• 제목/요약/키워드: Major histocompatibility complex

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Relationship between Poor Immunogenicity of HLA-A2-Restricted Peptide Epitopes and Paucity of Naïve $CD8^+$ T-Cell Precursors in HLA-A2-Transgenic Mice

  • Choi, Yoon Seok;Lee, Dong Ho;Shin, Eui-Cheol
    • IMMUNE NETWORK
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    • 제14권4호
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    • pp.219-225
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    • 2014
  • We examined the immunogenicity of H-2 class I-restricted and HLA-A2-restricted epitopes through peptide immunization of HLA-A2-transgenic mice that also express mouse H-2 class I molecules. All four of the tested epitopes restricted by H-2 class I robustly elicited T-cell responses, but four of seven epitopes restricted by HLA-A2 did not induce T-cell responses, showing that HLA-A2-restricted peptide epitopes tend to be poorly immunogenic in HLA-A2-transgenic mice. This finding was confirmed in HLA-A2-transgenic mice infected with a recombinant vaccinia virus expressing hepatitis C virus proteins. We examined the precursor frequency of epitope-specific naïve $CD8^+$ T cells in HLA-A2-transgenic and conventional C57BL/6 mice and found that the poor immunogenicity of HLA-A2-restricted peptide epitopes is related to the paucity of naïve $CD8^+$ T-cell precursors in HLA-A2-transgenic mice. These results provide direction for the improvement of mouse models to study epitope repertoires and the immunodominance of human T-cell responses.

Polymerase Chain Reaction-Sequence Specific Primer를 이용한 HLA-A 유전자의 DNA 다형성 조사 (Genotyping of HLA-A by Polymerase Chain Reaction-Sequence Specific Primer)

  • 장순모
    • 대한임상검사과학회지
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    • 제40권2호
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    • pp.94-97
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    • 2008
  • The human leukocyte antigen (HLA) is the name of the major histocompatibility complex (MCH) in humans. The superlocus contains a large number of genes related to immune system function in humans. This group of genes resides on chromosome 6. and encode cell surface antigen-presenting proteins and many other genes. HLA class I antigen (A, B & C) present peptides from inside the cell. These peptides are produced from digested proteins that are broken down in the lysozymes. Most expressed HLA loci exhibit a remarkable degree of allelic polymorphism, which derives from sequence differences predominantly localized to discrete hypervariable regions of the amino terminal domain of the molecule. In this sutdy, the HLA-A genotypes were determined in twenty students unrelated koreans using the PCR-SSP (Polymerase Chain Reaction-Sequence Specific Primer) technique. Several specific primer pairs in assigning the HLA-A gene were used (A*0201, A*33, A*2401). The results of PCR-SSP, the HLA-A*0201 primer was detected eleven (55%), the HLA-A*33 were detected seven (35%) and the HLA-A*2401 were detected seven (35%). This study shows that the PCR-SSP technique is relatively simple, fast and a practical tool for the determination of the HLA-A genotypes.

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백혈구 표면항원 특이 단크론항체를 이용한 한우의 말초혈액 백혈구 아군에 관한 연구 (Subpopulation in periopheral blood leukocyte of Korean native cattle by using monoclonal antibodies specific to bovine leukocyte differentiation antigen)

  • 문진산;박용호;정석찬;구복경;강병규
    • 대한수의학회지
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    • 제36권2호
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    • pp.337-348
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    • 1996
  • The proportion of leukocyte subpopulation in the host is of a great importance in understanding their functions and disease progress. Many methods have been developed to seperate leukocytes and to measure their activities. Characterization of immune cell subpopulations in Korean native cattle was performed using a set of monoclonal antibodies specific which are specific to bovine leukocyte differentiation antigen. Peripheral blood leukocytes from fifty Korean native and ten Holstein cattle were collected and analyzed for the investigation of leukocyte subpopulation by using monoclonal antibodies and flow cytometry. The result indicated that Korean native cattle have significantly higher proportion of leukocyte subpopulations expressing MHC class II molecules and BoCD4 than Holstein cattle.

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Construction, and In Vitro and In Vivo Analyses of Tetravalent Immunoadhesins

  • Cho, Hoonsik;Chung, Yong-Hoon
    • 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.

