• IMMUNE NETWORK
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• 제8권3호
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• pp.75-81
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• 2008

Background: Platelets take part in repairing the lesions of endothelial damage. To understand the molecular mechanism of this process, we tested the hypothesis that CD154 expressed on activated platelets stimulates proliferation of human endothelial cells. Methods: The expression levels of CD154 and CD40 on platelets and endothelial cells, respectively, were measured by flow cytometry and confocal microscopy. Function-blocking monoclonal antibody against CD154 was developed after immunization with CD154-transfected L cells. Results: An anti-CD40 agonist antibody and soluble CD154 both induced significant proliferation of endothelial cells. In addition, a function-blocking anti-CD154 antibody inhibited the platelet-induced proliferation of endothelial cells, indicating that the CD154-CD40 pathway is involved in these cellular interactions. An anti-VEGF antibody failed to inhibit the proliferation. This, in addition to the fact that very small amounts of VEGF are released from platelets or endothelial cells, suggests that VEGF does not play an important role in the platelet-stimulated proliferation of endothelial cells. Conclusion: Our results indicate that platelets induce proliferation of endothelial cells by CD154-CD40 interactions independently of VEGF.

• Journal of Microbiology and Biotechnology
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• 제17권12호
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• pp.1955-1964
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• 2007

A recent report showed that analysis of CD154 expression in the presence of the secretion inhibitor Brefeldin A (Bref A) could be used to assess the entire repertoire of antigen-specific $CD4^+\;T$ helper cells. However, the capacity of intracellular CD154 expression to identify antigen-specific $CD8^+\;T$ cells has yet to be investigated. In this study, we compared the ability of intracellular CD154 expression to assess antigen-specific $CD8^+\;T$ cells with that of accepted standard assays, namely intracellular cytokine IFN-${\gamma}$ staining (ICS) and MHC class I tetramer staining. The detection of intracellular CD154 molecules in the presence of Bref A reflected the kinetic trend of antigen-specific $CD8^+\;T$ cell number, but unfortunately showed less sensitivity than ICS and tetramer staining. However, ICS levels peaked and saturated 8 h after antigenic stimulation in the presence of Bref A and then declined, whereas intracellular CD154 expression peaked by 8 h and maintained the saturated level up to 24 h post-stimulation. Moreover, intracellular CD154 expression in antigen-specific $CD8^+\;T$ cells developed in the absence of $CD4^+\;T$ cells changed little, whereas the number of IFN-${\gamma}$-producing $CD8^+\;T$ cells decreased abruptly. These results suggest that intracellular CD154 could aid the assessment of antigen-specific $CD8^+\;T$ cells, but does not have as much ability to identify heterogeneous $CD4^+\;T$ helper cells. Therefore, the combined analytical techniques of ICS and tetramer staining together with intracellular CD154 assays may be able to provide useful information on the accurate phenotype and functionality of antigen-specific $CD8^+\;T$ cells.

• Journal of Oral Medicine and Pain
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• 제34권4호
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• pp.363-369
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• 2009

미란형 구강편평태선과 재발성 아프타성 구내염은 T림프구에 의해 매개되는 염증성 면역질환이다. T림프구에 영향을 주는 다양한 조절 인자들 중 CD28, CD45, CD152, CD154, CD279등의 mRNA가 미란형 구강편평태선 및 재발성 아프타성 구내염 환자들의 비자극성 전타액내에서 어떻게 발현되는지를 살펴보고, 이것의 진단학적 가치를 평가하고자 한다. 미란형 구강편평태선으로 진단받은 환자군 18명, 재발성 아프타성 구내염으로 진단받은 환자군 12명, 정상군 8명에게서 비자극성 전타액을 10분간 채득한 후, 상피세포를 분리하여 mRNA를 추출하였다. Real time PCR을 이용하여 각 군의 T림프구 조절 인자들의 mRNA 발현 양상을 비교분석하였다. 미란형 구강편평태선의 T림프구 조절인자들의 mRNA 발현 양상은 정상인과 비교 결과, CD45, CD279는 높게 측정되었고, CD154는 낮게 측정되었다. 재발성 아프타성 구내염 환자들의 T림프구 조절인자들의 mRNA 발현 양상은 정상인과 비교 결과, CD45, CD279는 높게 발현되었고, CD28, CD154는 낮게 발현되었다. 부가적으로 미란형 구강편평태선 환자군의 타액내 CD152의 발현 양상은 재발성 아프타성 구내염 환자군보다 높게 발현되었다. 미란형 구강편평태선과 재발성 아프타성 구내염 환자들의 비자극성 전타액내 T림프구 조절인자들의 mRNA 발현 양상은 각 질환의 진단에 기여할 수 있을 것으로 사료된다.

