille Calmette-Guerin vaccination is reviewed, and the knowledge about the types of immune responses modulated by helminths and the consequences for tuberculosis are summarized. In addition, recent data supporting the significant reduction of both M. tuberculosis antigen-specific Toll-like receptor (TLR) 2 and TLR9 expression, and pro-inflammatory cytokine responses to TLR2 and TLR9 ligands in individuals with M. tuberculosis and helminth co-infection were discussed. This examination will allow to improve understanding of the immune responses to mycobacterial infection and also be of great relevance in combating human tuberculosis.

• The Journal of the Korean Society for Microbiology
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• v.16 no.1
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• pp.39-48
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• 1981

A direct complement fixation test supplemented with procomplementary porcine serum was studied using anticomplementary human, rabbit and bovine serum against Mycobacterium tuberculosis. Procomplementary activity of porcine serum varied with porcine individual and affected by anticomplementary antiserum. The procomplementary titre of porcine serum against rabbit, human and bovine serum ranged from 1:5 to 1:40. By means of complement fixation test supplemented by porcine serum, the specific complement-fixing antibody to both tuberculopolysaccharide and/or tuberculoprotein antigen was readily differentiated from the anticomplementary antibody titre.

• Biomedical Science Letters
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• v.19 no.2
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• pp.90-97
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• 2013

The tuberculin skin test (TST) and interferon gamma (IFN-${\gamma}$) release assay (IGRA) have been widely used for diagnosis of latent tuberculosis infection (LTBI). In order to overcome limitations of current LTBI diagnostic methods, the development of a novel molecular assay which is able to measure the IFN-${\gamma}$ messenger RNA (mRNA) expression level after stimulation with Mycobacterium tuberculosis (MTB) specific antigen was recently developed. The ability of a molecular assay to detect MTB infection was similar to commercial IGRA however, the optimal incubation time for stimulating IFN-${\gamma}$ was not yet established. Therefore, in this study the direct comparisons of MTB Ag stimulation times (4 and 24 hrs) were performed for diagnosis of MTB infection. Data showed that the coincident rate between QFT-GIT IFN-${\gamma}$ ELISA and IFN-${\gamma}$ RT-PCR (4 hrs) was 88.35% and that of QFT-GIT and IFN-${\gamma}$ RT-PCR (24 hrs) was 70.85%. Based on a receiver operating characteristic (ROC) curve, the 4 hrs-MTB specific Ag stimulation time for IFN-${\gamma}$ RT-PCR had the significant P value, 95% CI value, and AUC (P < 0.0001, 95% CI=0.82 to 1.02, and AUC=0.9214) in comparison with 24 hrs-MTB specific Ag stimulation time (P = 0.009, 95% CI=0.06 to 0.94, and AUC=0.7711). These results show that 4-hr was the most optimal MTB Ag stimulation time for performing IFN-${\gamma}$ RT-PCR. Although semi-quantitative RT-PCR had a few analytical limitations, it might be useful as an alternative molecular diagnostic method for detecting MTB infection.

• Tuberculosis and Respiratory Diseases
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• v.80 no.1
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• pp.77-82
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• 2017

Background: Delayed hypersensitivity plays a large role in the pathogenesis of tuberculous pleural effusion (TPE). Macrophages infected with live Mycobacterium tuberculosis (MTB) increase the levels of adenosine deaminase2 (ADA2) in the pleural fluid of TPE patients. However, it is as yet unclear whether ADA2 can be produced by macrophages when challenged with MTB antigens alone. This study therefore evaluated the levels of ADA2 mRNA expression, using monocyte-derived macrophages (MDMs) stimulated with MTB antigens. Methods: Purified monocytes from the peripheral blood mononuclear cells of healthy volunteers were differentiated into macrophages using granulocyte-macrophage colony-stimulating factor (GM-CSF) or macrophage colony-stimulating factor (M-CSF). The MDMs were stimulated with early secretory antigenic target protein 6 (ESAT6) and culture filtrate protein 10 (CFP10). The mRNA expression levels for the cat eye syndrome chromosome region, candidate 1 (CECR1) gene encoding ADA2 were then measured. Results: CECR1 mRNA expression levels were significantly higher in MDMs stimulated with ESAT6 and CFP10, than in the unstimulated MDMs. When stimulated with ESAT6, M-CSF-treated MDMs showed more pronounced CECR1 mRNA expression than GM-CSF-treated MDMs. Interferon-${\gamma}$ decreased the ESAT6- and CFP10-induced CECR1 mRNA expression in MDMs. CECR1 mRNA expression levels were positively correlated with mRNA expression of tumor necrosis factor ${\alpha}$ and interleukin 10, respectively. Conclusion: ADA2 mRNA expression increased when MDMs were stimulated with MTB antigens alone. This partly indicates that pleural fluid ADA levels could increase in patients with culture-negative TPE. Our results may be helpful in improving the understanding of TPE pathogenesis.

