• Molecules and Cells
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• 제42권11호
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• pp.747-754
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• 2019

The incidence of atherosclerosis is higher among patients with several autoimmune diseases such as psoriasis, rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). It is well documented that innate immune cells including macrophages and dendritic cells sense lipid species such as saturated fatty acids and oxidized low-density lipoprotein and produce pro-inflammatory cytokines and chemokines. However, whether a hyperlipidemic environment also impacts autoimmune T cell responses has been unclear. Among $CD4^+$ T cells, Th17 and follicular helper T (Tfh) cells are known to play pathogenic roles in the development of hyperlipidemia-associated autoimmune diseases. This review gives an overview of the cellular and molecular mechanisms by which dysregulated lipid metabolism impacts the pathogenesis of autoimmune diseases, with specific emphasis on Th17 and Tfh cells.

• 대한피부과학회지
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• 제56권10호
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• pp.620-623
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• 2018

Vitiligo is a multifactorial disorder. Neural, biochemical, and autoimmune mechanisms have been hypothetically suggested as etiopathological contributors to this condition. Autoimmunity focuses primarily on genetic factors and the association between vitiligo and other autoimmune disorders including autoimmune thyroid disease, rheumatoid arthritis, psoriasis, type 1 diabetes, pernicious anemia, and Addison's disease. We describe a 35-year-old man with systemic lupus erythematosus who developed concurrent vitiligo and discoid lupus erythematosus suggesting the possible autoimmune association between these 2 different diseases.

• Childhood Kidney Diseases
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• 제27권1호
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• pp.1-10
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• 2023

Pediatric nephrotic syndrome (NS) is a clinical syndrome characterized by massive proteinuria, hypoalbuminemia, and generalized edema. Most childhood NS cases are idiopathic (with an unknown etiology). Traditional therapeutic approaches based on immunosuppressive agents largely support the key role of the immune system in idiopathic NS (INS), especially in the steroid-sensitive form. Although most previous studies have suggested the main role of T cell dysfunction and/or the abnormal secretion of certain glomerular permeability factors, recent studies have emphasized the role of B cells since the therapeutic efficacy of B cell depletion therapy in inducing and/or maintaining prolonged remission in patients with INS was confirmed. Furthermore, several studies have detected circulating autoantibodies that target podocyte proteins in a subset of patients with INS, suggesting an autoimmune-mediated etiology of INS. Accordingly, a new therapeutic modality using B cell-depleting drugs has been attempted, with significant effects in a subset of patients with INS. Currently, INS is considered an immune-mediated disorder caused by a complex interplay between T cells, B cells, soluble factors, and podocytes, which may vary among patients. More in-depth investigations of the pathogenic pathways of INS are required for an effective personalized therapeutic approach and to define precise targets for therapeutic intervention.

• IMMUNE NETWORK
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• 제24권1호
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• pp.2.1-2.24
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• 2024

Studies over the last 2 decades have identified IL-17 and IL-21 as key cytokines in the modulation of a wide range of immune responses. IL-17 serves as a critical defender against bacterial and fungal pathogens, while maintaining symbiotic relationships with commensal microbiota. However, alterations in its levels can lead to chronic inflammation and autoimmunity. IL-21, on the other hand, bridges the adaptive and innate immune responses, and its imbalance is implicated in autoimmune diseases and cancer, highlighting its important role in both health and disease. Delving into the intricacies of these cytokines not only opens new avenues for understanding the immune system, but also promises innovative advances in the development of therapeutic strategies for numerous diseases. In this review, we will discuss an updated view of the immunobiology and therapeutic potential of IL-17 and IL-21.

• IMMUNE NETWORK
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• 제16권5호
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• pp.271-280
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• 2016

Tertiary lymphoid structures (TLS) are ectopic lymphoid tissues involved in chronic inflammation, autoimmune diseases, transplant rejection and cancer. They exhibit almost all the characteristics of secondary lymphoid organs (SLO), which are associated with adaptive immune responses; as such, they contain organized B-cell follicles with germinal centers, distinct areas containing T cells and dendritic cells, high endothelial venules, and lymphatics. In this review, we briefly describe the formation of SLO, and describe the cellular subsets and molecular cues involved in the formation and maintenance of TLS. Finally, we discuss the associations of TLS with human diseases, especially autoimmune diseases, and the potential for therapeutic targeting.