• IMMUNE NETWORK
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• 제13권6호
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• pp.264-274
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• 2013

The unrestricted population of $CD4^+Foxp3^+$ regulatory T (Treg) cells, which have been known to control the expression of autoimmune diseases and protective immunity to inflammatory reactions, has led to greater appreciation of functional plasticity. Detecting and/or isolating Ag-specific $CD4^+Foxp3^+$ Tregs at the single cell level are required to study their function and plasticity. In this study, we established and compared both MHC class II tetramer and intracellular CD154 staining, in order to detect $CD4^+Foxp3^+$ Treg specific for foreign Ag in acute and chronic infections with lymphocytic choriomeningitis virus (LCMV). Our results revealed that MHC class II tetramer staining showed a lower detection rate of LCMV $GP_{66-77}$-specific $CD4^+$ T cells because most of MHC class II tetramers were unbound and unstable when combined staining was performed with intracellular cytokines. In contrast, intracellular CD154 staining was revealed to be easier and simple for detecting LCMV $GP_{66-77}$-specific $CD4^+$ T cells, compared to MHC class II tetramer staining. Subsequently, we employed intracellular CD154 staining to detect LCMV $GP_{66-77}$-specific $CD4^+Foxp3^+$ Tregs using $Foxp3^{GFP}$ knock-in mouse, and found that LCMV $GP_{66-77}$-specific $CD4^+Foxp3^+$ Tregs and polyclonal $CD4^+Foxp3^+$ Tregs showed differential expansion in mice infected with LCMV Arms or Cl13 at acute (8 and 13 days pi) and chronic phases (35 days pi). Therefore, our results provide insight into the valuable use of intracellular CD154 staining to detect and characterize foreign Ag-specific $CD4^+Foxp3^+$ Treg in various models.

• Clinical and Experimental Reproductive Medicine
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• 제37권3호
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• pp.231-237
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• 2010

목 적: 반복적 유산 또는 반복적 착상실패 환자의 T 림프구의 Th1 면역반응 정도를 알아보고, T 림프구 활성 정도를 분석하고자 하였다. 연구방법: 반복적 유산 및 반복적 착상실패를 경험한 37명의 환자를 연구군으로 설정하고, 유산이나 불임의 병력이 없이 정상분만의 경력이 있는 11명의 가임 여성을 대조군으로 모집하였다. 유세포분석기를 이용하여, 이들의 말초혈액 중 T helper 세포 내 TNF-$\alpha$와 INF-$\gamma$ 및 IL-10의 발현도를 측정하고 Th1/Th2 세포 비율 (TNF-$\alpha$/IL-10 및 INF-$gamma$/IL-10 발현도)을 계산하여 Th1 면역반응의 우세 정도 및 T 림프구의 활성도를 분석하였으며, 활성 표지자인 CD154와 CD69 발현 정도를 비교하였다. 결 과: 연구군의 평균연령은 $35.3{\pm}4.3$세였으며, 이들에서 T helper cell 내 TNF-$\alpha$/IL-10의 발현 비율이 대조군에 비해 유의하게 높았고 ($42.1{\pm}2.3$ vs. $28.7{\pm}2.7$, p=0.002), CD154와 CD69의 발현율 또한 대조군에 비해 전반적으로 높았다. CD154의 경우, T helper cell ($1.7{\pm}0.5$ vs. $0.3{\pm}0.2$, p=0.038)과 T suppressor cell ($0.6{\pm}0.2$ vs. $0.1{\pm}0.0$, p=0.024) 모두에서 유의하게 높은 발현을 보인 반면, CD69의 경우, 전체 T 림프구 ($5.6{\pm}1.9$ vs. $1.3{\pm}5.4$, p=0.046)와 T suppressor cell ($4.8{\pm}1.3$ vs. $1.8{\pm}0.2$, p=0.035)에서 통계적으로 높은 발현을 확인할 수 있었다. 결 론: 반복적 유산 및 반복적 착상실패를 보이는 여성에서 T 림프구의 활성도와 Th1 면역반응이 증가하였으며 이는, 이들 여성에서 활성화된 T 림프구가 Th1 면역반응을 유도하여 초기 임신의 유지와 착상에 좋지 않은 영향을 미치기 때문으로 생각된다.

• IMMUNE NETWORK
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• 제4권3호
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• pp.143-154
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• 2004

Background: CD27 is recently known as a memory B cell marker and is mainly expressed in activated T cells, some B cell population and NK cells. CD27 is a member of tumor necrosis factor receptor family. Like CD40 molecule, CD27 has (P/S/T/A) X(Q/E)E motif for interacting with TNF receptor-associated factors (TRAFs), and TRAF2 and TRAF5 bindings to CD27 in 293T cells were reported. Methods: To investigate the CD27 signaling effect in B cells, human CD40 extracellular domain containing mouse CD27 cytoplamic domain construct (hCD40-mCD27) was transfected into mouse B cell line CH12.LX and M12.4.1. Results: Through the stimulation of hCD40-mCD27 molecule via anti-human CD40 antibody or CD154 ligation, expression of CD11a, CD23, CD54, CD70 and CD80 were increased and secretion of IgM was induced, which were comparable to the effect of CD40 stimulation. TRAF2 and TRAF3 were recruited into lipid-enriched membrane raft and were bound to CD27 in M12.4.1 cells. CD27 stimulation, however, did not increase TRAF2 or TRAF3 degradation. Conclusion: In contrast to CD40 signaling pathway, TRAF2 and TRAF3 degradation was not observed after CD27 stimulation and it might contribute to prolonged B cell activation through CD27 signaling.