• IMMUNE NETWORK
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• v.11 no.2
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• pp.123-133
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• 2011

Background: Mycobacterium tuberculosis (Mtb) heparin binding hemagglutinin (HBHA) is an Ag known to evoke effective host immune responses during tuberculosis infection. However, the molecular basis of the host immune response to HBHA has not been fully characterized. In this study, we examined the molecular mechanisms by which HBHA can induce the expression of proinflammatory cytokines in macrophages. Methods: HBHA-induced mRNA and protein levels of proinflammatory cytokines were determined in bone marrow-derived macrophages (BMDMs) using RT-PCR and ELISA analysis. The roles of intracellular signaling pathways for NF-${\kappa}B$, PI3-K/Akt, and MAPKs were investigated in macrophage proinflammatory responses after stimulation with HBHA. Results: HBHA robustly activated the expression of mRNA and protein of both TNF-${\alpha}$ and IL-6, and induced phosphorylation of NF-${\kappa}B$, Akt, and MAPKs in BMDMs. Both TNF-${\alpha}$ and IL-6 production by HBHA was regulated by the NF-${\kappa}B$, PI3-K, and MAPK pathways. Furthermore, PI3-K activity was required for the HBHA-induced activation of ERK1/2 and p38 MAPK, but not JNK, pathways. Conclusion: These data suggest that mycobacterial HBHA significantly induces proinflammatory responses through crosstalk between the PI3-K and MAPK pathways in macrophages.

• Tuberculosis and Respiratory Diseases
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• v.48 no.3
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• pp.315-323
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• 2000

Background : An immunochromatographic assay (ICT Diagnostics) which facilitates the diagnosis of tuberculosis(TB) by detecting serum antibodies mainly directed against specific 38KDa of Mycobacterium tuberculosis has come into the market. The test consists of a cardboard folding device containing nitrocellulose strip and absorbent pads. The whole procedure is completed within 15 min and does not require any additional equipment. The test has been reported to be sensitive and specific in diagnosing active TB. Thus the test had been evaluated with sera from TB patients and TB-free subjects. Method : Sera from patients with active pulmonary tuberculosis(40 sputum positives for Mycobacterium tuberculosis, 79 sputum negatives, and 3 extrapulmonary tuberculosis) were obtained from the Double-Cross Chest Clinic of the Korean National Tuberculosis Association (KNTA) in Seoul. The control group consisted of TB-free 68 subjects(21 children under 7 years old and 47 healthy staff members of KNTA). Results : Nine out of 68(13.2%) TB-free controls had positive antibody response. Total 106 of 122(86.9%) radiologically active patients had positive antibodies while 16 (13.1%) showed negative reaction. Antibody was detected in 38 of 40(95.0%) sputum positive patients and 68 of 82(82.9%) sputum negative patients who were under the antituberculosis chemotherapy. The sensitivity and specificity were all 87% and the positive predictive value was 92.2% while the negative predictive value was 78.7%, when the prevalence of TB in the sample was 64.2%. Our results clearly show that the detection of antibodies which mainly react with the 38KDa antigen of M. tuberculosis is not suitable as the first-line method of diagnosis but considered only as an adjunctive test to standard techniques of tuberculosis diagnosis. when considering its high false positivity.

• Tuberculosis and Respiratory Diseases
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• v.47 no.1
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• pp.13-25
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• 1999

Background: Ineffective cell-mediated immune response in human tuberculosis is associated with a depressed Thl cytokine response and reduced production of IFN-$\gamma$. Most persons infected with Mycobacterium tuberculosis are healthy tuberculin reactors with protective immunity, but a minority with ineffective immunity develop extensive pulmonary tuberculosis. The cell-mediated immune response is an important aspect of host resistance to mycobacterial infection and is believed to be tightly regulated by a balance between Th1 cytokines including IFN-$\gamma$, IL-12, IL-18, regulated on activation, normal T cell expressed and secreted (RANTES) and Th2 counterparts such as IL-4, monocyte chemoattractant protein-l (MCP-l). Methods: Proliferation and mRNA expression of IFN-$\gamma$, RANTES and MCP-l by RT-PCR in peripheral blood mononuclear cells (PBMCs) in response to in vitro stimulation with mycobacterial antigens were compared in pulmonary tuberculosis patients with cured and treatment failure and in tuberculin-positive and tuberculin-negative healthy subjects. Results: Defective proliferative responsiveness to aqueous TSP antigen was involved with treatment failure tuberculosis patients. Aqueous TSP antigen-induced IFN-$\gamma$ and RANTES mRNA expression was decreased in treatment failure tuberculosis patients compared with healthy tuberculin reactors and cured tuberculosis patients (23.1 % versus 90.0% for IFN-$\gamma$ and 46.2% versus 70.0% versus 46.2% for RANTES). The frequency of MCP-l mRNA expression to aqueous TSP antigen in treatment failure tuberculosis patients was greater than in healthy tuberculin reactors and cured tuberculosis patients (76.9% versus 40.0%). Conclusion: The increasing expression of MCP-1 mRNA in response to aqueous TSP antigen might be predicted to favor Th1 responses and restricted Th1 responses in treatment failure of pulmonary tuberculosis.