Impact of interleukin-21 in the pathogenesis of primary Sjogren's syndrome: increased serum levels of interleukin-21 and its expression in the labial salivary glands

Kang, Kwi Young,Kim, Hyun-Ok,Kwok, Seung-Ki,Ju, Ji Hyeon,Park, Kyung-Su,Sun, Dong-Il,Jhun, Joo Yeon,Oh, Hye Jwa,Park, Sung-Hwan,Kim, Ho-Youn BioMed Central 2011 ARTHRITIS RESEARCH AND THERAPY Vol.13 No.5

<P><B>Introduction</B></P><P>Interleukin (IL)-21 is a cytokine that controls the functional activity of effector T helper cells and the differentiation of Th17 cells, and promotes B-cell differentiation. To test whether IL-21 participates in the pathogenesis of primary Sjögren's syndrome (SS), serum IL-21 level was measured and IL-21 expression in the labial salivary glands (LSG) was examined.</P><P><B>Methods</B></P><P>Serum IL-21 levels in 40 primary SS, 40 rheumatoid arthritis (RA), and 38 systemic lupus erythematosus (SLE) patients and 20 healthy controls were measured. Serum IL-21 levels of SS patients were assessed for correlations with laboratory data, including anti-nuclear antibody, anti-Ro/La antibodies, globulin, immunoglobulin (Ig) class, and IgG subclass. LSGs from 16 primary SS and 4 controls with sicca symptoms were evaluated for IL-21 and IL-21 receptor (IL-21R) expression by immunohistochemistry. Confocal microscopy was performed to further characterize the IL-21 positive cells.</P><P><B>Results</B></P><P>Primary SS patients had significantly higher serum IL-21 levels than controls, and these increments correlated positively with levels of IgG, IgG1. Serum IgG1 levels correlated with anti-Ro antibody titers. Immunohistochemical analyses showed that lymphocytic foci and the periductal area of the LSGs from SS patients expressed high levels of IL-21 and lower levels of IL-21R, whereas the control LSGs showed minimal expression of both antigens. The more the lymphocyte infiltrated, IL-21expression in LSGs showed a tendency to increase. Confocal microscopic analyses revealed that IL-21 expressing infiltrating lymphocytes in the LSGs of SS patients also expressed CXCR5.</P><P><B>Conclusions</B></P><P>Primary SS is associated with high serum IL-21 levels that correlate positively with serum IgG, especially IgG1, levels. The expression of IL-21 is increased as more lymphocytes infiltrated in LSGs. These observations suggest that IL-21 may play an important role in primary SS pathogenesis.</P>

금은화, 연교, 포공영 혼합물의 항염증 작용에 관한 연구

최강민 ( Kang Min Choi ),전주현 ( Ju Hyun Jeon ),김은석 ( Eun Seok Kim ),성기정 ( Ki Jung Sung ),김영일 ( Young Il Kim ) 대전대학교 한의학연구소 2021 혜화의학회지 Vol.30 No.1

Objective : The purpose of this study is to investigate the inflammatory-control effects of Cheonghyeol-antidote complex(Lonicera japonica Thunberg, Forsythia viridissima Lindley, and Taraxacum platycarpum H. Dahlstedt complex, CHA) in LPS-induced RAW264.7 cell and mouse inflammation models. Method : For in vitro and in vivo experiment, Indicators such as cell viability, mRNA expression level(iNOS, IL-6, IL-1β, COX-2, TNF-a), Inflammatory factor production(NO, IL-6, IL-1β, TNF-a), and protein phosphorylation level(ERK, JNK, p38) were analyzed. For in vivo experiment, Indicators such as mRNA expression level(iNOS, IL-6, IL-1β, COX-2, TNF-a), Inflammatory factor production(IL-6, IL-1β, TNF-a), protein phosphorylation level(ERK, JNK, p38) and immune cell(white blood cell, lymphocyte) were analyzed. Results : 1. In vitro experiment In cell viability of CHA, CHA showed cell viability below 90% at concentrations of 400 μg / ml or more. In mRNA expression level, IL-6 and IL-1β showed a significant decrease at all concentrations except 25 μg / ml concentration, and iNOS, COX-2, and TNF-a showed a significant decrease at all concentrations of CHA compared to the control group. In inflammatory factor production, NO and TNF-a showed a significant decrease at all concentrations except 25 μg / ml concentration of CHA, and IL-1β showed a significant decrease at 100, 200 μg / ml concentration of CHA compared to the control group. IL-6 showed a significant decrease at all concentration of CHA compared to the control group. In protein phosphorylation level, ERK and p38 showed a significant decrease at all concentrations except 25 μg / ml concentration of CHA and JNK showed a significant decrease at all concentrations of CHA compared to control group. 2. In vivo experiment In mRNA expression level, iNOS, COX-2 and TNF-a showed a significant decrease in all administration groups of CHA compared to the control group. In Inflammatory factor production, IL-6, IL-1β and TNF-a showed a significant decrease in all the administration groups of CHA. In protein phosphorylation level, ERK, JNK, and p38 showed a significant decrease in all the administration groups of CHA. In the immune cells, leukocytes and lymphocytes showed a significant decrease in all the administration groups of CHA. Conclusions : This study shows that CHA has antioxidant and inflammatory-control effects on LPS-induced RAW264.7 cells. It is hoped that further research will be conducted on the individual mechanisms of Lonicera japonica Thunberg, Forsythia viridissima Lindley, and Taraxacum platycarpum H. Dahlstedt.

