• Proceedings of the Korea Crystallographic Association Conference
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• 2003.05a
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• pp.13-13
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• 2003

B-cell activating factor (BAFF) is a key regulator of B-lymphocyte development. Its biological role is mediated by the specific receptors BCMA, TACI, and BAFF-R. We have determined the crystal structure of BAFF-R extracellular domain bound to BAFF at a resolution of 3.3 ?. The cysteine-rich domain(CRD) of the BAFF-R extracellular domain adopts a b-hairpin structure and binds to the virus-like BAFF cage in a 1:1 molar ratio. The conserved DxL motif of BAFF-R is located on the tip of the b-turn, and plays an indispensable role in the binding of BAFF. The crystal structure shows that a unique dimeric contact occurs between the BAFF-R monomers in the virus-like cage complex. Both of the CRDs of TACI contain the DxL motifs and simultaneously interact with the BAFF dimer in the virus-like cage.

• IMMUNE NETWORK
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• v.11 no.4
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• pp.196-202
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• 2011

Background: B cell-activating factor belonging to the TNF family (BAFF) is primarily expressed by macrophages and dendritic cells, and stimulates B cell proliferation, differentiation, survival, and Ig production. In the present study, we explored the effect of activin A on BAFF expression by APCs. Methods: To investigate the effect of activin A on BAFF expression by mouse APCs, we measured the level of BAFF expression at the transcriptional and protein levels using RT-PCR and ELISA. Results: Activin A markedly enhanced BAFF expression in mouse macrophages and dendritic cells at both the transcriptional and protein levels. SB431542, an activin receptor-like kinase 4 (ALK4) inhibitor, completely abrogated activin A-induced BAFF transcription. Furthermore, overexpression of DN-Smad3 abolished activin-induced BAFF expression at the transcriptional and protein levels. Conclusion: These results demonstrate that activin A can enhance BAFF expression through ALK4-Smad3 pathway.

• 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.

• IMMUNE NETWORK
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• v.12 no.3
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• pp.84-88
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• 2012

B cell-activating factor belonging to the TNF family (BAFF) is primarily expressed by macrophages and stimulates B cell proliferation, differentiation, survival, and Ig production. In this study, we explored the effect of lactoferrin (LF) on BAFF expression by murine macrophages. We determined the level of BAFF expression at the transcriptional and protein levels using RT-PCR and ELISA, respectively. LF markedly enhanced BAFF expression in mouse macrophages at both the transcriptional and protein levels. Overexpression of Smad3/4 further increased LF-induced BAFF transcription while DN-Smad3 abolished the LF-induced BAFF expression. These results demonstrate that LF can enhance BAFF expression through Smad3/4 pathway.

• 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.

• 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.

• 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.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.5
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• pp.2389-2394
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• 2016

Background: Multiple myeloma (MM) is influenced by genetic and micro-environmental changes. Malignant plasma cells produce an abnormal monoclonal immunoglobulin, as well as cytokines, such as IL-10 and IL-6 which stimulate cells of the bone marrow microenvironment (BMM) and cause dysfunction and failure of many organs. B cell activating factor (BAFF), IL6, IL10 are known to influence the growth & survival of the malignant clone. Aim: The objectives of the present study were to investigate the circulating levels of BAFF, IL-10 and IL-6, correlate them with well-known parameters of disease activity in patients with MM, and to detect their impact on the patients' survival. Materials and Methods: This study was conducted on 89 newly diagnosed MM patients and seventy apparently healthy volunteers as a normal control group. BAFF, IL6, IL10 were measured by ELISA for both groups. Survival analysis was performed for all patients. Results: Studied markers were higher in the MM patients compared to the normal control subjects. Patients' survival was improved by high serum BAFF levels. Conclusions: High levels of BAFF were found to improve patients' survival. BAFF and IL-6 can be considered probable diagnostic markers for MM.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.3
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• pp.1351-1355
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• 2016

Background: Multiple myeloma (MM) is influenced by genetic and micro-environmental changes. Malignant plasma cells produce an abnormal monoclonal immunoglobulin, as well as cytokines, such as IL-10 and IL-6 which stimulate cells of the bone marrow microenvironment (BMM) and cause dysfunction and failure of many organs. B cell activating factor (BAFF), IL6 and IL10 are known to influence the growth and survival of malignant clones. Aim: The objectives of the present study were to investigate the circulating levels of BAFF, IL-10 and IL-6, correlate them with well-known parameters of disease activity in patients with MM, and to detect their impact on patients' survival. Materials and Methods: This study was conducted on 89 newly diagnosed MM patients and seventy apparently healthy volunteers as a normal control group. BAFF, IL6, IL10 were measured by ELISA for both groups and survival analysis was performed for all patients. Results: Studied markers were higher in the MM patients compared to the normal control subjects. Patients survival was improved by high serum BAFF levels. Conclusions: High levels of BAFF were found to improve patients' survival. BAFF and IL-6 can be considered probable diagnostic markers for MM.

• IMMUNE NETWORK
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• v.10 no.5
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• pp.173-180
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• 2010

Background: APRIL, originally known as a cytokine involved in B cell survival, is now known to regulate the inflammatory activation of macrophages. Although the signal initiated from APRIL has been demonstrated, its role in cellular activation is still not clear due to the presence of BAFF, a closely related member of TNF superfamily, which share same receptors (TACI and BCMA) with APRIL. Methods: Through transfection of siRNA, BAFF-deficient THP-1 cells (human macrophage-like cells) were generated and APRIL-mediated inflammatory activities were tested. The expression patterns of APRIL were also tested in vivo. Results: BAFF-deficient THP-1 cells responded to APRIL-stimulating agents such as monoclonal antibody against APRIL and soluble form of TACI or BCMA. Furthermore, co-incubation of the siBAFF-deficient THP-1 cells with a human B cell line (Ramos) resulted in an activation of THP-1 cells which was dependent on interactions between APRIL and TACI/BCMA. Immunohistochemical analysis of human pathologic samples detected the expression of both APRIL and TACI in macrophage-rich areas. Additionally, human macrophage primary culture expressed APRIL on the cell surface. Conclusion: These observations indicate that APRIL, which is expressed on macrophages in pathologic tissues with chronic inflammation, may mediate activation signals through its interaction with its counterparts via cell-to-cell interaction.