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>

도시공원 범죄예방을 위한 CPTED 인증평가기준 정립에 관한 연구

김강일(Kang Il Kim),조준택(Joon Tag Cho),박현호(Hyeon Ho Park) 한국셉테드학회 2018 한국셉테드학회지 Vol.9 No.1

도시지역에서의 공원이란 시민들의 건강과 휴양 그리고 정서생활에 도움을 주고 녹지를 확보하여 환경에 도움을 주는 공간이다. 하지만 누구에게나 개방되어 있는 도시 공원의 특성상 공간의 안전을 위협하는 소수의 위협들은 다수의 이용자인 시민들에게 불편함을 주거나 위협을 초래하는 경우가 발생한다. 이와 관련하여 각종 선행 연구들은 공원에서 범죄가 빈번하게 발생하고, 시민들의 휴식공간이라는 공원의 제 기능을 다 하지 못하고 있다는 문제를 지적하고 있다. 특히 최근 많은 관심을 받고 있는 사회적 약자를 대상으로 한 범죄에 대응하기 위한 도시공원의 설계 관리가 중요함을 일관되게 강조하고 있다. 이에 이 연구에서는 CPTED의 기본이론을 토대로 도시공원의 범죄예방과 관련된 선행 연구를 분석하여 도시공원에 적합한 CPTED 요소를 추출하고 도시공원의 방범환경 인증평가 체크리스트를 개발하였다. 이러한 체크리스트를 바탕으로 크기별, 종류별 공원 5곳을 선정하여 실제 현장 조사를 실시하고 안전요소를 분석하여 최종 체크리스트를 도출하였다. 이 체크리스트의 최종평가분야는 관리운영, 감시, 접근통제, 영역성, 활동성 지원 CPTED요소를 기반으로 하고 이에 더하여 안내표지, 방범 및 안전시설, 가점항목으로 설정하였으며 각각의 세부평가항목으로 구성하였다. 이 연구에서 개발한 체크리스트의 평가기준은 모든 공원에 대한 범죄예방 인증평가를 수행할 수 있도록 하는 범용 체크리스트로 이러한 평가기준은 다양한 규모와 형태를 가진 공원들의 특성을 고려하여 평가와 인정의 기본원칙에 의거하여 다양한 형태로 변형되어 활용할 수 있도록 하였다. 이와 관련하여 범죄위험을 예방하는데 있어 중요한 분야의 핵심 항목들에 대해서는 높게 배점하고 정성적인 평가에 의해 배점을 차등적으로 주도록 하였다. 또한 신규 공원뿐만 아니라 기존에 있던 공원들도 적극적 개선을 통해 인정을 받게 하고자 하는 취지로 만들어 전체적인 공원 안전개선을 위한 기반이 되도록 하였다. 본 체크리스트는 경찰청이 범죄예방진단팀(CPO)을 통해 시행 중인 도시공원의 범죄예방우수시설 인증사업에 활용하고 있다. Urban public parks are supposed to be the places for citizens’ rest, healing and public health. However, as public parks are usually open for 24 hours almost every day they are often exposed to criminal attacks within the realm of the space. The crime problem therefore threatens the public safety and security. Previous studies on public parks and crime safety continuously indicate that urban parks are vulnerable to crime and disorder and became the cause of fear of crime due to poor environmental design and planning in terms of CPTED. In this context the researchers have developed a checklist for accreditation/certification of urban public parks for crime prevention by analyzing the examples applying the CPTED principles in public parks and reflecting the field survey results in South Korea. In regard to the item and point, the crucial points for public parks rated highly and the grading was differentiated by qualitative evaluation. In addition, basic principles for certification of Secure/Safe Public Parks Awards were suggested, including operating a rating system to certify public parks so as to promote efforts for improvement, not awarding the certification to parks if any relevant regulations are violated, applying the evaluation items or points in accordance with the local context. The assessment checklist can be revised and used in various ways according to the regional circumstances and can contribute to the security and safety of public parks. The Police Crime Prevention Officers (CPO) are to utilize this checklist for the Secure Public Parks Certification Awards program in order to enhance the level of security for public parks in major cities in South Korea.

