• Title/Summary/Keyword: innate immune response

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Structure-activity relationships of the intramolecular disulfide bonds in coprisin, a defensin from the dung beetle

  • Lee, Jaeho;Lee, Daeun;Choi, Hyemin;Kim, Ha Hyung;Kim, Ho;Hwang, Jae Sam;Lee, Dong Gun;Kim, Jae Il
    • BMB Reports
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    • v.47 no.11
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    • pp.625-630
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    • 2014
  • Defensins, which are small cationic molecules produced by organisms as part of their innate immune response, share a common structural scaffold that is stabilized by three disulfide bridges. Coprisin is a 43-amino acid defensin-like peptide from Copris tripartitus. Here, we report the intramolecular disulfide connectivity of cysteine-rich coprisin, and show that it is the same as in other insect defensins. The disulfide bond pairings of coprisin were determined by combining the enzymatic cleavage and mass analysis. We found that the loss of any single disulfide bond in coprisin eliminated all antibacterial, but not antifungal, activity. Circular dichroism (CD) analysis showed that two disulfide bonds, Cys20-Cys39 and Cys24-Cys41, stabilize coprisin's ${\alpha}$-helical region. Moreover, a BLAST search against UniProtKB database revealed that coprisin's ${\alpha}$-helical region is highly homologous to those of other insect defensins.

Induction of the Neutrophil Migration in Normal Subjects due to Asthmatic Bronchoalveolar Lavage Fluid (BALF)

  • Lee, Ji-Sook;Choi, Eugene;Yang, Eun Ju;Lee, Na Rae;Baek, Seung Yeop;Kim, Eun Jeong;Kim, In Sik
    • Biomedical Science Letters
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    • v.20 no.3
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    • pp.111-116
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    • 2014
  • Human neutrophils play an essential role in the innate immune response and are involved in the pathogenesis of the severe and corticosteroid-resistant asthma. Asthma is characterized by an infiltration of inflammatory cells into the lung and by a cytokine release. The aim of this study is to investigate the effects of a bronchoalveolar lavage fluid (BALF) on the chemotaxis and apoptosis of neutrophils which were isolated from healthy subjects. The BALF of subjects with asthma induces the blood neutrophil chemotaxis in the opposite of that in normal subjects. The IL-8, IL-6, and monocyte chemoattractant protein-1 (MCP-1) levels in BALF were higher in subjects with asthma than in normal subjects. The BALF of normal and asthmatic subjects has no effect on neutrophil apoptosis of BALF. MCP-1 delays the constitutive apoptosis of normal blood neutrophils, but has no effect in normal BALF neutrophils. These results may indicate that inflammatory factors secreted by the lung tissue of patients with asthma trigger the neutrophil chemotaxis and also induce the neutrophil dysregulation.

Peptidoglycans Promotes Human Leukemic THP-1 Cell Apoptosis and Differentiation

  • Wang, Di;Xiao, Pei-Ling;Duan, Hua-Xin;Zhou, Ming;Liu, Jin;Li, Wei;Luo, Ke-Lin;Chen, Jian-Jun;Hu, Jin-Yue
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.12
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    • pp.6409-6413
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    • 2012
  • The innate immune system coordinates the inflammatory response to pathogens. To do so, its cells must discriminate self from non-self utilizing receptors that identify molecules synthesized exclusively by microbes. Toll-like receptors have a crucial role in the detection of microbial infection in mammals and insects. In mammals, they have evolved to recognize conserved products unique to microbial metabolism. These include lipopolysaccharide (LPS), lipotechoic acids, and peptidoglycans (PGN). We show here that TLRs, including TLR2, are expressed on the THP-1 human leukemia cell line. Activation of TLR2 signaling in THP-1 by PGN induces the synthesis of various soluble factors and proteins including interleukin-$1{\beta}$, interleukin-8 and TNF-${\alpha}$ and apoptosis of THP-1 with PGN dose and time dependence. Moreover, in this study we show that PGN induces apoptosis of THP-1 cells in a TNF-${\alpha}$-dependent manner. These findings indicate that TLR2 signaling results in a cascade leading to tumor apoptosis and differentiation, which may suggest new clinical prospects using TLR2 agonists as cytotoxic agents in certain cancers.