Positive and negative roles of interleukin-6 in bone metabolism , inflammation and cell differentiation : application in oriental medical research

Lee, Dong Kyu,Kang, Dong Hwi,Kim, Dong Il,Lee, Tae Kyun,Park, Young Guk,Kim, Cheorl Ho 대한한의학회 부인과학회 2000 大韓韓方婦人科學會誌 Vol.13 No.2

Interleukin 6 (IL-6)은 여러종류의 세포에서 분화 및 주화인자로 작용하는 사이토카인이다. 사람 IL-6의 분자구조는 21에서 28 kDa의 분자량을 갖는 하나의 폴리펩타이드 단백질로서 N-형과 O-형당부가반응과 세린잔기에 인산화를 수반하여 수식되어 있다. 이 사이토카인은 수성의 28-아미노산 자기로 구성된 시그날배열을 가진 212 아미노산의 전구체 단백질로서 생합성된다. IL-6와 가장 밀접한 분자구조를 갖는 물질로는 granulocyte colony-stimulating factor (G-CSF)가 있으며 사람 IL-6의 유전자는 염색체 7p21에 암호화되어 있다. IL-6는 IL-6수용체 (80 kDa subunit, IL-6Ra)의 a-사슬의 세포의 영역과 상호작용을 거쳐 세포표면에 결합하게 되며 이렇게 생성된 결합체는 gp130수용체와 상호작용하며, 이때 gp130 subunit는 JAK/STAT signaling cascade의 계속적인 활성화능력을 보유하도록 리간드-의존적인 2량화 형성이 유도된다. IL-6Ra의 세포내 영역도메인은 신호전달반응에 아무런 역할을 하지 않으며 IL-6Ra의 세포막통과와 세포질도메인이 결여된 수용성 IL-6수용체도 마찬가지로 IL-6와 반웅하며 상승제로서 가능을 하게 된다. 이러한 광범위한 발현과 효과 때문에 IL-6생성의 생체내에서의 부적절한 발현과 조절은 중요한 생리적인 변화를 야기시킨다. 본 총설에서는 생리적이고 병태생리적인 조건에서의 IL-6의 역할과 기능을 검토하였으며 한의학에서의 면역, 천식, 골대사, 당뇨, 암, 순환기계질환, 신경계질환의 약물개발과 기전해석의 수단으로서 검토하였다. Interleukin 6 (IL-6) is a cytokine that functions as a trophic and differentiating factor in cells of many types. Human IL-6 is a single-chain protein with a molecular mass ranging from 21 to 28 kDa. IL-6 is modified by N- and O-glycosylations, as well as by phosphorylation on serine residues. The cytokine is synthesized as a precursor protein of 212 amino acids with a hydrophobic 28-residue signal sequence. Its closest homolog is granulocyte colony-stimulating factor (G-CSF). The gene for human IL-6 is located on chromosome 7p21. IL-6 binds to the cell surface via an interaction with the extracellular region of the a-chain of the IL-6 receptor (80 kDa subunit, IL-6Ra). This complex then associates with the gp130 receptor. The gpl30 subunit undergoes ligand-dependent dimerization with subsequent activation of the JAK/STAT signaling cascade. The intracellular domain of IL-6Ra does not play a role in signal transduction. The soluble IL-6 receptor, which lacks the transmembrane and cytoplasmic domain of IL-6Ra, is also responsive to IL-6 and acts as an agonist. Because of its wide-ranging expression and effects, the inappropriate expression and modulation of IL-6 production has important physiological consequences. Presently, it was examined that role of IL-6 under physiological and pathophysiological conditions, and its feasibility as a drug discovery target are meaningful in fields of oriental medical research.