Development of Natural Killer Cells from Hematopoietic Stem Cells

  • Yoon, Suk Ran;Chung, Jin Woong;Choi, Inpyo
    • Molecules and Cells
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    • 제24권1호
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    • pp.1-8
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    • 2007
  • Natural killer (NK) cells play a crucial role in innate immune system and tumor surveillance. NK cells are derived from $CD34^+$hematopoietic stem cells and undergo differentiation via precursor NK cells in bone marrow (BM) through sequential acquisition of functional surface receptors. During differentiation of NK cells, many factors are involved including cytokines, membrane factors and transcription factors as well as microenvironment of BM. NK cells express their own repertoire of receptors including activating and inhibitory receptors that bind to major histocompatibility complex (MHC) class I or class I-related molecules. The balance between activating and inhibitory receptors determines the function of NK cells to kill targets. Binding of NK cell inhibitory receptors to their MHC class I-ligand renders the target cells to be protected from NK cell-mediated cytotoxicity. Thus, NK cells are able to discriminate self from non-self through MHC class I-binding inhibitory receptor. Using intrinsic properties of NK cells, NK cells are emerging to apply as therapeutic agents against many types of cancers. Recently, NK cell alloactivity has also been exploited in killer cell immunoglobulin-like receptor mismatched haploidentical stem cell transplantation to reduce the rate of relapse and graft versus host disease. In this review, we discuss the basic mechanisms of NK cell differentiation, diversity of NK cell receptors, and clinical applications of NK cells for anti-cancer immunotherapy.

한우의 주요 조직 적합성 항원 규명 (Characterization of major histocompatibility complex antigen on Korean native cattles)

  • 윤석주;권명상
    • 대한수의학회지
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    • 제35권2호
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    • pp.307-315
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    • 1995
  • The characterization of the MHC of domestic animals may constitute a first step towards increasing the efficiency of food production through improved disease resistance. In order to study the role of the MHC in regulating immune response it is first necessary to identify the different MHC alleles. In this research we try to investigate the possible associations between BoLA of Korean native cattles and infectious cattle disease. For this purpose we used one approach, serology. The results were summarized as follows : 1. Korean native cattle's lymphocyte reacted with alloantisera which recognized seven official BoLA allele. Korean native cattle's lymphocytes were reacted same as European breeds(especially with 673/3(W20)). 2. Korean native cattle's lymphocytes reacted with alloantisera 773/2, 673/3, 638/3, 773/3, 602/2, 639/2 and 639/3 at high reaction frequency. But alloantisera 642/1 was not expressed on Korean native cattle. If this allele, recognized by alloantisera(642/1), officially certificate In BoLA workshop it will be characterization factor of Korean native cattle. 3. According to cellular similarity index, we can presume on genetic relativity which has no family relationship.

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Diversity of Chinese Indigenous Goat Breeds: A Conservation Perspective - A Review -

  • Li, M.H.;Li, K.;Zhao, S.H.
    • Asian-Australasian Journal of Animal Sciences
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    • 제17권5호
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    • pp.726-732
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    • 2004
  • In this manuscript, a review of the diversity of Chinese indigenous goat breeds according to data from body stature and appearance, chromosome group, blood proteins, DNA molecular markers (mitochondria DNA, random amplified polymorphic DNA, microsatellite DNA, major histocompatibility complex) has been introduced. All of these provide efficient tools for the diversity analysis of Chinese indigenous goat breeds and are very important for biodiversity conservation, restoration of declining goat breeds, the priority defining in Chinese indigenous goat breeds' protection and the selection of nature preservation zones. Many Chinese indigenous goat breeds with small population size in the isolated mountains or reservoir areas are verging the potential threat of extinction, effectively lost with the rapid destroying of ecological environment. On the other hand, as a result of the introduction of modern commercial goat breeds and shortage of effective conservation, some populations, such as Small-xiang goat and Tibetan goat decrease rapidly in number of sires. In the interests of the long-term future of the goat breeds in China, conservation of goat breeds' genetic resources should be considered urgently and some conservation measures should be adopted. In addition, the continuing development of molecular biology will further enhance conservation of diversity of Chinese indigenous goat breeds.