• IMMUNE NETWORK
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• 제16권4호
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• pp.219-232
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• 2016

Production of high affinity antibodies for antigens is a critical component for the immune system to fight off infectious pathogens. However, it could be detrimental to our body when the antigens that B cells recognize are of self-origin. Follicular helper T, or Tfh, cells are required for the generation of germinal center reactions, where high affinity antibody-producing B cells and memory B cells predominantly develop. As such, Tfh cells are considered as targets to prevent B cells from producing high affinity antibodies against self-antigens, when high affinity autoantibodies are responsible for immunopathologies in autoimmune disorders. This review article provides an overview of current understanding of Tfh cells and discusses it in the context of animal models of autoimmune diseases and allograft rejections for generation of novel therapeutic interventions.

• Clinical and Experimental Pediatrics
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• 제48권6호
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• pp.624-633
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• 2005

목 적 : 본 연구는 한국인 제 1형 당뇨병 환자들에서 HLADR과 DQ 유전자형 및 갑상선 자가항체(항 TPO 자가항체와 항 thyroglobulin 자가항체)를 분석함으로써, 한국인 제 1형 당뇨병과 관련 있는 특정 HLA 유전자형을 알아보고자 하였고, 이들 제 1형 당뇨병 환자들에서의 갑상선 자가항체의 유병률, 갑상선 질환으로의 발현 및 이들 자가면역성 갑상선염과 HLA 유전자형과의 관련성을 알아보고자 하였다. 방 법 : 총 59명[남아 26명, 검사시 연령 13.7세(5.7-29.9세), 당뇨병 유병기간 7.6년(-1.7-22.5년)]의 제 1형 당뇨병 환자를 대상으로 하였고, 갑상선 질환의 병력 및 가족력이 없는 건강한 200명의 한국인의 HLA 유전자형을 대조군으로 하였다. 59명의 환자 중 갑상선 자가항체 양성인 17명은 중앙기간 3.96년(1일-10.7년) 동안 진찰 및 anti-TPO, anti-TG, $T_3$, $T_4$ 또는 free $T_4$, TSH 검사를 시행하면서 추적 관찰하였다. HLA-DR과 DQ의 유전자 분석은 PCR-SSO, PCR-SSCP, PCR-RFLP 및 PCR-SSP 방법을 이용하였다. 결 과 : 제 1형 당뇨병 환자들에서 대조군에서보다 HLADRB1*0301, *090102, DQB1*0201, *030302, DRB1*0301/*090102, DRB1*090102/*090102, DQB1*0201/*030302, *030302/*030302, *0201/*0302의 빈도가 높았다(Pc<0.05). 15명(25.4%)에서 TPO에 대한 자가항체 양성이었고, 12명(20.3%)에서 TG 자가항체 양성이었으며, 17명(28.8%)은 두 가지 항체 중 한 가지 이상의 항체를 갖고 있었다. 10명(16.9%)은 두 종류의 항체를 모두 갖고 있었다. 갑상선 항체 양성을 보인 이후부터의 추적기간 동안 갑상선기능저하증을 보인 경우는 없었다. 3명(5.1%)의 여아에서 당뇨병 진단 전 또는 후에 갑상선기능항진증이 진단(8.5세, 11세, 13.2세)되었다. 갑상선 자가항체의 유무 및 각각의 항체 종류에 따른 대상군간의 제 1형 당뇨병 진단연령, 갑상선 검사시 연령, 당뇨병 유병기간 및 성별의 차이는 보이지 않았다(P>0.05). 결 론 : 한국인에서는 HLA-DRB1*0301, *090102, DQB1*0201, *030302, DRB1*0301/*090102, *090102/*090102, DQB1*0201/*030302, *030302/*030302, *0201/*0302 등이 제 1형 당뇨병에 대한 감수성 인자였고, 코카시안과는 다른 HLA-DR 및 DQ의 분포가 한국인에서 제 1형 당뇨병의 발생률이 낮은 이유중의 하나를 차지하리라고 생각되었다. 한편, 제 1형 당뇨병 환자들에서 갑상선 자가항체 양성률은 28.8%였고, 이는 한국인 제 1형 당뇨병 환자에서도 갑상선 자가항체 검사가 규칙적으로 시행되어야 함을 시사한다고 하겠다. 한국인 제 1형 당뇨병 환자에서 자가면역성 갑상선 질환에 대한 선별검사 시작 시기와 횟수 등에 대해서는 이들 환자들의 장기적인 추적관찰을 통해 추후 좀더 연구가 필요하리라 생각된다.