인간 재조합 인터루긴-32 면역조절작용에 대한 유세포 분석

이광수,김영관,채정일,심정현,김은미,강형식,김수현,윤도영,명평근 충남대학교 생물공학연구소 2006 생물공학연구지 Vol.12 No.-

Xenotransplantation of porcine organs has the potential to overcome the severe shortage of human tissues and organ available for human transplantation. however, it remains various hurdles for clinical xenotransplantation. In pig and mouse xenotransplantation, porcine xenograft evoke a strong cellular rejection response in immunocompetent host and grafts are destroyed within a week. This cellular immune response could involved both T cells and NK cells. A number of groups have shown that human NK cells can recognize and damage porcine endothelial cells. In addition, human T cells can respond to porcine endothelial cells through both direct and indirect mechanisms. Cellular rejection of porcine tissues requires T cells, particularly CD4^(+) cells. A new cytokine recombinant human interleukin-32α,β(IL-32α,β) has a role innate and acquired immune system. In order to investigate the role of recombinant mouse IL-18 and recombinant human IL-32α,β in xenograft rejection, we transplanted the PK(15) cells to C57BL/6 mice with or without intraperitoneal injection of recombinant mouse IL-18 or recombinant human IL-32 α,β. It was analyzed the population of NK cell, T cell and B cell in the C57BL/6 mice transplanted with PK(15) cells and recombinant mouse IL-18 or recombinant human IL-32α,β by flow cytometry analysis. As a result, lymph node and thymus of PK15/IL18, PK15/IL32α and PK15/IL32β injected group were increased to T cell activation population than normal injected groups. CD8^(+) T cells were decreased in lymph node of PK15/IL18, PK15/IL32α and PK15/IL32β injected groups. CD4^(+) T cells were increased in lymph node cell of PK15/IL32α and PK15/IL32β injected group and also, B cell population were increased in lymph node cell and spleen of PK15/IL18, PK15/IL32α and PK15/IL32β injected group. Therefore, we suggest that recombinant mouse IL-18 and recombinant human IL-32α,β suppress xenograft rejection in cellular xenotransplantation.

위암에서 Helicobacter pylori cagA, vacA, iceA 유전자와 숙주 Interleukin-1β및 Interleukin-1 수용체 길항제 유전자 다형성

이성훈 ( Seong Hun Lee ),김태오 ( Tae Oh Kim ),이동현 ( Dong Hyun Lee ),박원일 ( Won Il Park ),김광하 ( Gwang Ha Kim ),허정 ( Jeong Heo ),강대환 ( Dae Hwan Kang ),송근암 ( Geun Am Song ),조몽 ( Mong Cho ) 대한내과학회 2006 대한내과학회지 Vol.71 No.1

Background: Both Helicobacter pylori (H. pylori) cagA, vacA, iceA genotype and host IL-1B/IL-1RN polymorphisms play a role in determining the clinical consequences of H. pylori infection. This study aimed to investigate whether there might be any combinations of H. pylori cagA, vacA, iceA genotype and host IL-1B/IL-1RN polymorphisms that are particularly associated with the occurrence of gastric carcinoma in Korean patients. Methods: This study population was comprised of 239 patients with H. pylori infection: 122 with gastric carcinoma and 117 with gastritis only. DNA was isolated from gastric biopsy sample and H. pylori cagA, vacA and iceA genotype were determined by PCR. IL-1B-511 polymorphisms were genotyped by PCR-RFLP and IL-1RN polymorphisms were analyzed with variable number of tandom repeat after PCR. Results: H. pylori cagA, vacA, and iceA genotype were not associated with an increased risk for gastric carcinoma. IL-1B-511*T carriers and IL-1RN*2 carriers did not show increased risk for gastric carcinoma. On combination of bacterial/host genotypes, cagA+/IL-1B-511*T carriers and cagA+/IL-1RN*2 carriers, vacA s1/IL-1B-511*T carriers, vacA s1/IL-1RN*2 carriers, vacA m1/IL-1B-511*T carriers, vacA m1/IL-1RN*2 carriers, iceA1/IL-1B-511*T carriers, iceA1/IL-1RN*2 carriers showed no increased risk of gastric carcinoma. Conclusions: Combined H. pylori cagA, vacA, iceA genotype and host IL-1B/IL-1RN polymorphisms shows no increased risk of gastric carcinoma. Therefore, it seems other endogenous or exogenous factors may play more important role in the development of gastric carcinoma in Korean.(Korean J Med 71:24-37, 2006)

