• Title/Summary/Keyword: B cell activating factor

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Single Cell Transcriptomic Re-analysis of Immune Cells in Bronchoalveolar Lavage Fluids Reveals the Correlation of B Cell Characteristics and Disease Severity of Patients with SARS-CoV-2 Infection

  • Chae Won Kim;Ji Eun Oh;Heung Kyu Lee
    • IMMUNE NETWORK
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    • v.21 no.1
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    • pp.10.1-10.13
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    • 2021
  • The coronavirus disease 2019 (COVID-19) pandemic (severe acute respiratory syndrome coronavirus 2) is a global infectious disease with rapid spread. Some patients have severe symptoms and clinical signs caused by an excessive inflammatory response, which increases the risk of mortality. In this study, we reanalyzed scRNA-seq data of cells from bronchoalveolar lavage fluids of patients with COVID-19 with mild and severe symptoms, focusing on Ab-producing cells. In patients with severe disease, B cells seemed to be more activated and expressed more immunoglobulin genes compared with cells from patients with mild disease, and macrophages expressed higher levels of the TNF superfamily member B-cell activating factor but not of APRIL (a proliferation-inducing ligand). In addition, macrophages from patients with severe disease had increased pro-inflammatory features and pathways associated with Fc receptor-mediated signaling, compared with patients with mild disease. CCR2-positive plasma cells accumulated in patients with severe disease, probably because of increased CCL2 expression on macrophages from patients with severe disease. Together, these results support the hypothesis that different characteristics of B cells might be associated with the severity of COVID-19 infection.

Platelet-Activating Factor Enhances Experimental Pulmonary Metastasis of Murine Sarcoma Cells by Up-regulation of Matrix Metalloproteinases-9 Through NF-$\kappa$B-Dependent Pathway

  • Ko, Hyun-Mi;Back, Hae-Kyong
    • Biomedical Science Letters
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    • v.10 no.2
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    • pp.143-151
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    • 2004
  • Matrix metalloproteinases (MMPs) are capable of degrading extracellular matrix, a process that is necessary for angiogenesis, tumor invasion and metastasis. Platelet-activating factor (PAP) increases angiogenesis, tumor growth and metastasis through nuclear factor (NF)-$\kappa$B activation. Based on these facts, the involvement of MMPs in PAF-induced pulmonary metastasis was investigated in murine sarcoma cells, MMSV-BALB/3T3. Messenger RNA expression and enzymatic activity of MMP-9 were assessed by RT-PCR and zymography, and cell migration and metastasis were done for the detection of MMP-9 functional activity. PAP induced mRNA expression and enzymatic activity of MMP-9, and its effects were either inhibited by the PAP antagonist, WEB 2170 or by the NF-$\kappa$B inhibitor, parthenolide, or p65 antisense oligonucleotide in a dose-dependent manner. In addition, PAF induced promoter activity of MMP-9, which was inhibited by WEB 2170, phenanthroline, NAC, PDTC. These results indicate that PAF induces mRNA expression and enzymatic activity of MMP-9 in NF-$\kappa$B dependent manner. Cell migration assay showed that PAF induced MMSV-BALB/3T3 migration, and its effect was significantly inhibited by treatment with phenanthroline. PAF enhanced pulmonary metastasis of murine sarcoma cells, MMSV-BALB/3T3 was also reduced by phenanthroline. These results suggest that PAF-enhanced cell migration and pulmonary metastasis is mediated through the expression of MMP. In conclusion, It is suggested that PAF enhances pulmonary metastasis by inducing MMP-9 expression via the activation of NF-$\kappa$B.

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Expression of B Cell Activating Factor Pathway Genes in Mouse Mammary Gland

