• Journal of Microbiology and Biotechnology
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• 제22권8호
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• pp.1066-1076
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• 2012

Previous observations demonstrated that various immunosuppressive agents and their combination therapies can increase allograft survival rates. However, these treatments may have serious side effects and cannot substantially improve or prolong graft survival in acute graft-versus-host disease (GVHD). To improve the therapeutic potency of divalent immunoadhesins, we have constructed and produced several tetravalent forms of immunoadhesins comprising each of cytotoxic T-lymphocyte-associated antigen-4 (CTLA4), CD2, and lymphocyte activation gene-3 (LAG3). Flow cytometric and T cell proliferation analyses displayed that tetravalent immunoadhesins have a higher binding affinity and more potent efficacy than divalent immunoadhesins. Although all tetravalent immunoadhesins possess better efficacies, tetravalent forms of CTLA4-Ig and LAG3-Ig revealed higher inhibitory effects on T cell proliferation than tetravalent forms of TNFR2-Ig and CD2-Ig. In vitro mixed lymphocytes reaction (MLR) showed that combined treatment with tetravalent CTLA4-Ig and tetravalent LAG3-Ig was highly effective for inhibiting T cell proliferation in both human and murine allogeneic stimulation. In addition, both single tetravalent-form and combination treatments can prevent the lethality of murine acute GVHD. The results of this study demonstrated that co-blockade of the major histocompatibility complex class (MHC)II:T cell receptor (TCR) and CD28:B7 pathways by using tetravalent human LAG3-Ig and CTLA4-Ig synergistically prevented murine acute GVHD.

• 미생물학회지
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• 제49권3호
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• pp.221-227
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• 2013

인간면역결핍바이러스(Human immunodeficiency virus; HIV), B형 간염 바이러스(Hepatitis B virus; HBV), 그리고 C형 간염 바이러스(Hepatitis C virus; HCV)는 만성 감염질환을 일으키는 대표적인 바이러스들이다. 인체내 감염시 임상적 진행경과에 따른 바이러스 특이 T림프구의 항바이러스 기능변화 및 바이러스의 체내 지속성과 T림프구에 발현되는 다양한 면역인자(e.g., CD28, CD25, FoxP3, PD-1, CTLA-4)들과의 구체적인 상관관계는 최근 많은 국내외 연구진들을 통해 연구되고 있다. 그 중 FoxP3 (forkhead box P3), PD-1 (programmed death-1) 그리고 CTLA-4 (cytotoxic T lymphocyte-associated antigen 4)는 T림프구에서 발현되는 면역조절인자로 만성 바이러스성 감염시 그 발현이 증가되는 것으로 관찰되었으며, 항바이러스 작용을 가지는 T림프구의 기능결핍과 밀접한 상관관계가 있는 것으로 알려져 있다. 본 총설에서는 만성적인 HIV, HBV, 그리고 HCV 감염에서 바이러스 특이 T림프구에서 발현되는 FoxP3, PD1, 그리고 CTLA-4의 발현변화와 각 질환의 임상적 진행경과와의 상관성, 그리고 이들 발현이 T림프구의 항바이러스 기능에 미치는 영향 등을 중심으로 기술하였다.

• Clinical and Experimental Pediatrics
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• 제49권5호
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• pp.545-551
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• 2006

목 적 : Cytotoxic T lymphocyte-associated antigen-4(CTLA-4)를 표현하는 유전자는 IgE 조절과 T 세포의 활성에 중요한 역할을 하는 후보유전자로 알려져 있다. 본 연구에서는 CTLA-4 exon 1(＋49 position)과 promoter 유전자(-318 position)의 다형성과 한국 소아의 아토피피부염의 유전적 감수성 및 아토피피부염의 임상양상의 관계에 대해 알아보고자 하였다. 방 법 : 아토피성 습진 145명, 비아토피성 습진 69명과 대조군 96명을 대상으로 restriction fragment length polymorphism방법으로 CTLA-4 promoter(-318 T/C)와 exon 1(＋49 A/G)의 다형성을 조사하였다. 결 과 : CTLA-4 exon 1과 promoter의 유전자 다형성이 아토피성 습진 환아군이나 비아토피성 습진 환아군에서 대조군에 비해 의의있는 분포의 차이를 보이지 않았으며, 아토피피부염의 중증도, IgE 농도, 호산구의 수와도 유의한 관계가 없없다. 결 론 : 본 연구에서는 CTLA-4 유전자 다형성이 한국 소아의 아토피피부염의 유전적 감수성 및 아토피피부염의 임상양상에 관여하지 않는 것으로 생각된다.