Cell Motility Is Decreased in Macrophages Activated by Cancer Cell-Conditioned Medium

  • Go, Ahreum;Ryu, Yun-Kyoung;Lee, Jae-Wook;Moon, Eun-Yi
    • Biomolecules & Therapeutics
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    • v.21 no.6
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    • pp.481-486
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    • 2013
  • Macrophages play a role in innate immune responses to various foreign antigens. Many products from primary tumors influence the activation and transmigration of macrophages. Here, we investigated a migration of macrophages stimulated with cancer cell culture-conditioned medium (CM). Macrophage activation by treatment with CM of B16F10 cells were judged by the increase in protein levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX2). The location where macrophages were at 4 h-incubation with control medium or CM was different from where they were at 5 h-incubation in culture dish. Percentage of superimposed macrophages at every 1 h interval was gradually increased by CM treatment as compared to control. Total coverage of migrated track expressed in coordinates was smaller and total distance of migration was shorter in CM-treated macrophages than that in control. Rac1 activity in CM-treated macrophages was also decreased as compared to that in control. When macrophages were treated with CM in the presence of dexamethasone (Dex), an increase in COX2 protein levels, and a decrease in Rac1 activity and total coverage of migration were reversed. In the meanwhile, biphasic changes were detected by Dex treatment in section distance of migration at each time interval, which was more decreased at early time and then increased at later time. Taken together, data demonstrate that macrophage motility could be reduced in accordance with activation in response to cancer cell products. It suggests that macrophage motility could be a novel marker to monitor cancer-associated inflammatory diseases and the efficacy of anti-inflammatory agents.

Polymorphism of NLRP3 Gene and Association with Susceptibility to Digestive Disorders in Rabbit

  • Yang, Yu;Zhang, Gong-Wei;Chen, Shi-Yi;Peng, Jin;Lai, Song-Jia
    • Asian-Australasian Journal of Animal Sciences
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    • v.26 no.4
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    • pp.455-462
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    • 2013
  • NLR family pyrin domain containing 3 (NLRP3) is a key component of the inflammasome, whose assembly is a crucial part of the innate immune response. The aim of the present study was to evaluate the association between exon 3 polymorphisms of NLRP3 and the susceptibility to digestive disorders in rabbits. In total, five coding single-nucleotide polymorphisms (cSNPs) were identified; all of which are synonymous. Among them, c.456 C> and c.594 G> were further genotyped for association analysis based on case-control design (n =162 vs n =102). Meanwhile, growing rabbits were experimentally induced to digestive disorders by feeding a fiber-deficient diet, subsequently they were subjected to mRNA expression analysis. Association analysis revealed that haplotype H1 (the two cSNPs: GT) played a potential protective role against digestive disorders (p<0.001). The expression of NLRP3 in the group $H1HX_1$ ($H1HX_1$ is composed of H1H1, H1H3 and H1H4) was the lowest among four groups which were classified by different types of diplotypes. Those results suggested that the NLRP3 gene was significantly associated with susceptibility to digestive disorders in rabbit.

Function identification of bovine Nramp1 promoter and intron 1

  • Hao, Linlin;Zhang, Libo;Li, Mingtang;Nan, Wang;Liu, Songcai;Zhong, Jifeng
    • Animal cells and systems
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    • v.15 no.3
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    • pp.227-233
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    • 2011
  • The Nramp1/Slc11a1 locus encodes a proton-coupled divalent cation transporter, expressed in late endosomes/lysosomes of macrophages, that constitutes a component of the innate immune response to combat intracellular pathogens and it was shown to play an important role in regulating inherent immunity. The previously identified Z-DNA forming polymorphic repeat(GT)n in the promoter region of the human Nramp1 gene does act as a functional polymorphism influencing gene expression. Research has shown that INF-${\gamma}$, TNF-${\alpha}$, IL-$1{\beta}$ and bacteria LPS increase the level of Nramp1 expression. However, the molecular mechanism for Nramp1 gene regulation is unclear. In this research, bovine Nramp1 5'-flanking region (-1748~+769) was cloned and analyzed by bioinformatics. Then to find the core promoter and the cis-acting elements, deletion analysis of promoter was performed using a set of luciferase reporter gene constructs containing successive deletions of the bovine Nramp1 5'-flanking regions. Promoter activity analysis by the dual luciferase reporter assay system showed that the core promoter of Nramp1 was located at +58~-89 bp. Some positive regulatory elements are located at -89~-205 bp and -278~-1495 bp. And the repressor elements were in region -205~-278 bp, intron1 and -1495~-1748 bp. LPS-responsive regions were located at -1495~-1748 bp and -278~-205 bp. The present study provides an initial effort to explore the molecular mechanism of transcriptional activation of the bovine Nramp1 gene and should facilitate further studies to decode the complex regulatory process and for molecular breeding for disease resistance in bovines.