CD4O Activation Protects Dendritic Cells from Anticancer Drug-Induced Apoptosis

  • Jun, Jae-Yeon;Joo, Hong-Gu
    • The Korean Journal of Physiology and Pharmacology
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    • 제7권5호
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    • pp.255-259
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    • 2003
  • Dendritic cells (DCs) play a critical role in various immune responses involving $CD4^+$ T cells and have been used to generate anti-tumor immunity. Chemotherapy induces severe side effects including immunosuppression in patients with cancer. Although immunosuppression has been studied, the effects of anticancer drugs on DCs are not fully determined. In this study, we demonstrated that CD40 activation strongly protected DCs from 5-fluorouracil (5-FU) or mitomycin C-induced apoptosis. DCspecific surface markers, including CD11c and major histocompatibility complex (MHC) class II, were used for identifying DCs. CD 40 activation with anti-CD40 mAb significantly enhanced the viability of DCs treated with 5-FU or mitomycin C, assayed by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide). Fluorescence staining and analysis clearly confirmed the enhancing effect of anti-CD40 mAb on the viability of DCs, suggesting that CD40 activation may transduce critical signals for the viability of DCs. Annexin V staining assay showed that CD40 significantly protected DCs from 5-FU or mitomycin C-induced apoptosis. Taken together, this study shows that CD40 activation with anti-CD40 mAb has strong anti-apoptosis effect on DCs, suggesting that CD40 activation may overcome the immunosuppression, especially downregulation of number and function of DCs in chemotherapy-treated cancer patients.

HLA and Disease Associations in Koreans

  • Ahn, Stephen;Choi, Hee-Back;Kim, Tai-Gyu
    • IMMUNE NETWORK
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    • 제11권6호
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    • pp.324-335
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    • 2011
  • The human leukocyte antigen (HLA), the major histocompatibility complex (MHC) in humans has been known to reside on chromosome 6 and encodes cell-surface antigen-presenting proteins and many other proteins related to immune system function. The HLA is highly polymorphic and the most genetically variable coding loci in humans. In addition to a critical role in transplantation medicine, HLA and disease associations have been widely studied across the populations worldwide and are found to be important in prediction of disease susceptibility, resistance and of evolutionary maintenance of genetic diversity. Because recently developed molecular based HLA typing has several advantages like improved specimen stability and increased resolution of HLA types, the association between HLA alleles and a given disease could be more accurately quantified. Here, in this review, we have collected HLA association data on some autoimmune diseases, infectious diseases, cancers, drug responsiveness and other diseases with unknown etiology in Koreans and attempt to summarize some remarkable HLA alleles related with specific diseases.

T Lymphocyte Development and Activation in Humanized Mouse Model

  • Lee, Ji Yoon;Han, A-Reum;Lee, Dong Ryul
    • 한국발생생물학회지:발생과생식
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    • 제23권2호
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    • pp.79-92
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    • 2019
  • Humanized mice, containing engrafted human cells and tissues, are emerging as an important in vivo platform for studying human diseases. Since the development of Nod scid gamma (NSG) mice bearing mutations in the IL-2 receptor gamma chain, many investigators have used NSG mice engrafted with human hematopoietic stem cells (HSCs) to generate functional human immune systems in vivo, results in high efficacy of human cell engraftment. The development of NSG mice has allowed significant advances to be made in studies on several human diseases, including cancer and graft-versus-host-disease (GVHD), and in regenerative medicine. Based on the human HSC transplantation, organ transplantation including thymus and liver in the renal capsule has been performed. Also, immune reconstruction of cells, of the lymphoid as well as myeloid lineages, has been partly accomplished. However, crosstalk between pluripotent stem cell derived therapeutic cells with human leukocyte antigen (HLA) mis/matched types and immune CD3 T cells have not been fully addressed. To overcome this hurdle, human major histocompatibility complex (MHC) molecules, not mouse MHC molecules, are required to generate functional T cells in a humanized mouse model. Here, we briefly summarize characteristics of the humanized mouse model, focusing on development of CD3 T cells with MHC molecules. We also highlight the necessity of the humanized mouse model for the treatment of various human diseases.