• IMMUNE NETWORK
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• 제2권1호
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• pp.35-40
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• 2002

Background: CTLA-4 (Cytotoxic T Lymphocyte associated Antigen 4, CD152) has been known as a homologue of CD28, an accessory molecule providing a key costimulatory signal for successful antigen-driven activations of T lymphocyte. Most of biochemical and cell biological characteristics of the CD152 protein remain unknown while those of CD28 have been characterized in detail. Methods: In this study CD152 expression in both $CD4^+$ and $CD8^+$ PBLs was studied by using flow cytometry. And intracellular CD152 multiprotein complex was purified and used for generating antibodies recognizing proteins composing of intracellular CTLA-4 multi protein complex. Results: Level of surface expression of this molecule was peaked at 2 days of PHA stimulation in flow cytometric analysis. 40~45% of PHA blast cells were $CD152^+$ in both of two subsets at this stage and the level of expression were equivalent in both two subsets. Contrary to this surface expression, intracellular expression was peaked at day 3 and it was preferentially induced in $CD8^+$ cells and about 60% of $CD8^+$ cells were $CD152^+$ at this stage. High molecular weight (>350 kD) intacellular CD152 protein complex purified by using preparative electrophoresis were immunized into rabbits and then 3 different anti-P34PC4, anti-P34PC7 and anti-P34PC8 antibodies were obtained. Using these 3 antibodies two unknown antigens associated with intracellular CD152 multiprotein complex were found and their molecular weights were 54 kD and 75 kD, respectively. Among these, the former was present as 110 kD homodimer in non-reducing condition. Conclusion: It seemed that 34 kD intracellular CD152 molecule forms high molecular weight multiprotein complex at least with 2 proteins of 75 kD monomer and 110 kD homodimer.

• Asian Pacific Journal of Cancer Prevention
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• 제17권8호
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• pp.3785-3791
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• 2016

Background: Previous studies have assessed the association between the Cytotoxic T-lymphocyte Antigen-4(CTLA-4) polymorphism with the risk of malignant bone tumor, but the conclusions were inconsistent. We aimed to clarify association of cytotoxic T-lymphocyte antigen-4 polymorphisms with malignant bone tumors risk by performing a meta-analysis. Materials and Methods: The databases including PubMed, EMBase databases and the Cochrane Library were searched to identify the eligible studies prior to January 30 2016. Odds ratio (OR) with 95% confidence interval (95%CI) were used to estimate the strengths of the association between the CTLA-4 polymorphism and the malignant bone tumor risks. The meta-analysis was performed by STATA 12.0. Results: Four individual studies with a total of 1003 cases with malignant bone tumor and 1162 controls were included in our meta-analysis. The results of meta-analysis on those data demonstrated that CTLA-4 +49G>A polymorphism was associated with the risk of Ewing's sarcoma and osteosarcoma strongly (A vs. G: OR=1.36, 95%CI:1.20-1.54, p=0.000; AA+AG vs. GG: OR=1.35, 95%CI:1.14-1.61, p=0.001; AA vs. GG: OR=2.24, 95%CI:1.67-2.99, p=0.000; AA vs. AG+GG: OR=2.00, 95%CI:1.53-2.62, p=0.000), but CTLA-4 -318C/T polymorphism was not associated with the risk of malignant bone tumor (C vs. T: OR=0.76, 95%CI:0.76-1.08, p= 0.262; CC+CT vs. TT: OR=0.70, 95%CI:0.41-1.20, p= 0.198; CC vs. TT: OR=0.69, 95%CI:0.40-1.19, p= 0.183; CC vs. CT+TT: OR=0.92, 95%CI:0.75-1.13, p= 0.419). Subgroup analysis showed that there are significantly positive correlations between CTLA-4 +49G>A polymorphism and increased risks of malignant bone tumors in large size of sample (A vs. G: OR=1.347, 95%CI: 1.172,1.548, p=0.000; AA vs. GG: OR=2.228, 95%CI: 1.608,3.085, p=0.000), Ewing's Sarcoma or Osteosarcoma (A vs. G: OR=1.361, 95%CI: 1.201,1.540, p=0.000; AA vs. GG: OR=2.236, 95%CI: 1.674,2.986, p=0.000), and PCR-RFLP or Sequencing(A vs. G: OR=1.361, 95%CI: 1.201,1.540, p=0.000; AA vs. GG: OR=2.236, 95%CI: 1.674,2.986, p=0.000), but CTLA-4 -318C/T polymorphism was not associated with the risk of malignant bone tumors in diagnosis, genotype method, and sample size (all p>0.05). Conclusions: CTLA-4 +49A/G variant was associated with an increased risk of developing the malignant bone tumors, such as Ewing's sarcoma and osteosarcoma. However, it failed to show the association between CTLA-4 -318C/T polymorphism and the risk of malignant bone tumors. Future large-scale studies remain to be done to confirm our conclusions.