Intracellular IL-4, IL-10, and IFN-gamma levels of leukemic cells and bone marrow T cells in acute leukemia.

Park, Hun Hee,Kim, Myungshin,Lee, Bong-Hee,Lim, Jihyang,Kim, Yonggoo,Lee, Eun Jung,Min, Woo Sung,Kang, Chang Suk,Kim, Won Il,Shim, Sang In,Han, Kyungja Institute for Clinical Science] 2006 Annals of clinical and laboratory science Vol.36 No.1

<P>The quantitative levels of intracellular cytokines IL-4, IL-10, and IFN-gamma (ie, the number of bound PE-conjugated antibody molecules/cell) of leukemic cells and bone marrow T cells (bmT cells) of acute leukemia patients were analyzed by flow cytometry. One hundred, thirty-one (95 AML, 25 ALL, 11 ABL) patients were studied. The leukemic cell IL-4 level was highest in the monocytic AML group (1735 +/- 1056) and lowest in the dysplastic AML group (960 +/- 545). The IFN-gamma level was highest in the acute promyelocytic leukemia (APL) group (495 +/- 159), and lowest in the ALL group (252 +/- 119). The IL-10 level was not significantly different among the diagnosis groups. In bmT cells, the IL-10 level was highest in the dysplastic AML group (972 +/- 1049) and lowest in the APL group (397 +/- 352). The leukemic cell cytokine levels were lowest and bmT cell cytokine levels were highest in the dysplastic AML group. There were no significant correlations of these cytokine levels with 2-yr survival rate, complete remission (CR) rate, or relapse rate. The cytokine levels of bmT cells at the time of CR became normal and were not different among the diagnosis groups. In summary, leukemic cell and bmT cell cytoplasmic expression profiles of IL-4, IL-10, and IFN-gamma are characteristic for each diagnostic group of acute leukemia patients and the profiles of bmT cells are normal at the time of CR.</P>

A Novel Function of Interleukin-10 Promoting Self-Renewal of Hematopoietic Stem Cells

Kang, Young-Ju,Yang, Seung-Jip,Park, Gyeongsin,Cho, Bin,Min, Chang-Ki,Kim, Tae-Yoon,Lee, Joon-Sung,Oh, Il-Hoan Wiley (John WileySons) 2007 Stem Cells Vol.25 No.7

<P>Self-renewal of hematopoietic stem cells (HSCs) is key to their reconstituting ability, but the factors regulating the process remain poorly understood. Here, we show that Interleukin-10 (IL-10), a pleiotropic immune modulating cytokine, can also play a role in regulating HSC self-renewal. First, a quantitative decrease of primitive hematopoietic cell populations, but not more matured cells, was observed in the bone marrows of IL-10 disrupted mice as determined by long-term in vitro cultures or in vivo competitive repopulation assays. In contrast, normal HSCs from 5-fluorouracil treated marrows cultured on the IL-10 secreting stroma displayed an enhanced repopulating activity compared with cells grown on control stroma, with ninefold higher numbers of donor-derived HSCs in the reconstituted recipient marrows. Moreover, limiting dilution transplantation assay demonstrated that exogenous addition of IL-10 in the stroma-free cultures of purified Lin- Sca-1+ c-kit+ cells caused three- to fourfold higher frequencies of HSCs in the 5-day short-term culture without indirect inhibitory effect of IL-10 on tumor necrosis factor-alpha or interferon-gamma secretion. Interestingly, primitive hematopoietic cells, including Lin- Sca-1+ c-kit+ or side population cells, expressed the surface receptor for IL-10, and microenvironmental production of IL-10 was sharply increased in the osteoblasts lining the trabecular regions of the radiation-stressed marrow but not in the steady-state marrows. These results show that IL-10 may be a ligand that can stimulate self-renewal of HSCs to promote their regeneration in addition to being a ligand for immune regulation. Disclosure of potential conflicts of interest is found at the end of this article.</P>