• IMMUNE NETWORK
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• 제14권1호
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• pp.21-29
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• 2014

Follicular helper T ($T_{FH}$) cells are recently highlighted as their crucial role for humoral immunity to infection as well as their abnormal control to induce autoimmune disease. During an infection, na$\ddot{i}$ve T cells are differentiating into $T_{FH}$ cells which mediate memory B cells and long-lived plasma cells in germinal center (GC). $T_{FH}$ cells are characterized by their expression of master regulator, Bcl-6, and chemokine receptor, CXCR5, which are essential for the migration of T cells into the B cell follicle. Within the follicle, crosstalk occurs between B cells and $T_{FH}$ cells, leading to class switch recombination and affinity maturation. Various signaling molecules, including cytokines, surface molecules, and transcription factors are involved in $T_{FH}$ cell differentiation. IL-6 and IL-21 cytokine-mediated STAT signaling pathways, including STAT1 and STAT3, are crucial for inducing Bcl-6 expression and $T_{FH}$ cell differentiation. $T_{FH}$ cells express important surface molecules such as ICOS, PD-1, IL-21, BTLA, SAP and CD40L for mediating the interaction between T and B cells. Recently, two types of microRNA (miRNA) were found to be involved in the regulation of $T_{FH}$ cells. The miR-17-92 cluster induces Bcl-6 and $T_{FH}$ cell differentiation, whereas miR-10a negatively regulates Bcl-6 expression in T cells. In addition, follicular regulatory T ($T_{FR}$) cells are studied as thymus-derived $CXCR5^+PD-1^+Foxp3^+\;T_{reg}$ cells that play a significant role in limiting the GC response. Regulation of $T_{FH}$ cell differentiation and the GC reaction via miRNA and $T_{FR}$ cells could be important regulatory mechanisms for maintaining immune tolerance and preventing autoimmune diseases such as systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). Here, we review recent studies on the various factors that affect $T_{FH}$ cell differentiation, and the role of $T_{FH}$ cells in autoimmune diseases.

• IMMUNE NETWORK
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• 제20권5호
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• pp.43.1-43.11
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• 2020

Capicua (CIC) is a transcriptional repressor that regulates several developmental processes. CIC deficiency results in lymphoproliferative autoimmunity accompanied by expansion of CD44^hiCD62L^lo effector/memory and follicular Th cell populations. Deletion of Cic alleles in hematopoietic stem cells (Vav1-Cre-mediated knockout of Cic) causes more severe autoimmunity than that caused by the knockout of Cic in CD4⁺CD8⁺ double positive thymocytes (Cd4-Cre-mediated knockout of Cic). In this study, we compared splenic CD4⁺ T cell activation and proliferation between whole immune cell-specific Cic-null (Cic^f/f;Vav1-Cre) and T cell-specific Cic-null (Cic^f/f;Cd4-Cre) mice. Hyperactivation and hyperproliferation of CD4⁺ T cells were more apparent in Cic^f/f;Vav1-Cre mice than in Cic^f/f;Cd4-Cre mice. Cic^f/f;Vav1-Cre CD4⁺ T cells more rapidly proliferated and secreted larger amounts of IL-2 upon TCR stimulation than did Cic^f/f;Cd4-Cre CD4⁺ T cells, while the TCR stimulation-induced activation of the TCR signaling cascade and calcium flux were comparable between them. Mixed wild-type and Cic^f/f;Vav1-Cre bone marrow chimeras also exhibited more apparent hyperactivation and hyperproliferation of Cic-deficient CD4⁺ T cells than did mixed wild-type and Cic^f/f;Cd4-Cre bone marrow chimeras. Taken together, our data demonstrate that CIC deficiency at the beginning of T cell development endows peripheral CD4⁺ T cells with enhanced T cell activation and proliferative capability.

• IMMUNE NETWORK
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• 제11권5호
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• pp.227-244
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• 2011

MicroRNAs (miRNAs) are small noncoding RNA molecules that negatively regulate gene expression via degradation or translational repression of their target messenger RNAs (mRNAs). Recent studies have clearly demonstrated that miRNAs play critical roles in several biologic processes, including cell cycle, differentiation, cell development, cell growth, and apoptosis and that miRNAs are highly expressed in regulatory T (Treg) cells and a wide range of miRNAs are involved in the regulation of immunity and in the prevention of autoimmunity. It has been increasingly reported that miRNAs are associated with various human diseases like autoimmune disease, skin disease, neurological disease and psychiatric disease. Recently, the identification of miRNAs in skin has added a new dimension in the regulatory network and attracted significant interest in this novel layer of gene regulation. Although miRNA research in the field of dermatology is still relatively new, miRNAs have been the subject of much dermatological interest in skin morphogenesis and in regulating angiogenesis. In addition, miRNAs are moving rapidly center stage as key regulators of neuronal development and function in addition to important contributions to neurodegenerative disorder. Moreover, there is now compelling evidence that dysregulation of miRNA networks is implicated in the development and onset of human neruodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, Huntington's disease, Tourette's syndrome, Down syndrome, depression and schizophrenia. In this review, I briefly summarize the current studies about the roles of miRNAs in various autoimmune diseases, skin diseases, psychoneurological disorders and mental stress.