Variable localization of Toll-like receptors in human fallopian tube epithelial cells

  • Amjadi, Fatemehsadat;Zandieh, Zahra;Salehi, Ensieh;Jafari, Reza;Ghasemi, Nasrin;Aflatoonian, Abbas;Fazeli, Alireza;Aflatoonian, Reza
    • Clinical and Experimental Reproductive Medicine
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    • v.45 no.1
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    • pp.1-9
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    • 2018
  • Objective: To determine the localization, expression, and function of Toll-like receptors (TLRs) in fallopian tube epithelial cells. Methods: The localization of TLRs in fallopian tube epithelial cells was investigated by immunostaining. Surprisingly, the intensity of staining was not equal in the secretory and ciliated cells. After primary cell culture of fallopian tube epithelial cells, ring cloning was used to isolate colonies of ciliated epithelial cells, distinct from non-ciliated epithelial cells. The expression of TLRs 1-10 was examined by quantitative real-time polymerase chain reaction, and protein localization was confirmed by immunostaining. The function of the TLRs was determined by interleukin (IL)-6 and IL-8 production in response to TLR2, TLR3, TLR5, TLR7, and TLR9 ligands. Results: Fallopian tube epithelial cells expressed TLRs 1-10 in a cell-type-specific manner. Exposing fallopian tube epithelial cells to TLR2, TLR3, TLR5, TLR7, and TLR9 agonists induced the secretion of proinflammatory cytokines such as IL-6 and IL-8. Conclusion: Our findings suggest that TLR expression in the fallopian tubes is cell-type-specific. According to our results, ciliated cells may play more effective role than non-ciliated cells in the innate immune defense of the fallopian tubes, and in interactions with gametes and embryos.

Anticancer Effect of Activated Natural Killer Cells on Human Colorectal Tumor (결장암에 대한 활성 자연살해세포의 항암효능)

  • Sung, Hye-Ran;Kim, Jee-Youn;Park, Min-Gyeong;Kim, Il-Hoi;Lee, Dong-Wook;Han, Sang-Bae;Lee, Chong-Kil;Song, Suk-Gil
    • YAKHAK HOEJI
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    • v.54 no.3
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    • pp.192-199
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    • 2010
  • Colorectal cancer is one of the most common alimentary malignancies. In this study, the antitumor activity of activated human natural killer (NK) cells against human colorectal cancer was evaluated in vivo. Human NK cells are the key contributors of innate immune response and the effective functions of these cells are enhanced by cytokines. Human peripheral blood mononuclear cells (PBMC) were cultured with interleukin-2 (IL-2)-containing medium for 14 days and resulted in enriched NK cell population. The resulting populations of the cells comprised 7% $CD3^+CD4^+$ cells, 25% $CD3^+CD8^+$ cells, 13% $CD3^-CD8^+$ cells, 4% $CD3^+$CD16/$CD56^+$ cells, 39% $CD3^+$CD16/$CD56^-$ cells, and 52% $CD3^-$CD16/$CD56^+$ cells. Tumor necrosis factor alpha (TNF-$\alpha$), interferon gamma (IFN-$\gamma$), IL-2, IL-4, and IL-5 transcripts of the activated NK cells were confirmed by RT-PCR. In addition, activated NK cells at doses of 2.5, 5 and 10 million cells per mouse inhibited 10%, 34% and 47% of SW620-induced tumor growth in nude mouse xenograft assays, respectively. This study suggests that NK cell-based immunotherapy may be used as an adoptive immunotherapy for colorectal cancer patients.