RSV 와 인플루엔자 바이러스 A 형 감염에 의해 천명을 보이는 소아와 천식 소아에서 비인두 흡인액의 Interleukin-5 와 Interleukin-γ 치의 비교

오재원,이하백,김창렬,염명걸,문수지,박일규,강정옥 대한 소아알레르기 및 호흡기학회 1999 소아알레르기 및 호흡기학회지 Vol.9 No.2

목 적 : 호흡기 바이러스 감염은 소아에서 천식을 악화시키는 것으로 잘 알려져 있다. 그러나 영유아기의 천식이나 천명발생에 있어서 호홉기 바이러스의 역할에 대해서는 명확하게 밝혀져 있지 않다. 소아기의 천명이 천식과 달리 하나의 독립된 질환인지, 아니면 같은 질환으로 달리 표현되는 것인지 논란이 되어왔다. 이에 본 저자들은 호흡기 바이러스 감염과 천명과의 상관관계와 기전을 이해하기 위하여 RSV 감염이나 influenza A 바이러스 감염에 의해 천명이 있는 소아와 바이러스가 증명되지 않고 천명이 있는 천식소아에서의 비인두 흡인액의 IL-5와 IFN-γ치를 측정하여 비교하였다. 방 법 : 호흡기 바이러스 감염군 38명(RSV감염군 21명, influenga A virus 감염군 17명), 바이러스가 증명되지 않은 천식환아군 12명, 정상 대조군 16명을 대상으로 double sandwich ELISA를 이용하여 비인두 흡인액에서 IL-5와 IFN-γ치를 측정하여 비교하였다. 결 과 : RSV 감영군에서 비인두 흡인액의 IL-5 평균치가 influenza A 바이러스군의 평균치보다 의미있게 높았으며, 천식군보다도 높은 양상을 보이나 의미있는 차이는 없었다 반면, influenza A 바이러스 감염군의 비인두 흡인액의 IFN-γ치가 RSV군에 비해 의미있게 높았으나 천식환아군이나 정상군에 비해 의미있게 높지는 않았다. 비인두 흡입액에서 IL-5와 IFN-γ치간의 상관관계는 없었다. 결 론 : RSV 감염군은 influenza A 바이러스 감염군에 비해 Th2 반응이 우세한 것으로 추정되며, 반면에 influenza A virus 감염군은 Th1 반응을 보이는 것을 알 수 있다. Background : Infection with respiratory virus has been shown to exacerbate asthma. However, the role of a respiratory virus in the pathogenesis of chronic asthma and/or wheezing in young children has not been clearly defined. And it also has been debated whether virus-induced wheezing in young children is an entity different from allergic asthma, or just a different expression of the same disease. In this study, we attempted to evaluate the importance of eosinophilic inflammation, comparing IL-5 and IFN-γ levels in nasopharyngeal secretions in wheezing children with or without viral infection and the controls. Methods : We compared IL-5 and IFN-γ levels in nasopharyngeal secretions from 38 non-asthmatic wheezing children with viral infections (RSV in 21 children, influenza A virus in 17 children), 12 asthmatic children without viral infections and 16 children as the controls. Results : The present study reported that RSV infection in children induced more releasing of IL-5 in nasopharyngeal secretions than the influenza A virus infected ones and the controls. On the other hand, the releasing of IFN-γ levels in nasopharyngeal secretions from children with influenza A virus infection was significantly higher than those of the children with RSV infection or asthmatic children. Conclusion : RSV infection in children may play a role in the immune response toward a Th2 phenotype as increasing IL-5 secretion in nasopharyngeal secretion. Increased IFN-γ production in response to the influenza A virus infection may be related to the effective Th1 responses.

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.

