• Journal of Microbiology and Biotechnology
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• v.18 no.1
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• pp.171-175
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• 2008

Here, we report that Vibrio parahaemolyticus induces a rapid remodeling of macrophage actin and activates RhoB GTPase. Mutational analysis revealed that the effects depend on type III secretion system 1 regulated translocation of a V. parahaemolyticus effector protein, VP1686, into the macrophages. Remodeling of actin is shown to be necessary for increased bacterial uptake followed by initiation of apoptosis in macrophages. This provides evidence for functional association of the VP1686 in triggering an eat me-and-die signal to the host.

• Journal of Microbiology and Biotechnology
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• v.27 no.10
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• pp.1727-1735
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• 2017

Hepatitis E virus (HEV) infections cause epidemic or sporadic acute hepatitis, which are mostly self-limiting. However, viral infection in immunocompromised patients and pregnant women may result in serious consequences, such as chronic hepatitis and liver damage, mortality of the latter of which reaches up to 20-30%. Type I interferon (IFN)-induced antiviral immunity is known to be the first-line defense against virus infection. Upon HEV infection in the cell, the virus genome is recognized by pathogen recognition receptors, leading to rapid activation of intracellular signaling cascades. Expression of type I IFN triggers induction of a barrage of IFN-stimulated genes, helping the cells cope with viral infection. Interestingly, some of the HEV-encoded genes seem to be involved in disrupting signaling cascades for antiviral immune responses, and thus crippling cytokine/chemokine production. Antagonistic mechanisms of type I IFN responses by HEV have only recently begun to emerge, and in this review, we summarize known HEV evasion strategies and compare them with those of other hepatitis viruses.

• Journal of Ginseng Research
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• v.45 no.4
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• pp.535-537
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• 2021

In the 1918 influenza pandemic, more than 95% of mortalities were ascribed to bacterial pneumonia. After the primary influenza infection, the innate immune system is attenuated, and the susceptibility to bacteria is increased. Subsequent bacterial pneumonia exacerbates morbidity and increases the mortality rate. Similarly, COVID-19 infection attenuates innate immunity and results in pneumonia. In addition, the current pneumococcal conjugate vaccine may have limited defense against secondary pneumococcal infection after influenza infection. Therefore, until a fully protective vaccine is available, a method of increasing immunity may be helpful. Ginseng has been shown to increase the defense against influenza in clinical trials and animal experiments, as well as the defense against pneumococcal pneumonia in animal experiments. Based on these findings, ginseng is suspected to be helpful for providing immunity against COVID-19.

• The Korean Journal of Oral and Maxillofacial Pathology
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• v.41 no.3
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• pp.121-129
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• 2017

Coffee (Coffea spp.) is one of the most important agricultural commodities, being widely consumed in the world. Various beneficial health effects of coffee have been extensively investigated, but data on habitual coffee consumption and its bio-physiological effect have not been clearly explained as well as it is not proved the cause and effect between drinking coffee and its bio-physiological reactions. We made the dialyzed coffee extract (DCE), which is absorbable through gastrointestinal tract, in order to elucidate the cellular effect of whole small coffee molecules. RAW 264.7 cells, a murine macrophage lineage, were directly treated with DCE, i.e., DCE-2.5 (equivalent to 2.5 cups of coffee a day), DCE-5, and DCE-10, for 12 hours, and their protein extracts were examined by immunoprecipitation high performance liquid chromatography (IP-HPLC). RAW 264.7 cells differently expressed the inflammation-related proteins depending on the doses of DCE. RAW 264.7 cells treated with DCE showed marked increase of cathepsin C, cathepsin G, CD20, CD28, CD31, CD68, indicating the activation of innate immunity. Particularly, the macrophage biomarkers, cathepsin G, cathepsin C, CD31, and CD68 were markedly increased after DCE-5 and DCE-10 treatments, and the lymphocyte biomarkers, CD20 and CD28 were consistently increased and became marked after DCE-10 treatment. On the other hand, RAW 264.7 cells treated with DCE showed consistent increase of IL-10, an anti-inflammatory factor, but gradual decreases of different pro-inflammatory proteins including $TNF{\alpha}$, COX-2, lysozyme, MMP-2, and MMP-3. In particular, the cellular signaling of inflammation was gradually mitigated by the reduction of $TNF{\alpha}$, COX-2, IL-12, and M-CSF, and also the matrix inflammatory reaction was reduced by marked deceases of MMP-2, MMP-3, and lysozyme. These anti-inflammatory expressions were consistently found until DCE-10 treatment. Therefore, it is presumed that DCE may have dynamic effects of innate immunity activation and pro-inflammation suppression on RAW264.7 cells simultaneously. These effects were consistently found in the highest dose of coffee, DCE-10 (equivalent to 10 cups of coffee a day in man), that might imply the small coffee molecules were accumulated in RAW 264.7 cells after DCE-10 treatment and produce synergistic cytokine effects for innate immunity activation and anti-inflammatory reaction concurrently.

