• Journal of Microbiology and Biotechnology
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• 제27권11호
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• pp.1971-1982
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• 2017

Piliated Lactobacillus rhamnosus (pLR) strains possess higher adherent capacity than non-piliated strains. The objective of this study was to isolate and characterize probiotic pLR strains in human fecal samples. To this end, mouse polyclonal antiserum (anti-SpaA) against the recombinant pilus protein (SpaA) of L. rhamnosus strain GG (LGG) was prepared and tested for its reactivity and specificity. With the anti-SpaA, a method combining the de Man, Rogosa, and Sharpe (MRS) agar plating separation and colony immunoblotting (CIB) was developed to isolate pLR from 124 human fecal samples. The genetic and phenotypic characteristics of the resultant pLR isolates were compared by randomly amplified polymorphic DNA (RAPD) fingerprinting, and examination of adhesion to Caco-2 cells, hydrophobicity, autoaggregation, and in vitro gastrointestinal tolerance. Anti-SpaA specifically reacted with three pLR strains of 25 test strains, as assessed by western blotting, immunofluorescence flow cytometry, and immunoelectron microscopy (IEM) assays. The optimized MRS agar separation plus anti-SpaA-based CIB procedure could quantitatively detect $2.5{\times}10^3CFU/ml$ of pLR colonies spiked in $10^6CFU/ml$ of background bacteria. Eight pLR strains were identified in 124 human fecal samples, and were confirmed by 16S RNA gene sequencing and IEM identification. RAPD fingerprinting of the pLR strains revealed seven different patterns, of which only two isolates from infants showed the same RAPD profiles with LGG. Strain PLR06 was obtained with high adhesion and autoaggregation activities, hydrophobicity, and gastrointestinal tolerance. Anti-SpaA-based CIB is a rapid and inexpensive method for the preliminary screening of novel adherent L. rhamnosus strains for commercial purposes.

• 한국미생물·생명공학회지
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• 제20권3호
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• pp.301-310
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• 1992

요로계 감염에 대처함에 있어 hemolysin과 Gal-Gal pili의 multicomponent 백신 개발 가능성을 조사하기 위하여 본 연구를 수행하였다. 요로계 감염환자로부터 분리되어 그의 hemolysin gene 의 염기배열과 아미노산 배열이 밝혀진 대장균 J96 균중의 hemolysin에 대하여 10곳에 해당하는 20 mer-oligonucleotide를 합성하였다. 이들 probe를 사용하여 요로계감염 환자들로부터 분리한 wild type 대장균들의 DNA에 대하여 hemolysin gene 의 상동성을 조사하였는 바 8개의 probe는 거의 모든 hemolysin signal을 보여주었고 HA484는 28.3, HA661은 71.7의 positive signal을 나타내었다.이는 요로계 감염 대장균들의 Hemolysin gene의 상동성이 매우 높은 것을 의미한다. 또한 J96 hemolysin에 대한 12개의 MAB은 모두 wild type 대장균들이 분비하는 90% 이상의 균주에 대하여 양성 immunoblotting을 나타내었다. 특히 J96 hemolysin의 functional site를 가장 강력하게 block할 수 있는 monoclonal antibody MAＢ132가 모든 wild type으로부터 분리된 hemolysin의 function을 중화시킬수 있는 결과는 J96의 cloned hemolysin product를 vaccine으로 사용할 수 있는 가능성을 증대시키는 결과라고 할 수 있다.

• Journal of Ginseng Research
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• 제43권4호
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• pp.692-698
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• 2019

Background: Breast cancer is a severe disease and the second leading cause of cancer death in women worldwide. To surmount this, various diagnosis and treatment options for breast cancer have been developed. One of the most effective strategies for cancer treatment is to induce apoptosis using naturally occurring compounds. Compound K (CK) is a ginseng saponin metabolite generated by human intestinal bacteria. CK has been studied for its cardioprotective, antiinflammatory, and liver-protective effects; however, the role of CK in breast cancer is not fully understood. Methods: To investigate the anticancer effects of CK in SKBR3 and MDA-MB-231 cells, cell viability assays and flow cytometry analysis were used. In addition, the direct targets of CK anticancer activity were identified using immunoblotting analysis and overexpression experiments. Invasion, migration, and clonogenic assays were carried out to determine the effects of CK on cancer metastasis. Results: CK-induced cell apoptosis in SKBR3 cells as determined through 3-(4-5-dimethylthiazol-2-yl)-2-5-diphenyltetrazolium bromide assays, propidium iodide (PI) and annexin V staining, and morphological changes. CK increased the cleaved forms of caspase-7, caspase-8, and caspase-9, whereas the expression of Bcl-2 was reduced by CK. In assays probing the cell survival pathway, CK activated only AKT1 and not AKT2. Moreover, CK inhibited breast cancer cell invasion, migration, and colony formation. Through regulation of AKT1 activity, CK exerts anticancer effects by inducing apoptosis. Conclusion: Our results suggest that CK could be used as a therapeutic compound for breast cancer.

• Journal of Veterinary Science
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• 제25권1호
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• pp.4.1-4.14
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• 2024

Background: Lawsonia intracellularis is the causative agent of proliferative enteropathy and is associated with several outbreaks, causing substantial economic loss to the porcine industry. Objectives: In this study, we focused on demonstrating the protective effect in the mouse model through the immunological bases of two vaccine strains against porcine proliferative enteritis. Methods: We used live-attenuated Salmonella Typhimurium (ST) secreting two selected immunogenic LI antigens (Lawsonia autotransporter A epitopes and flagellin [FliC]-peptidoglycan-associated lipoprotein-FliC) as the vaccine carrier. The constructs were cloned into a Salmonella expression vector (pJHL65) and transformed into the ST strain (JOL912). The expression of immunogenic proteins within Salmonella was evaluated via immunoblotting. Results: Immunizing BALB/c mice orally and subcutaneously induced high levels of LI-specific systemic immunoglobulin G and mucosal secretory immunoglobulin A. In immunized mice, there was significant upregulation of interferon-γ and interleukin-4 cytokine mRNA and an increase in the subpopulations of cluster of differentiation (CD) 4⁺ and CD 8⁺ T lymphocytes upon splenocytes re-stimulation with LI antigens. We observed significant protection in C57BL/6 mice against challenge with 10^6.9 times the median tissue culture infectious dose of LI or 2 × 10⁹ colony-forming units of the virulent ST strain. Immunizing mice with either individual vaccine strains or co-mixture inhibited bacterial proliferation, with a marked reduction in the percentage of mice shedding Lawsonia in their feces. Conclusions: Salmonella-mediated LI gene delivery induces robust humoral and cellular immune reactions, leading to significant protection against LI and salmonellosis.