PLZF⁺ Innate T Cells Support the TGF-β-Dependent Generation of Activated/Memory-Like Regulatory T Cells

Kang, Byung Hyun,Park, Hyo Jin,Park, Hi Jung,Lee, Jae-Il,Park, Seong Hoe,Jung, Kyeong Cheon Korean Society for Molecular and Cellular Biology 2016 Molecules and cells Vol.39 No.6

PLZF-expressing invariant natural killer T cells and CD4 T cells are unique subsets of innate T cells. Both are selected via thymocyte-thymocyte interaction, and they contribute to the generation of activated/memory-like CD4 and CD8 T cells in the thymus via the production of IL-4. Here, we investigated whether $PLZF^+$ innate T cells also affect the development and function of $Foxp3^+$ regulatory CD4 T cells. Flow cytometry analysis of the thymus and spleen from both CIITA transgenic C57BL/6 and wild-type BALB/c mice, which have abundant $PLZF^+$ CD4 T cells and invariant natural killer T cells, respectively, revealed that $Foxp3^+$ T cells in these mice exhibited a $CD103^+$ activated/memorylike phenotype. The frequency of $CD103^+$ regulatory T cells was considerably decreased in $PLZF^+$ cell-deficient $CIITA^{Tg}Plzf^{lu/lu}$ and $BALB/c.CD1d^{-/-}$ mice as well as in an IL-4-deficient background, such as in $CIITA^{Tg}IL-4^{-/-}$ and $BALB/c.IL-4^{-/-}$ mice, indicating that the acquisition of an activated/ memory-like phenotype was dependent on $PLZF^+$ innate T cells and IL-4. Using fetal thymic organ culture, we further demonstrated that IL-4 in concert with TGF-${\beta}$ enhanced the acquisition of the activated/memory-like phenotype of regulatory T cells. In functional aspects, the activated/ memory-like phenotype of Treg cells was directly related to their suppressive function; regulatory T cells of $CIITA^{Tg}PIV^{-/-}$ mice more efficiently suppressed ovalbumin-induced allergic airway inflammation compared with their counterparts from wild-type mice. All of these findings suggest that $PLZF^+$ innate T cells also augmented the generation of activated/memory-like regulation via IL-4 production.

PLZF+ Innate T Cells Support the TGF-beta-Dependent Generation of Activated/Memory-Like Regulatory T Cells

Kyeong-Cheon Jung,Byung Hyun Kang,Hyo Jin Park,Hi Jung Park,Jae-il Lee,Seong Hoe Park 한국분자세포생물학회 2016 Molecules and cells Vol.39 No.6

PLZF-expressing invariant natural killer T cells and CD4 T cells are unique subsets of innate T cells. Both are selected via thymocyte-thymocyte interaction, and they contribute to the generation of activated/memory-like CD4 and CD8 T cells in the thymus via the production of IL-4. Here, we investigated whether PLZF+ innate T cells also affect the development and function of Foxp3+ regulatory CD4 T cells. Flow cytometry analysis of the thymus and spleen from both CIITA transgenic C57BL/6 and wild-type BALB/c mice, which have abundant PLZF+ CD4 T cells and invariant natural killer T cells, respectively, revealed that Foxp3+ T cells in these mice exhibited a CD103+ activated/memory-like phenotype. The frequency of CD103+ regulatory T cells was considerably decreased in PLZF+ cell-deficient CII-TATgPlzflu/lu and BALB/c.CD1d−/− mice as well as in an IL-4-deficient background, such as in CIITATgIL-4−/− and BALB/ c.IL-4−/− mice, indicating that the acquisition of an activated/memory-like phenotype was dependent on PLZF+ innate T cells and IL-4. Using fetal thymic organ culture, we further demonstrated that IL-4 in concert with TGF- enhanced the acquisition of the activated/memory-like phenotype of regulatory T cells. In functional aspects, the activated/memory-like phenotype of Treg cells was directly related to their suppressive function; regulatory T cells of CIITATgPIV-/- mice more efficiently suppressed ovalbumin-induced allergic airway inflammation compared with their counterparts from wild-type mice. All of these findings suggest that PLZF+ innate T cells also augmented the generation of activated/memory-like regulation via IL-4 production.

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>

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.