The enhanced IL-l8 production by UVB irradiation requires ROI and AP-1 signaling in human keratinocyte cell line (HaCaT)

Cho, Daeho,Kang, Jae Seung,Park, Jong Hoon,Kim, Young-In,Hahm, Eunsil,Lee, Junechul,Yang, Yoolhee,Jeon, Junho,Song, HyunKeun,Park, Hyunjeong,Kim, Taesung,Pang, Saic,Kim, Chul-Woo,Hwang, Young Il,Lee, 전남대학교 약품개발연구소 2002 약품개발연구지 Vol.11 No.-

Based on our recent observation that enhanced IL-18 expression positively correlates with malignant skin tumors, such as SCC and melanoma, we examined the possible role of UVB, known to be associated with skin cancer development, in the enhancement of IL-18 production using primary human epidermal keratinocytes and human cell line HaCaT. After cells were exposed to UVB irradiation in vitro, IL-18 production was examined by Northern blot analysis and ELISA, and it was found that IL-18 production is enhanced by UVB irradiation in a dose- and time-dependent manner. In addition, we confirmed that it is functionally active form of IL-18 using the inhibitor of caspase-1. The effect of UVB irradiation was blocked by antioxidant, N-acetyl-ι-cysteine (NAC), which suggested the involvement of reactive oxygen intermediates (ROI) in the signal transduction of UVB irradiation-enhanced IL-18 synthesis. We also found that UVB irradiation increased AP-1 binding activity by using EMSA with AP-1-specific oligonucleotide. Furthermore, inhibitors of UVB-induced AP-1 activity, such as PD98059, blocked enhanced IL-18 production, indicating that AP-1 activation is required for UVB-induced IL-18 production. Taken together, our results suggest that UVB irradiation-enhanced IL-18 production is selectively mediated through the generation of ROI and the activation of AP-1.

IL-17A induces osteoblast differentiation by activating JAK2/STAT3 in ankylosing spondylitis

Jo, Sungsin,Wang, Sung Eun,Lee, Young Lim,Kang, Suman,Lee, Bitnara,Han, Jinil,Sung, Il-Hoon,Park, Ye-Soo,Bae, Sang-Cheol,Kim, Tae-Hwan BioMed Central 2018 Arthritis research & therapy Vol.20 No.-

<P><B>Background</B></P><P>IL-17A has recently emerged as a potential target that regulates the extensive inflammation and abnormal bone formation observed in ankylosing spondylitis (AS). Blocking IL-17A is expected to inhibit bony ankylosis. Here, we investigated the effects of anti IL-17A agents in AS.</P><P><B>Methods</B></P><P>TNFα, IL-17A, and IL-12/23 p40 levels in serum and synovial fluid from patients with ankylosing spondylitis (AS), rheumatoid arthritis (RA), osteoarthritis (OA), or healthy controls (HC) were measured by ELISA. Bone tissue samples were obtained at surgery from the facet joints of ten patients with AS and ten control (Ct) patients with noninflammatory spinal disease. The functional relevance of IL-17A, biological blockades, Janus kinase 2 (JAK2), and non-receptor tyrosine kinase was assessed in vitro with primary bone-derived cells (BdCs) and serum from patients with AS.</P><P><B>Results</B></P><P>Basal levels of IL-17A and IL-12/23 p40 in body fluids were elevated in patients with AS. JAK2 was also highly expressed in bone tissue and primary BdCs from patients with AS. Furthermore, addition of exogenous IL-17A to primary Ct-BdCs promoted the osteogenic stimulus-induced increase in ALP activity and mineralization. Intriguingly, blocking IL-17A with serum from patients with AS attenuated ALP activity and mineralization in both Ct and AS-BdCs by inhibiting JAK2 phosphorylation and downregulating osteoblast-involved genes. Moreover, JAK2 inhibitors effectively reduced JAK2-driven ALP activity and JAK2-mediated events.</P><P><B>Conclusions</B></P><P>Our findings indicate that IL-17A regulates osteoblast activity and differentiation via JAK2/STAT3 signaling. They shed light on AS pathogenesis and suggest new rational therapies for clinical AS ankylosis.</P><P><B>Electronic supplementary material</B></P><P>The online version of this article (10.1186/s13075-018-1582-3) contains supplementary material, which is available to authorized users.</P>