Ursodeoxycholic Acid Inhibits Inflammatory Cytokine Expression in THP-1 Cells Infected with Aggregatibacter actinomycetemcomitans

  • Song, YuRi;Kim, SeYeon;Park, Mee Hee;Na, Hee Sam;Chung, Jin
    • International Journal of Oral Biology
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    • v.42 no.1
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    • pp.33-38
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    • 2017
  • Background: Periodontitis is an inflammatory disease characterized by the breakdown of tooth-supporting tissues, leading to tooth loss. Aggregatibacter actinomycetemcomitans are major etiologic bacterium causing aggressive periodontitis. Ursodeoxycholic acid (UDCA), a hydrophilic gall bladder acid, has been used as an effective drug for various diseases related to immunity. The aim of this study was to investigate the effect of UDCA on the inflammatory response induced by A. actinomycetemcomitans. Methods: A human acute monocytic leukemia cell line (THP-1) was differentiated to macrophage- like cells by treatment with phorbol 12-mystristate 13-acetate (PMA) and used for all experiments. The cytotoxic effect of UDCA was examined by MTT assay. THP-1 cells were pretreated with UDCA for 30 min before A. actinomycetemcomitans infection and the culture supernatant was analyzed for various cytokine production by ELISA. The effect of UDCA on bacterial growth was examined by measuring optical densities using a spectrophotometer. Results: UDCA showed no cytotoxic effect on THP-1 cells, up to $80{\mu}M$ Ed highlight: Please confirm technical meaning. UDCA pretreatment inhibited the A. actinomycetemcomitans-induced $IL-1{\beta}$, $TNF-{\alpha}$, and IL-17A secretion in a dose-dependent manner. UDCA also inhibited IL-21 production at $60{\mu}M$. The production of IL-12 and IL-4 was not influenced by A. actinomycetemcomitans infection. Conclusion: These findings indicate that UDCA inhibits the production of inflammatory cytokines involved in innate and Th17 immune responses in A. actinomycetemcomitans-infected THP-1- derived macrophages, which suggests its possible use for the control of aggressive periodontitis.

Globular Adiponectin Exerts a Pro-Inflammatory Effect via IκB/NF-κB Pathway Activation and Anti-Inflammatory Effect by IRAK-1 Downregulation

  • Lee, Kyoung-Hee;Jeong, Jiyeong;Woo, Jisu;Lee, Chang-Hoon;Yoo, Chul-Gyu
    • Molecules and Cells
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    • v.41 no.8
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    • pp.762-770
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    • 2018
  • Adiponectin, a hormone produced by adipose tissue, is very abundant in plasma, and its anti- and pro-inflammatory effects are reported. However, the mechanisms of these pro- and anti-inflammatory effects are not fully defined. Herein, we evaluated the dual inflammatory response mechanism of adiponectin in macrophages. Short-term globular adiponectin (gAd) treatment induced $I{\kappa}B{\alpha}$ degradation, $NF-{\kappa}B$ nuclear translocation, and $TNF-{\alpha}$ production in RAW 264.7 cells. Polymyxin B pretreatment did not block gAd-induced $I{\kappa}B{\alpha}$ degradation, and heated gAd was unable to degrade $I{\kappa}B{\alpha}$, suggesting that the effects of gAd were not due to endotoxin contamination. gAd activated IKK and Akt, and inhibition of either IKK or Akt by dominant-negative $IKK{\beta}$ ($DN-IKK{\beta}$) or DN-Akt overexpression blocked gAd-induced $I{\kappa}B{\alpha}$ degradation, suggesting that short-term incubation with gAd mediates inflammatory responses by activating the $I{\kappa}B/NF-{\kappa}B$ and PI3K/Akt pathways. Contrastingly, long-term stimulation with gAd induced, upon subsequent stimulation, tolerance to gAd, lipopolysaccharide, and CpG-oligodeoxynucleotide, which is associated with gAd-induced downregulation of IL-receptor-associated kinase-1 (IRAK-1) due to IRAK-1 transcriptional repression. Conclusively, our findings demonstrate that the pro- and anti-inflammatory responses to gAd in innate immune cells are time-dependent, and mediated by the activation of the $I{\kappa}B/NF-{\kappa}B$ pathway, and IRAK-1 downregulation, respectively.