• Journal of Microbiology and Biotechnology
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• 제26권9호
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• pp.1517-1526
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• 2016

Lactic acid bacteria (LAB) isolated from fermented foods have potential as a treatment for immune-related disorders and the use of LAB has been increasing worldwide. In this study, the differential cytokine regulatory effect was examined with three isolates of lactobacilli strains; namely, Lactobacillus plantarum K55-5 isolated from dairy product, and L. sakei K101 and L. plantarum K8 previously isolated from kimchi (a Korean traditional fermented vegetable). Production of cytokines such as IL-10, IL-12, IFN-γ, and TNF-α was significantly increased in L. sakei K101- and L. plantarum K55-5-treated splenocytes as compared with controls. The oral administration of L. sakei K101 and L. plantarum K55-5 increased cytokine production in the immunosuppressed mouse splenocytes and blood. NK cell cytotoxic activity was also increased in L. sakei K101- and L. plantarum K55-5-fed mice. On the other hand, L. plantarum K8 did not affect cytokine induction in all the experiments performed in this study. The cytokine-inducing effect of L. plantarum K55-5 was significantly increased by lysates of heat-killed bacteria as compared with live, heat-killed, or supernatant of cell lysates. TNF-α production by lipoteichoic acids (LTAs) isolated from the three isolates of lactobacilli was compared, and it was found that K55-5 LTA had a highest cytokine-inducing ability, which was mediated by TLR2-mediated NF-κB and ERK activation. Taken together, our study suggests that L. plantarum K55-5 and L. sakei K101 can be used for the treatment of immunosuppressed disorders.

• Journal of Microbiology and Biotechnology
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• 제24권2호
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• pp.245-253
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• 2014

A fibrinolytic enzyme was produced by an edible mushroom of Pleurotus ostreatus using submerged culture fermentation. The enzyme was purified from the culture supernatant by applying a combination of freeze-thaw treatment, ammonium sulfate precipitation, hydrophobic interaction, and gel filtration chromatographies. The enzyme was purified by a 147-fold, with a yield of 7.54%. The molecular masses of the enzyme an determined by gel filtration and SDS-PAGE were 13.6 and 18.2 kDa, respectively. The isoelectric point of the enzyme was 8.52. It hydrolyzed fibrinogen by cleaving the ${\alpha}$ and ${\beta}$ chains of fibrinogen followed by the ${\gamma}$ chains, and also activated plasminogen into plasmin. The enzyme was optimally active at $45^{\circ}C$ and pH 7.4. The enzyme activity was completely inhibited by EDTA, whereas protease inhibitors of TPCK, SBTI, PMSF, aprotinin and pepstatin showed no inhibition on its activity. The partial amino acid sequences of the enzyme as determined by Q-TOF2 were ATFVGCSATR, GGTLIHESSHFTR, and YTTWFGTFVTSR. These sequences showed a high degree of homology with those of metallo-endopeptidases from P. ostreatus and Armillaria mellea. The purified enzyme can also be applied as a natural agent for oral fibrinolytic therapy or prevention of thrombosis.

• Journal of Microbiology and Biotechnology
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• 제24권2호
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• pp.217-224
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• 2014

Chicken are considered as the most important source of human infection by Campylobacter jejuni, which primarily arises from contaminated poultry meats. However, the genes expressed in vivo of the interaction between chicken and C. jejuni have not been screened. In this regard, in vivo-induced antigen technology (IVIAT) was applied to identify expressed genes in vivo during interaction between chicken and C. jejuni, a prevalent foodborne pathogen worldwide. Chicken sera were obtained by inoculating C. jejuni NCTC 11168 into Leghorn chickens through oral and intramuscular administration. Pooled chicken sera, adsorbed against in vitro-grown cultures of C. jejuni, were used to screen the inducible expression library of genomic proteins from sequenced C. jejuni NCTC 11168. Finally, 28 unique genes expressed in vivo were successfully identified after secondary and tertiary screenings with IVIAT. The genes were implicated in metabolism, molecular biosynthesis, genetic information processing, transport, regulation and other processes, in addition to Cj0092, with unknown function. Several potential virulence-associated genes were found to be expressed in vivo, including chuA, flgS, cheA, rplA, and Cj0190c. We selected four genes with different functions to compare their expression levels in vivo and in vitro using real-time RT-PCR. The results indicated that these selected genes were significantly upregulated in vivo but not in vitro. In short, the expressed genes in vivo may act as potential virulence-associated genes, the protein encoded by which may be meaningful vaccine candidate antigens for campylobacteriosis. IVIAT provides an important and efficient strategy for understanding the interaction mechanisms between Campylobacter and hosts.