• IMMUNE NETWORK
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• v.21 no.1
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• pp.1.1-1.16
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• 2021

The emergence of a new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has become a significant health concern worldwide. Undoubtedly, a better understanding of the innate and adaptive immune responses against SARS-CoV-2 and its relationship with the coronavirus disease 2019 (COVID-19) pathogenesis will be the sole basis for developing and applying therapeutics. This review will summarize the published results that relate to innate immune responses against infections with human coronaviruses including SARS-CoV-1 and SARS-CoV-2 in both humans and animal models. The topics encompass the innate immune sensing of the virus to the dysregulation of various innate immune cells during infection and disease progression.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.7
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• pp.1019-1025
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• 2011

Toll-like receptors (TLRs) play an important role in the recognition of invading pathogens and the modulation of innate immune responses in mammals. The TLR4 and TLR7 are well known to recognize the bacterial lipopolysaccharide (LPS) and single stranded (ssRNA) ligands, respectively and play important role in host defense against Gram-negative bacteria and ssRNA viruses. In the present study, coding exon fragments of these two TLRs were identified, cloned, sequenced and analyzed in terms of insertion-deletion polymorphism, within bovine TLRs 4 and 7, thereby facilitating future TLR signaling and association studies relevant to bovine innate immunity. Comparative sequence analysis of TLR 4 exons revealed that this gene is more variable, particularly the coding frame (E3P1), while other parts showed percent identity of 95.7% to 100% at nucleotide and amino acid level, respectivley with other Bos indicus and Bos taurus breeds from different parts of the world. In comparison to TLR4, sequence analysis of TLR7 showed more conservation among different B. indicus and B. taurus breeds, except single point mutation at 324 nucleotide position (AAA to AAM) altering a single amino acid at 108 position (K to X). Percent identity of TLR7 sequences (all 3 exons) was between 99.2% to 100% at nucleotide and amino acid level, when compared with available sequence database of B. indicus and B. taurus. Simple Modular Architecture Research Tool (SMART) analysis showed variations in the exon fragments located in the Leucine Rich Repeat (LRR) region, which is responsible for binding with the microbial associated molecular patterns and further, downstream signaling to initiate anti-microbial response. Considering importance of TLR polymorphism in terms of innate immunity, further research is warranted.

• Fisheries and Aquatic Sciences
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• v.16 no.1
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• pp.7-14
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• 2013