  • Choi, S.;Jung, D.J.;Bong, J.J.;Baik, M.
    • Asian-Australasian Journal of Animal Sciences
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    • v.20 no.2
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    • pp.153-159
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    • 2007
  • In our previous study, overexpression of extracellular proteinase inhibitor (Expi) gene accelerated apoptosis of mammary epithelial cells, and induced expression of B cell activating factor (BAFF) gene. In this study, we found induction of BAFF-receptor (BAFF-R) gene expression in the Expi-transfected cells. A proliferation-inducing ligand (APRIL) gene is another TNF family member and the closest known relative of BAFF. We found induction of APRIL gene expression in the Expi-overexpressed apoptotic cells. NF-${\kappa}$B gene was also induced in the Expi-overexpressed cells. Expression patterns of BAFF and APRIL pathway-related genes were examined in in vivo mouse mammary gland at various reproductive stages. Expression levels of BAFF gene were very low at early pregnancy, increased from mid-pregnancy, and peaked at lactation, and thereafter decreased at involution stages of mammary gland. Expression of BAFF-R gene was highly induced in involution stages compared to lactation stages. Thus, expression patterns of BAFF-R gene were correlated to apoptotic status of mammary gland: active apoptosis of mammary epithelial cells occurs at involution stage of mammary gland. Expression levels of NF-${\kappa}$B gene were higher in involution stages compared to lactation stages. We analyzed mRNA levels of bcl-2 family genes from different stages of mammary development. Bcl-2 gene expression was relatively constant during lactation and involution stages. There was a slight increase in bcl-xL gene expression in involution stages compared to lactation state. Bax gene expression was highly induced in involution stage. Our results suggest that signaling pathways activated by both BAFF and ARRIL in mammary gland point towards NF-${\kappa}$B activation which causes upregulation of bax.

Increased B cell-activating factor (BAFF) level in the sputum of children with asthma

  • Jee, Hye-Mi;Choi, Bong-Seok;Kim, Kyung-Won;Sohn, Myung-Hyun;Han, Man-Yong;Kim, Kyu-Earn
    • Clinical and Experimental Pediatrics
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    • v.53 no.8
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    • pp.795-800
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    • 2010
  • Purpose: B cell-activating factor (BAFF) is a tumor-necrosis factor (TNF) superfamily member best known for its role in the survival and maturation of B cells. BAFF activity is observed in naive cells as well as in effector/memory T cells. We aimed to explore whether BAFF in sputum is expressed at elevated levels in asthmatic airways and associated with eosinophilic inflammation, pulmonary function, and bronchial hyperresponsiveness in children. Methods: One hundred and fifty-four asthmatic children and 98 healthy children were enrolled in the study. Sputum supernatants were collected and sputum BAFF and eosinophil cationic protein (ECP) levels were measured. We performed pulmonary function tests and methacholine challenge tests, while measuring total eosinophil count, total serum IgE, and serum ECP in all subjects. Results: Asthmatic children had significantly higher levels of BAFF in induced sputum [26.50 (10.50-100.27) pg/mL] compared to healthy children [18.32 (7.68-44.63) pg/mL; $P$=0.011]. Sputum BAFF positively correlated with sputum eosinophils (${\gamma}$=0.406, $P$<0.001) and sputum ECP (${\gamma}$=0.789, $P$<0.001). Significant negative correlations were found between sputum BAFF and FEV1 (${\gamma}$=-0.291, $P$<0.001) or post-bronchodilator FEV1 (${\gamma}$=-0.334, $P$<0.001), whereas nonsignificant correlations were found between sputum BAFF and bronchial hyperresponsiveness, serum eosinophil count, and serum ECP. Conclusion: These findings suggest that BAFF may play a role in childhood asthma, and BAFF levels in sputum could be a supportive marker that represents airway inflammation, especially eosinophilic inflammation.

Reactive Oxygen Species-Induced Expression of B cell Activating Factor (BAFF) Is Independent of Toll-like Receptor 4 and Myeloid Differentiation Primary Response Gene 88

  • Kim, Hyun-Sun;Moon, Eun-Yi
    • Biomolecules & Therapeutics
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    • v.17 no.2
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    • pp.144-150
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    • 2009
  • Reactive oxygen species play a role in signal transduction and in many human diseases. B-cell activating factor (BAFF) plays a role for mature B cell generation and maintenance and for the incidence of autoimmune diseases. We previously reported that BAFF expression was induced by ROS. In this study, we investigated whether ROS-induced BAFF expression was affected by toll-like receptor (TLR) 4 or myeloid differentiation primary response gene (MyD) 88. BAFF expression was increased by serum deprivation that is an experimental modification to produce ROS. In contrast, TLR4 and MyD88 were decreased by serum deprivation. Although ROS production was decreased in TLR4-nonfunctional or MyD88-deficient splenocytes as compared to that in control mice, serum deprivation increased ROS production and augmented BAFF expression in both cells. $50{\mu}M\;H_2O_2$ also increased BAFF expression in TLR4-deficient or MyD88-deficient splenocytes. Collectively, results show that BAFF expression may be mediated by TLR4 or MyD88-independent manner and TLR4 or MyD88 may not be required in BAFF expression.