• IMMUNE NETWORK
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• 제10권4호
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• pp.120-125
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• 2010

Dysfunction of the virus-specific T cells is a cardinal feature in chronic persistent viral infections such as one caused by hepatitis C virus (HCV). In chronic HCV infection, virus-specific dysfunctional CD8 T cells often overexpress various inhibitory receptors. Programmed cell death 1 (PD-1) was the first among these inhibitory receptors that were identified to be overexpressed in functionally impaired T cells. The roles of other inhibitory receptors such as cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) and T cell immunoglobulin and mucin domain-containing molecule 3 (Tim-3) have also been demonstrated in T-cell dysfunctions that occur in chronic HCV patients. Blocking these inhibitory receptors in vitro restores the functions of HCV-specific CD8 T cells and allows enhanced proliferation, cytolytic activity and cytokine production. Therefore, the blockade of the inhibitory receptors is considered as a novel strategy for the treatment of chronic HCV infection.

• Asian Pacific Journal of Cancer Prevention
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• 제15권5호
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• pp.2035-2038
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• 2014

Cytotoxic T-lymphocyte antigen 4 (CTLA-4) is an important protein involved in the regulation of the immune system. The +49 G/A polymorphism is the only genetic variation in the CTLA-4 gene that causes an amino acid change in the resulting protein. It is therefore the most extensively studied polymorphism among all CTLA-4 genetic variants and contributions to increasing the likelihood of developing cancer are well known in various populations, especially Asians. However, there have hiterto been no data with respect to the effect of this polymorphism on breast cancer susceptibility in our North Indian population. We therefore assayed genomic DNA of 250 breast cancer subjects and an equal number of age-, sex- and ethnicity-matched healthy controls for the CTLA-4 +49 G/A polymorphism but no significant differences in either the gene or allele frequency were found. Thus the CTLA-4 +49 G/A polymorphism may be associated with breast cancer in other Asians, but it appears to have no such effect in North Indians. The study also highlights the importance of conducting genetic association studies in different ethnic populations.

• 한국임상약학회지
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• 제28권1호
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• pp.65-75
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• 2018

Objective: Over the last several years, immunotherapy has become one of the most promising therapeutic options for cancer. This study aims to summarize the updates on cancer immunotherapy focusing on immune checkpoint inhibitors, such as programmed cell death-1 (PD-1), programmed death-ligand 1 (PD-L1), and cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) inhibitors, which have received attention as new anticancer therapeutic agents. Methods: A literature survey was carried out on PubMed to identify high-impact papers on cancer immunotherapy from 2010. The most recent data on clinical efficacy and safety have been included highlighting the response characteristics to recently approved immunotherapeutic agents. Results: In various cancers, immune checkpoints are a means for cancer cells to evade the immune system. Furthermore, CTLA-4 and PD-L1 can be overexpressed, allowing malignant cells to evade T-cells. Numerous clinical trials have been performed to seek appropriate indication of these products in various cancer types. Among them, the most conspicuous types are melanoma, non-small-cell lung cancer, and head and neck cancer. The approval of ipilimumab by Food and Drug Administration (FDA) commenced a new era of cancer immunotherapy. This was followed by the approval of nivolumab and pembrolizumab. Currently, combination therapies are being investigated for various cancer types. Conclusion: In this study, we reviewed recently reported scientific and clinical evidence for currently approved immune checkpoint inhibitors. Although these novel checkpoint inhibitors are ever evolving for cancer therapies, there exist limitations that need to be overcome, indicating the necessity for further studies aiming to improve their efficacy, toxicity, and cost.