A 10-week feeding trial was conducted to examine the effects of dietary spirulina and quercetin on growth, innate immunity, disease resistance and dietary antioxidant capacity in the juvenile olive flounder. Triplicate groups of fish (initial body weight, $2.9{\pm}0.01g$) were fed one of isonitrogenous (48% crude protein) and isocaloric (17.4 MJ/kg DM) experimental diets containing 0% spirulina (as a control), 3.4% spirulina, or 6.8% spirulina with or without supplementation of 0.5% quercetin (designated as CON, SP3.4, SP6.8, and SP6.8 + Q, respectively) at a rate of 3% body mass twice daily. Higher dietary antioxidant capacity was found with spirulina supplementation, and the highest value (P < 0.05) was obtained with SP6.8 + Q diet. At the end of the feeding trial, no significant effects were observed on growth performance, body composition and disease resistance against Edwardsiella tarda. Lysozyme activity was significantly increased by spirulina supplementation (P < 0.05), and the highest value was observed in the group fed SP6.8 + Q diet. Also, significantly higher respiratory burst activity (P < 0.05) was found in SP3.4 group. According to the results of this study, dietary supplementation of 3.4% spirulina may enhance innate immunity of olive flounder.

• Journal of Animal Science and Technology
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• v.64 no.1
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• pp.123-134
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• 2022

Toll-like receptors (TLRs), as a part of innate immunity, plays an important role in detecting pathogenic molecular patterns (PAMPs) which are structural components or product of pathogens and initiate host defense systems or innate immunity. Precise negative feedback regulations of TLR signaling are important in maintaining homeostasis to prevent tissue damage by uncontrolled inflammation during innate immune responses. In this study, we identified and characterized the function of the pancreatic progenitor cell differentiation and proliferation factor (PPDPF) as a negative regulator for TLR signal-mediated inflammation in chicken. Bioinformatics analysis showed that the structure of chicken PPDPF evolutionarily conserved amino acid sequences with domains, i.e., SH3 binding sites and CDC-like kinase 2 (CLK2) binding sites, suggesting that relevant signaling pathways might contribute to suppression of inflammation. Our results showed that stimulation with polyinosinic:polycytidylic acids (Poly [I:C]), a synthetic agonist for TLR3 signaling, increased the mRNA expression of PPDPF in chicken fibroblasts DF-1 but not in chicken macrophage-like cells HD11. In addition, the expression of pro-inflammatory genes stimulated by Poly(I:C) were reduced in DF-1 cells which overexpress PPDPF. Future studies warrant to reveal the molecular mechanisms responsible for the anti-inflammatory capacity of PPDPF in chicken as well as a potential target for controlling viral resistance.

• Proceedings of the Microbiological Society of Korea Conference
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• 2008.05a
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• pp.28-28
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• 2008

• IMMUNE NETWORK
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• v.5 no.3
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• pp.137-143
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• 2005

Background: Millions of people in the world are suffering from atopic dermatitis (AD), which is a chronic inflammatory skin disease triggered by Th2 immune responses. The NC/Nga mouse is the most extensively studied animal model of AD. Like human AD, NC/Nga mice demonstrate increased levels of IgE, a hallmark of Th2 immune responses. Adaptive immunity cannot be generated without help of innate immunity. Especially natural killer T (NKT) cells and marginal zone B (MZB) cells have been known to play important roles in linking innate immunity to adaptive immunity. Methods: Through flow cytometric analysis and ELISA assay, we investigated whether these lymphocytes might be altered in number in NC/Nga mice. Results: Our data demonstrated that the number of NKT cells was reduced in NC/Nga mice and IFN${\gamma}$ production by NKT cells upon ${\alpha}-GalCer$ stimulation decreased to the levels of CD1d KO mice lacking in NKT cells. However, reduction of NKT cells in NC/Nga mice was not due to CD1d expression, which was normal in the thymus. Interestingly, there was a significant increase of $CD1d^{high}B220^+$ cells in the spleen of NC/Nga mice. Further, we confirmed that $CD1d^{high}B220^+$ cells are B cells, not dendritic cells. These $CD1d^{high}B220^+$ B cells show $IgM^{high}CD21^{high}CD23^{low}$, a characteristic phenotype of MZB cells. Conclusion: We provide the evidence that there are decreased activities of NKT cells and increased number of MZB cells in the NC/Nga mice. Our findings may thus explain why NC/Nga mice are susceptible to AD.