Synovial Cell Migration is Associated with B Cell Activating Factor Expression Increased by TNFα or Decreased by KR33426

  • Lee, Jiyoung;Yoon, Sung Sik;Thuy, Pham Xuan;Moon, Eun-Yi
    • Biomolecules & Therapeutics
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    • v.28 no.5
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    • pp.405-413
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    • 2020
  • Fibroblast-like synoviocytes (FLS) play a crucial role in initiating rheumatoid arthritis. B-cell activating factor (BAFF) plays a role in FLS survival as well as in B cell maturation and maintenance. Here, we investigated whether tumor necrosis factor (TNF)-α-induced BAFF expression controls FLS migration and whether BAFF expression in FLS could be regulated by KR33426 which is the inhibitor of BAFF binding to BAFF receptors (BAFF-R) by using MH7A synovial cells transfected with the SV40 T antigen. More TNF-α-treated cells migrated compared to the control. TNF-α increased BAFF expression in FLS, significantly. FLS migration was inhibited by the transfection with BAFF-siRNA. KR33426 also inhibited BAFF expression increased by TNF-α treatment in FLS as judged by western blotting, PCR, and transcriptional activity assay. Kinases including JNK, p38 and Erk were activated by TNF-α treatment. While JNK and p38 were inhibited by KR33426 treatment, no changes in Erk were observed. Transcription factors including p65, c-Fos, CREB and SP1 were enhanced by TNF-α treatment. Among them, c-Fos was inhibited by KR33426 treatment. Small interference(si)-RNA of c-fos decreased BAFF transcriptional activity. FLS migration induced by TNF-α was inhibited by the transfection with BAFF-siRNA. KR33426 increased Twist, Snail, Cadherin-11 and N-Cadherin. In contrast, KR33426 decreased E-cadherin and TNF-α-enhanced CCL2. Taken together, our results demonstrate that synovial cell migration via CCL2 expression could be regulated by BAFF expression which is decreased by KR33426 and c-Fos-siRNA. It suggests for the first time that the role of BAFF-siRNA on FLS migration might be matched in the effect of KR33426 on BAFF expression.

Nuclear Factor-κB Activation: A Question of Life or Death

  • Shishodia, Shishir;Aggarwal, Bharat B.
    • BMB Reports
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    • v.35 no.1
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    • pp.28-40
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    • 2002
  • Apoptosis is a mode of cell death that plays an important role in both pathological and physiological processes. Research during the last decade has delineated the entire machinery needed for cell death, and its constituents were found to pre-exist in cells. The apoptotic cascade is triggered when cells are exposed to an apoptotic stimulus. It has been known for several years that inhibitors of protein synthesis can potentiate apoptosis that is induced by cytokines and other inducers. Until 1996, it was not understood why protein synthesis inhibitors potentiate apoptosis. Then three reports appeared that suggested the role of the transcription factor NF-${\kappa}B$ activation in protecting the cells from TNF-induced apoptosis. Since then several proteins have been identified that are regulated by NF-${\kappa}B$ and are involved in cell survival, proliferation, and protection from apoptosis. It now seems that when a cell is attacked by an apoptotic stimulus, the cell responds first by activating anti-apoptotic mechanisms, which mayor may not be followed by apoptosis. Whether or not a cell undergoes proliferation, the survival, or apoptosis, appears to involve a balance between the two mechanisms. Inhibitors of protein synthesis seem to suppress the appearance of protein that are involved in anti-apoptosis. The present review discusses how NF-${\kappa}B$ controls apoptosis.

Extracellular S100A4 negatively regulates osteoblast function by activating the NF-κB pathway

  • Kim, Haemin;Lee, Yong Deok;Kim, Min Kyung;Kwon, Jun-Oh;Song, Min-Kyoung;Lee, Zang Hee;Kim, Hong-Hee
    • BMB Reports
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    • v.50 no.2
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    • pp.97-102
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    • 2017
  • Patients with inflammatory bone disease or cancer exhibit an increased risk of fractures and delayed bone healing. The S100A4 protein is a member of the calcium-binding S100 protein family, which is abundantly expressed in inflammatory diseases and cancers. We investigated the effects of extracellular S100A4 on osteoblasts, which are cells responsible for bone formation. Treating primary calvarial osteoblasts with recombinant S100A4 resulted in matrix mineralization reductions. The expression of osteoblast marker genes including osteocalcin and osterix was also suppressed. Interestingly, S100A4 stimulated the nuclear factor-kappaB (NF-${\kappa}B$) signaling pathway in osteoblasts. More importantly, the ex vivo organ culture of mouse calvariae with recombinant S100A4 decreased the expression levels of osteocalcin, supporting the results of our in vitro experiments. This suggests that extracellular S100A4 is important for the regulation of bone formation by activating the NF-${\kappa}B$ signaling pathway in osteoblasts.