Two-Track Medical Treatment Strategy According to the Clinical Scoring System for Chronic Rhinosinusitis

Kim, Dong-Kyu,Kang, Seong Il,Kong, Il Gyu,Cho, Young Hoon,Song, Seul Ki,Hyun, Se Jin,Cho, Sung Dong,Han, Sang-Yoon,Cho, Seong-Ho,Kim, Dae Woo The Korean Academy of Asthma, Allergy and Clinical 2018 Allergy, Asthma & Immunology Research Vol.10 No.5

<P><B>Purpose</B></P><P>The previously reported Japanese clinical scoring study (JESREC) suggests that chronic rhinosinusitis (CRS) can be divided into 4 subtypes according to the degree of eosinophilic CRS (ECRS) and offers the information regarding the prognosis of CRS to clinicians. However, this scoring system has not yet been validated by an immunological study and needs to provide treatment guidelines based on underlying immunologic profiles. We investigated the immunologic profile of each CRS subgroup according to the JESREC classification and suggest its clinical application.</P><P><B>Methods</B></P><P>A total of 140 CRS patients and 20 control subjects were enrolled. All patients were classified into 4 groups according to the JESREC (non-, mild, moderate and severe ECRS). Nasal tissues were analyzed for mRNA expression of major cytokines (IL-5, IL-10, IL-13, IL-17A, IL-22, IL-23p19, IFN-γ, periostin, thymic stromal lymphopoietin [TSLP] and ST2), major chemokines (CCL11, CCL24, CXCL1 and CXCL2), transcription factors (T-bet, GATA3, RORC and FOXP3) and COL1A1 for type I collagen. Protein levels of 3 major cytokines (IL-5, IL-17A and IFN-γ) were also measured by multiplex immunoassay. Principal component analysis (PCA) was conducted to investigate the overall profile of multiple mediators.</P><P><B>Results</B></P><P>The moderate/severe ECRS showed up-regulation of type 2-related mediators (IL-5, IL-13, periostin, TSLP and ST-2), whereas INF-γ (type 1 cytokine) and CXCL1 (neutrophil chemokine) expressions were increased in non-/mild ECRS compared with moderate/severe ECRS. The JESREC classification reflected an immunological endotype. In PCA data, PCA1 indicates a relative type 2 profile, whereas PCA2 represents a type 1/type 17-related profile. In this analysis, mild ECRS was indistinguishable from non-ECRS, whereas moderate to severe ECRS showed a distinct distribution compared with non-ECRS. The JESREC classification could be divided into 2 categories, non-/mild vs. moderate/severe ECRS based on underlying immunological analyses.</P><P><B>Conclusions</B></P><P>The CRS clinical scoring system from the JESREC study reflects an inflammatory endotype. However, the immunologic profile of mild ECRS was similar to that of non-ECRS. Therefore, we propose type 2-targeted medical treatment for moderate to severe ECRS and type 1/type 17-targeted for non-ECRS and mild ECRS as the first treatment option.</P>

Acetyl salicylic acid inhibits Th17 airway inflammation via blockade of IL-6 and IL-17 positive feedback

문형근,Chil Sung Kang,최준표,최동식,Hyun Il Choi,최용욱,전성규,유주연,Myoung Ho Jang,고용송,김윤근 생화학분자생물학회 2013 Experimental and molecular medicine Vol.45 No.1

T-helper (Th)17 cell responses are important for the development of neutrophilic inflammatory disease. Recently, we found that acetyl salicylic acid (ASA) inhibited Th17 airway inflammation in an asthma mouse model induced by sensitization with lipopolysaccharide (LPS)-containing allergens. To investigate the mechanism(s) of the inhibitory effect of ASA on the development of Th17 airway inflammation, a neutrophilic asthma mouse model was generated by intranasal sensitization with LPS plus ovalbumin (OVA) and then challenged with OVA alone. Immunologic parameters and airway inflammation were evaluated 6 and 48 h after the last OVA challenge. ASA inhibited the production of interleukin (IL)-17 from lung T cells as well as in vitro Th17 polarization induced by IL-6. Additionally, ASA, but not salicylic acid, suppressed Th17 airway inflammation,which was associated with decreased expression of acetyl-STAT3 (downstream signaling of IL-6) in the lung. Moreover, the production of IL-6 from inflammatory cells, induced by IL-17, was abolished by treatment with ASA, whereas that induced by LPS was not. Altogether, ASA, likely via its acetyl moiety, inhibits Th17 airway inflammation by blockade of IL-6 and IL-17positive feedback.