• IMMUNE NETWORK
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• 제3권3호
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• pp.176-181
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• 2003

Background: The molecular basis of follicular dendritic cells (FDC)-germinal center (GC) B cell interaction is largely unknown, although this cellular interaction is thought to be important for the whole process of GC B cell differentiation. Methods: Using FDC-like cells, HK, and highly purified GC B cells, we attempted to identify the molecules that play critical roles in the interactions between FDC and B cells. GC B cells were co-cultured with HK cells and soluble CD154 in the presence or absence of various function-blocking monoclonal antibodies to examine their effect on GC B cell binding to HK cells and B cell proliferation. Results: Anti-CD11a and anti-CD54 antibodies inhibited GC B cell binding to HK cells while anti-CD49d and anti-CD106 antibodies did not. GC B cell proliferation was not impaired by the disruption of GC B cell-HK cell adherence. Conclusion: Our results suggest that CD11a/CD18-CD54 interactions play an important roles in the initial binding of GC B cells to FDC and diffusible growth factors from FDC may be responsible the massive proliferation of GC B cells.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.656-659
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• 2001

Cyclodextrin glucanotransferase (CGTase) (EC 2.4.1.19) use starch to produce cyclic maltooligosaccharides (cyclodextrins, CDs) which are of interest in various applications. To obtain a novel CGTase having high CD-forming activity, ${\beta}-cyclodextrin$ glucanotransferase $({\beta}-CGTase)$ from Bacillus firmus var. alkalophilus was modified through site-directed mutagenesis and constructed five mutants, H59T, H59Q, Y96M, 9O-PPI-93, and ${\Delta}(148-154)D$, respectively. Y96M and ${\Delta}(148-154)D$ showed much higher level of conversion yields of starch into CDs from 28.6% to about 39% compared to wild-type ${\beta}-CGTase$, respectively, but 90-PPI-93 maintained similar convesion yields of starch to CDs. And their ${\beta}-CD$ ratios to total CDs were not changed and maintained, and convesion yields to linear maltooligosaccharides of all mutants were not changed significantly. These results indicates that five mutations of ${\beta}-CGTase$ from Bacillus firmus var. alkalophilus appears to be important roles for increase of overall CD production rather than change of its product specificity, especially.

• Biomolecules & Therapeutics
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• 제29권2호
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• pp.154-165
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• 2021

This study aimed to investigate whether the antidiabetic drugs dipeptidyl peptidase 4 (DPP4) inhibitors such as evogliptin and sitagliptin affect the membrane DPP4 (mDPP4) enzymatic activity and immune function of T helper1 (Th1) cells in terms of cytokine expression and cell profiles. The mDPP4 enzymatic activity, cytokine expression, and cell profiles, including cell counts, cell viability, DNA synthesis, and apoptosis, were measured in pokeweed mitogen (PWM)-activated CD4+CD26+ H9 Th1 cells with or without the DPP4 inhibitors, evogliptin and sitagliptin. PWM treatment alone strongly stimulated the expression of mDPP4 and cytokines such as interleukin (IL)-2, IL-10, tumor necrosis factor-alpha, interferon-gamma, IL-13, and granulocyte-macrophage colony stimulating factor in the CD4+CD26+ H9 Th1 cells. Evogliptin or sitagliptin treatment potently inhibited mDPP4 activity in a dose-dependent manner but did not affect either the cytokine profile or cell viability in PWM-activated CD4+CD26+ H9 Th1 cells. These results suggest that, following immune stimulation, Th1 cell signaling pathways for cytokine expression function normally after treatment with evogliptin or sitagliptin, which efficiently inhibit mDPP4 enzymatic activity in Th1 cells.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2005년도 총회 및 춘계학술발표회
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• pp.151-154
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• 2005

Laboratory column experiments for simultaneous removal of Cd and Cr(VI) are conducted using newly developed material, referred to as Fe-loaded zeolite, which has both reduction ability of iron and ion exchange ability of zeolite. Breakthrough curves were obtained from each column experiment, and described with advection-dispersion equation. Apparent parameters including $K_{app}\;and\;D_{app}$ were newly introduced for effectively describing the Cr(VI) breakthrough curve. $K_{app}$ decreased with increasing initial contaminant concentration and with decreasing flow rates. Whereas, $D_{app}$ were not significantly affected by initial contaminant concentration or flow rate.