• Journal of Microbiology and Biotechnology
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• 제13권4호
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• pp.552-559
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• 2003

The FimH subunit of type 1-fimbriated Escherichiu coli (E. coli) has been determined as a major cause for urinary tract infections. Thus, to produce a possible vaccine antigen against urinary tract infections, the fimIH gene was genetically coupled to the ctxa2b gene and cloned into a pMAL-p2E expression vector. The chimeric construction of pMALfimH/ctxa2b was then transformed into E. coli K-12 TB1 and its nucleotide sequence was verified. A fusion protein, based on fusing adhesin to the cholera toxin subunit A2B (CTXA2B), was induced with 0.01 mM isopropyl-${\beta}-D-thiogalactoside$ (IPTG) for 4 h at $37^{\circ}C$ to yield a soluble fusion protein. The fusion protein was then purified by affinity chromatography. The expressed fusion protein was confirmed by SDS-PAGE and Western blotting using antibodies to the maltose binding protein (MBP) or the cholera toxin subunit B (CTXB), plus the N-terminal amino acid sequence was also analyzed. The orderly-assembled fusion protein was confirmed by a modified $G_{Ml}-ganglioside$ ELISA, using antibodies to adhesin. The results indicated that the purified fusion protein was an adhesin/CTXA2B protein containing E. coli adhesin and the $G_{Ml}-ganglioside$ binding activity of CTXB. Accordingly, this adhesin/CTXA2B protein may be a potential antigen for oral immunization against uropathogenic E. coli.

• Journal of Microbiology and Biotechnology
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• 제25권9호
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• pp.1532-1536
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• 2015

To investigate the memory-enhancing effect of lactic acid bacteria, we selected the probiotic mixture KF, which consisted of Lactobacillus plantarum KY1032 and Lactobacillus curvatus HY7601 (1 × 10¹¹ CFU/g of each strain), and investigated its antilipidemic and memoryenhancing effects in aged Fischer 344 rats. KF (1 × 10¹⁰ CFU/rat/day), which was administered orally once a day (6 days per week) for 8 weeks, significantly inhibited age-dependent increases of blood triglyceride and reductions of HDL cholesterol (p < 0.05). KF restored agereduced spontaneous alternation in the Y-maze task to 94.4% of that seen in young rats (p < 0.05). KF treatment slightly, but not significantly, shortened the escape latency daily for 4 days. Oral administration of KF restored age-suppressed doublecortin and brain-derived neurotrophic factor expression in aged rats. Orally administered KF suppressed the expression of p16, p53, and cyclooxygenase-2, the phosphorylation of Akt and mTOR, and the activation of NF-κB in the hippocampus of the brain. These findings suggest that KF may ameliorate age-dependent memory deficit and lipidemia by inhibiting NF-κB activation.

• Journal of Microbiology and Biotechnology
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• 제18권8호
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• pp.1393-1400
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• 2008

Recent study has demonstrated an increasing prevalence of food allergy in Korean children. Specific probiotic bacteria may promote potentially anti-allergenic processes through induction of Th1-type immunity and enhance the regulatory lymphocyte. This study investigated whether orally administrated probiotics could suppress allergic responses in an ovalbumin (OVA)-induced allergy mouse model. Thus, female C3H/HeJ mice were orally sensitized with OVA and cholera toxin for 4 weeks. Lactobacillus acidophilus AD031, Bifidobacterium lactis AD011, and L. acidophilus AD031 plus B. lactis AD011 were fed to mice from 2 weeks before the sensitization. The OVA-induced mice that were not treated with probiotics had significantly increased serum levels of OVA-specific IgE and IgG1, and OVA-specific IgA in feces. However, the mice treated with probiotics suppressed production of the OVA-specific IgE, IgG1, and IgA. The level of IL-4 was significantly lower, and the levels of INF-$\gamma$ and IL-10 were significantly higher in the mice treated with probiotics than that in the non-treated mice. The groups treated with probiotics had decreased levels of degranulated mast cells, eosinophil granules, and tail scabs. These results indicate that L. acidophilus AD031 and B. lactis AD011 might be useful for the prevention of allergy.

• Journal of Microbiology and Biotechnology
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• 제19권3호
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• pp.314-322
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• 2009

Four different bacterial colonies were isolated from an old stock of an entomopathogenic nematode, Steinernema monticolum. They all showed entomopathogenicity to final instar larvae of beet armyworm, Spodoptera exigua, by hemocoelic injection. However, they varied in colony form, susceptibility to antibiotics, and postmortem change of the infected host insects. Biolog microbial identification and 16S rDNA sequence analyses indicate that these are four different species classified into different bacterial genera. Owing to high entomopathogenicity and a cadaver color of infected insect host, Serratia sp. was selected as a main symbiotic bacterial species and analyzed for its pathogenicity. Although no virulence of Serratia sp. was detected at oral administration, the bacteria gave significant synergistic pathogenicity to fifth instar S. exigua when it was treated along with a spore-forming entomopathogenic bacterium, Bacillus thuringiensis. The synergistic effect was explained by an immunosuppressive effect of Serratia sp. by its high cytotoxic effect on hemocytes of S. exigua, because Serratia sp. caused septicemia of S. exigua when the bacterial cells were injected into S. exigua hemocoel. The cytotoxic factor(s) was present in the culture medium because the sterilized culture broth possessed high potency in the cytotoxicity, which was specific to granular cells and plasmatocytes, two main immune-associated hemocytes in insects.