N-Acetyl-L-Cysteine에 의한 생쥐 골수유래 가지세포의 기능적 활성화 저해

정영주(Young-joo Jeong),맹형건(Hyung Gun Maeng),김민규(Min Kyu Kim),강재승(Jae Seung Kang),이왕재(Wang Jae Lee),황영일(Young-il Hwang) 대한해부학회 2008 Anatomy & Cell Biology Vol.41 No.2

N-acetyl-L-cysteine (NAC)은 thiol기를 포함하는 화합물로서, glutathione (GSH)의 전구체로 작용하여 포유류 세포 내에서 항산화제로 작용한다. 또한 항염기능이 있으며 호산구나 B세포, 가지세포 (dendritic cell, DC)와 같은 면역세포 들에 여러 가지 영향을 미치는 것으로 알려져 있다. 특히 가지세포에 작용하여 활성화를 억제하거나 가지세포에 의한 Th2 반응 유도에 관여한다고 알려져 있다. 그러나 이들 연구는 세부적인 사항에 있어서 그 결과가 서로 상치하는바가 많으며, 또한 조절T세포의 관점에서는 연구된 바가 없다. 따라서 본 연구에서는 NAC 처리가 가지세포 활성화에 미치는 영향을 재확인하였고, NAC 처리된 가지세포의 T세포 활성 능력 저하, 또는 Th2 반응 유도 여부를 알아보았다. 활성화 시 가지세포에서 증가하는 활성산소기 (reactive oxygen species)는 NAC 처리로 낮아져서, NAC이 가지세포에 항산화작용을 나타냄을 확인하였다. NAC 처리로 가지세포에서 보조자극인자인 CD40과 CD86의 발현이 저해되었으며, 활성화 시 정상적으로 낮아지는 포식기능은 처리된 NAC의 농도에 비례하게 보존되었다. 활성화 시 분비되는 IL-6, IL-10, IL-12는 모두 감소하였다. 이러한 NAC-DC와 함께 배양한 T세포의 증식이나 Th1 cytokine인 IFN-γ, Th2 cytokine인 IL-5의 분비가 모두 저하되어 Th1/Th2의 편중 없이 가지세포의 T세포 자극능력이 전반적으로 감소하였음을 나타내었다. 또한 T세포 배양액에서 IL-10과 TGF-β의 농도 역시 NAC-DC로 자극된 경우에 현저히 줄어서, NAC-DC에 의한 T세포 증식 감소 등은 조절T세포 유도에 의한 것이 아니라 T세포 무반응이 유도된 때문임을 나타내 주었다. N-acetyl-L-cysteine (NAC) is a thiol-containing compound and acts as a precursor for glutathione (GSH). It behaves as an antioxidant in mammalian cells and also exerts anti-inflammatory effects. NAC is also known to affect several immune cells including eosinophils, B cells, T cells, and dendritic cells (DC) in many aspects. Even though it has been reported that NAC inhibits DC activation and shifts the immune response to Th2, these studies exhibit some contradictory results in detail and do not give any information with respect to the induction of regulatory T cells. In this study, we re-analyzed the effects of NAC on DC during their activation. We also evaluated whether it induced T cell anergy, Th1/Th2 shift, or regulatory T cells. NAC suppressed the elevation of intracellular reactive oxygen species during DC activation. In parallel, it down-regulated surface expression of CD40 and CD86, suppressed the decrease of phagocytic function, lowered the secretion of cytokines such as IL-6, IL-10, and IL-12. All these effects showed dose-dependency. Thus, it seems likely that NAC inhibited DC activation with regard to their phenotype and cytokine secretion. When we evaluated the T cell-stimulating capacity of these NAC-DC, T cell proliferation and secretion of both Th1 (IFN-γ) and Th2 cytokine (IL-5) were decreased. This implies that the T cell-stimulating activity of NAC-DC decreased without any shift to Th1 or Th2 cytokine (IL-5). The secretion of IL-10 and TGF-β in the supernatants were also decreased, which suggests that the decrease of T cell proliferation and cytokine secretion is due to the induction of T cell anergy, rather than regulatory T cells.