• 미생물학회지
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• 제47권4호
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• pp.342-347
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• 2011

인체의 바이러스 감염 방어기전에서 T 림프구는 중요한 역할을 한다. 하지만, 만성 C형 간염 바이러스의 일차적 복제장소인 간염 환자의 간에서 분리된 HCV 특이 T 림프구는 심각한 기능결핍을 보인다. 이러한 T 림프구 기능결핍의 이유로는 PD-1, CTLA-4 등 면역억제 물질의 발현, 또는 간에서 특이적으로 유도되는 면역내성(immune tolerance)이 있으나, 간세포(hepatocytes)와 HCV 특이 T 림프구의 상호작용에 대해서는 명확하게 확립되어 있지 않다. 따라서 본 연구에서는 HLA(human leukocyte antigen) A2+ 간암세포주(human hepatoma cell line; huh7.5)가 항원제시(antigen presentation)를 통해 효과적으로 HCV 특이 T 림프구를 활성화시키며 간암세포주(huh7.5) 표면의 PD-L (program death ligand) 1 발현은 T림프구의 활성을 감소시켜 면역조절의 가능성이 있음을 시사하였다. 또한, HCV 특이 tetramer 반응은 T 림프구의 과도한 활성으로 자기사멸(apoptosis)의 경로에 있음을 caspase 3 활성으로 확인하였고, 역시 PD-L1의 발현이 T 림프구를 자기사멸(apoptosis)로부터 구제하여 caspase 3 활성이 감소하는 것을 확인하였다. 이는 PD-L1과 간성(liver) T 림프구 표면의 PD-1 결합이 T 림프구의 자기사멸을 막고, 또한 그 기능을 회복시켜 만성 C형 간염 치료에 응용될 수 있음을 시사한다.

• Pediatric Infection and Vaccine
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• 제30권3호
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• pp.129-138
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• 2023

목적: 선천면역장애 환자들은 감염에 취약할 뿐만 아니라, 면역이 정상인 사람들에 비해 암 발생률도 높은 것으로 알려져 있다. 본 연구는 단일 기관에서 추적 중인 선천면역장애 환자들에서의 암 발생을 조사하여 보고자 하였다. 방법: 1994년 11월부터 2023년 9월까지 삼성서울병원에서 선천면역장애 진단 하에 추적하는 환자를 대상으로 후향적으로 의무기록을 리뷰하였다. 선천면역장애 환자 중에서 암으로 진단된 환자를 확인하였다. 결과: 총 194명의 선천면역장애 환자 중, 7명(3.6%)의 환자에서 암이 진단되었다. 5명의 환자가 림프종으로 진단받았으며 그 중 4명의 환자는 Epstein-Barr 바이러스 연관 림프종이었다. 나머지 암은 위암과 다발 골수종이었다. 암 진단 당시 나이는 중앙값 18세 (범위, 1세–75세)였다. 암이 발생한 환자들의 면역결핍 질환은 X-linked lymphoproliferative disorder-1 (XLP-1) 3명, activated phosphoinositide 3-kinase delta disease (APDS) 2명, cytotoxic T-lymphocyte antigen 4 (CTLA-4) haplo-insufficiency 2명이었다. 개별 질환별로 분석하였을 때, XLP-1 환자의 75.0%, APDS 환자의 40.0%, CTLA-4 환자의 50.0%에서 암이 발생하였다. XLP-1 환자는 APDS 및 CTLA-4 haplo-insufficiency 환자에 비해 더 이른 나이에 암이 발생하였다 (중앙연령 5세, P<0.001). 한 명은 조혈모세포 이식 치료 중 사망하였다. 결론: 국내 단일 기관에서 진료받는 선천면역장애 환자들의 3.6%에서 암이 발생하였다. 선천면역장애 환자들을 진료하는 의료진들은 이들 환자에서 감염이나 염증 등의 문제외에도 암 발생의 가능성, 특히 Epstein-Barr 바이러스 감염과 연관된 암의 비중이 높은 것에 대한 인식을 갖는 것이 중요하다.