Innate Immunity Activation and Anti-Inflammation Effects of Evodia Rutaecarpine Water Extract (오수유 물 추출물의 선천 면역 활성과 염증 억제 효과)

  • Jeong, So-Mi;Lee, Jin-Moo;Lee, Chang-Hoon;Hwang, Deok-Sang;Jang, Jun-Bock
    • The Journal of Korean Obstetrics and Gynecology
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    • v.34 no.2
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    • pp.1-15
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    • 2021
  • Objectives: This study was designed to examine immuno-modulatory effects of Evodia Rutaecarpine by activating innate immune system and inhibiting inflammation. Methods: First, Cell cytotoxicity was examined with 4T1 breast carcinoma and TG-induced macrophage. To investigate activating innate immune system of Evodiamine Rutacarpine Extract (ERE) on macrophage, we tested tumor necrosis factor-alpha (TNF-α), interleukin-12 (IL-12), and interleukin-6 (IL-6). In addition, TNF-α and nitric oxide (NO) induced by lipopolysaccharide (LPS) were measured after treating with ERE to observe innate immune modulating effect of ERE on RAW 264.7 cell. Also, mitogen-activated protein kinase (MAPK) and nuclear factor κB (NF-κB) were examined by western blot analysis. Results: In cytotoxicity analysis, ERE significantly affected tumor cell growth above specific concentration. Also, ERE significantly affected macrophage growth above specific concetration. As compared with the control group, the production of TNF-α, IL-12 and IL-6 were increased in TG-induced macrophage. As compared with the control group, TNF-α and IL-6 were significantly up-regulated in RAW 264.7 cell. The expression of TNF-α and NO induced by LPS after treating ERE was significantly decreased compared with control group. In addition, We observed ERE inhibited the phosphorylation levels of p-extracellular signal-regulated kinase (p-ERK), p-Jun N-terminal kinase (p-JNK), and p-p38 in western blotting by treating ERE on RAW 264.7 cell. Conclusions: ERE seems to have considerable impact on the anti-cancer effect by activation of innate immune system and inflammation control.

Lipoteichoic Acid from Lactobacillus plantarum Inhibits the Expression of Platelet-Activating Factor Receptor Induced by Staphylococcus aureus Lipoteichoic Acid or Escherichia coli Lipopolysaccharide in Human Monocyte-Like Cells

  • Kim, Hangeun;Jung, Bong Jun;Jeong, Jihye;Chun, Honam;Chung, Dae Kyun
    • Journal of Microbiology and Biotechnology
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    • v.24 no.8
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    • pp.1051-1058
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    • 2014
  • Platelet-activating factor receptor (PAFR) plays an important role in bacterial infection and inflammation. We examined the effect of the bacterial cell wall components lipopolysaccharide (LPS) and lipoteichoic acid (LTA) from Lactobacillus plantarum (pLTA) and Staphylococcus aureus (aLTA) on PAFR expression in THP-1, a monocyte-like cell line. LPS and aLTA, but not pLTA, significantly increased PAFR expression, whereas priming with pLTA inhibited LPS-mediated or aLTA-mediated PAFR expression. Expression of Toll-like receptor (TLR) 2 and 4, and CD14 increased with LPS and aLTA treatments, but was inhibited by pLTA pretreatment. Neutralizing antibodies against TLR2, TLR4, and CD14 showed that these receptors were important in LPS-mediated or aLTA-mediated PAFR expression. PAFR expression is mainly regulated by the nuclear factor kappa B signaling pathway. Blocking PAF binding to PAFR using a PAFR inhibitor indicated that LPS-mediated or aLTA-mediated PAF expression affected TNF-${\alpha}$ production. In the mouse small intestine, pLTA inhibited PAFR, TLR2, and TLR4 expression that was induced by heat-labile toxin. Our data suggested that pLTA has an anti-inflammatory effect by inhibiting the expression of PAFR that was induced by pathogenic ligands.