• Journal of Microbiology and Biotechnology
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• 제24권8호
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• pp.1143-1147
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• 2014

Human papillomavirus (HPV) infection is considered to play a critical role in the development of cervical carcinoma, which is the third most common cancer among Korean females. Here, we performed a baseline study of HPV infection and genotyping using an HPV DNA chip, which is a type of oligonucleotide microarray. A total of 6,855 cervical swab specimens from 5,494 women attending Dankook University Hospital Health Improvement Center in Cheonan, Korea between 2006 and 2012, originally collected for HPV infection screening, were genotyped for HPV. The extracted DNA from the cervical specimens was investigated by an HPV DNA chip designed to detect 41 different HPV types. HPV was identified as positive in 1,143 (16.7%) of the 6,855 samples. The most frequently detected HPV genotypes were HPV types 16, 53, 56, 58, 39, 52, 70, 84, 68, 62, 35, 54, 81, 18, and 30, in descending order of incidence. The proportions of single and multiple HPV infections in the HPV-positive specimens were 78.1% and 21.9%, respectively. The average age of HPV-positive patients was 39.9 years, with the positive rate of HPV being the highest in the 10-29 age group (20.6%). We report here on the prevalence and distribution of 41 different genotypes of HPV according to age among women in Cheonan, Korea. These data may be of use as baseline data for the assessment of public health-related issues and for the development of area-specific HPV vaccines.

• Journal of Microbiology and Biotechnology
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• 제23권5호
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• pp.724-730
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• 2013

We investigated the effects of orally administered probiotic bacteria (Lactobacillus species) as allergic immune modulators in ovalbumin (OVA)-sensitized mice. BALB/c mice were intraperitoneally injected with OVA twice at a 2-week interval for allergy sensitization. The mice were then orally administered Lactobacillus casei YIT9029 (L1), L. casei HY7201 (L2), L. brevis HY7401 (L3), or L. plantarum HY20301 (L4) every 2 days for 3 weeks. Total IgE levels significantly decreased in sera of L3-administered mice but increased in the other groups. OVA-specific IgE levels decreased slightly in sera of mice administered L1, L3, and L4 but increased significantly in L2-administered mice. In passive cutaneous anaphylaxis (PCA) using sera from administered mice, only the L3-administered group showed reaction inhibition. High expression of TLR-2 with interferon (IFN)-${\gamma}$ stimulation on peripheral blood mononuclear cells occurred in L3- or L4-administered mice. Th1 cytokines, including IFN-${\gamma}$ and interleukin (IL)-12, increased in splenocytes of L3-administered mice; however, IL-4 decreased in L1- and L4-administered groups; IL-5 decreased in all experimental groups. IL-6 decreased in the L3-administered group; and IL-10 decreased in L1-, L2-, and L3-administered groups. L3 induced antiallergic effects by increasing Th1 cytokines, decreasing Th2 cytokines, and inhibiting the PCA reaction, whereas L2 administration increased allergic effects.

• Journal of Microbiology and Biotechnology
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• 제28권2호
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• pp.218-226
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• 2018

Nanometric Lactobacillus plantarum nF1 (nLp-nF1) is a biogenics consisting of dead L. plantarum cells pretreated with heat and a nanodispersion process. In this study, we investigated the immune-enhancing effects of nLp-nF1 in vivo and in vitro. To evaluate the immunostimulatory effects of nLp-nF1, mice immunosuppressed by cyclophosphamide (CPP) treatment were administered with nLp-nF1. As expected, CPP restricted the immune response of mice, whereas oral administration of nLp-nF1 significantly increased the total IgG in the serum, and cytokine production (interleukin-12 (IL-12) and tumor necrosis factor alpha (TNF-${\alpha}$)) in bone marrow cells. Furthermore, nLp-nF1 enhanced the production of splenic cytokines such as IL-12, TNF-${\alpha}$, and interferon gamma (IFN-${\gamma}$). In vitro, nLp-nF1 stimulated the immune response by enhancing the production of cytokines such as IL-12, TNF-${\alpha}$, and IFN-${\gamma}$. Moreover, nLp-nF1 given a food additive enhanced the immune responses when combined with various food materials in vitro. These results suggest that nLp-nF1 could be used to strengthen the immune system and recover normal immunity in people with a weak immune system, such as children, the elderly, and patients.