• Title/Summary/Keyword: HLA-G1

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Immunoregulatory Function of HLA-G in Gastric Cancer

  • Tuncel, Tolga;Karagoz, Bulent;Haholu, Aptullah;Ozgun, Alpaslan;Emirzeoglu, Levent;Bilgi, Oguz;Kandemir, Emin Gokhan
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.12
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    • pp.7681-7684
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    • 2013
  • Background: Human leukocyte antigen (HLA)-G-positive gastric cancers are associated with poor survival, but links with tumor escape mechanisms remain to be determined. Materials and Methods: We used immunohistochemistry to investigate HLA-G expression, tumor infiltrating CD8+ T lymphocytes, and Treg cells in 52 gastric cancer patients. Results: There were 29 cancer-related deaths during the follow-up period. Kaplan-Meier analysis indicated that patients with HLA-G-positive (n=16) primary tumors had a significantly poorer prognosis than patients with HLA-G-negative tumors (n=36, p=0.008). The median survival time was 14 months and 47 months, respectively. Patients with high numbers of Tregs and low numbers of CD8+T lymphocytes in the primary tumor had a poorer prognosis than those with low numbers of Tregs and high numbers of CD8+T lymphocytes (p=0.034, p=0.043). Multivariate Cox proportional hazard regression analysis showed that HLA-G expression (hazard ratio: 2.662; 95% confidence interval: 1.242-5.723; p=0.012) and stage (hazard ratio: 2.012;95% confidence interval: 1.112-3.715; p=0.041) were independent unfavorable factors for patient survival. Conclusions: We found a significant positive correlation between HLA-G expression and the number of tumor infiltrating Tregs (p=0.01) and a negative correlation with the number of CD8+T lymphocytes (p=0.041). HLA-G may protect gastric cancer cells from cytolysis by inducing Foxp3+Treg lymphocytes and suppressing CD8+T lymphocytes.

Association of HLA-G gene promoter haplotype with childhood IgA nephropathy in the Korean population (한국인에서의 소아 IgA 신병증과 HLA-G유전자의 promoter haplotype과의 관계)

  • Jung, Hwan-Hee;Hahn, Won-Ho;Cho, Byoung-Soo;Kim, Sung-Do
    • Clinical and Experimental Pediatrics
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    • v.53 no.4
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    • pp.548-553
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    • 2010
  • Purpose : IgA nephropathy (IgAN) is the most commonly occurring form of chronic glomerulonephritis in pediatric cases. Human leukocyte antigen (HLA) genes have been implicated in various inflammatory and autoimmune diseases. The present study was conducted to investigate the association between 2 single nucleotide polymorphisms (SNPs) of the HLA-G gene and childhood IgAN. Methods : The authors analyzed and compared $HLA-G$ gene SNPs (rs1736936 and rs2735022) in 174 patients with childhood IgAN and in 438 healthy controls. In addition, IgAN patients were dichotomized and compared with respect to proteinuria (< and >$4mg/m^2/hour$), the presence or absence of podocyte foot process effacement, and the presence of pathologically early and advanced disease markers such as interstitial fibrosis, tubular atrophy, or global sclerosis. Results : No significant SNP frequency differences were observed for the $HLA-G$ gene between IgAN patients and the control group. Moreover, no significantly associated SNP was observed with the presence of proteinuria, podocyte foot process effacement, or pathologically advanced markers. However, the haplotype, composed of rs1736936 and rs2735022, showed a significant association with the susceptibility to develop childhood IgAN (haplotype T/C: dominant model, $P$=0.049; haplotype C/T: recessive model, $P$=0.030). Conclusion : Our results indicate that rs1736936 and rs2735022 as the $HLA-G$ gene promoter haplotype might be associated with the susceptibility to develop childhood IgAN in the Korean population.

The Association of HLA-DRB1 and DQB1 Alleles and a Study of Anticardiolipin Antibody and Anti-β2 Glycoprotein I Antibody in Korean SLE Patients (한국인 전신성홍반성루푸스 환자에서 HLA-DRB1, DQB1 대립유전자의 연관성 및 항인지질 항체와 항β2 Glycoprotein I 항체에 관한 연구)

  • Lee, Sang Gon;Cha, Hoon Suk;Yang, Yoon Sun
    • IMMUNE NETWORK
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    • v.2 no.4
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    • pp.227-232
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    • 2002
  • Background: Systemic lupus erythematosus (SLE) is a complex autoimmune disease characterized by diverse clinical manifestations and autoantibody production, which is known to be strongly influenced by genetic factors. Previous studies have revealed the associations of SLE with HLA class II alleles and antiphospholipid antibody system (anticardiolipin antibody (aCL) and anti-${\beta}_2$ glycoprotein I antibody (anti-${\beta}_2$ GPI)). Therefore, we studied the associations of HLA class II alleles with SLE and antiphospholipid antibody system. Methods: The genotyping for HLA-DRB1 and DQB1 alleles were performed in 61 SLE patients and 100 controls by the polymerase chain reaction (PCR)-sequence specific oligonucleotide probe method. ELISA tests for aCL and anti-${\beta}_2$ GPI were performed in 39 of the 61 SLE patients. The results were evaluated statistically by Chi-square test. Results: The frequencies of the HLA-$DRB1^*15$ and $DQB1^*06$ in SLE patients were significantly higher than those in controls. HLA-$DRB1^*12$ was significantly lower in SLE patients than controls. Nine of 39 patients were positive for aCL (IgG) and three were positive for aCL (IgM). One of 39 patients were positive for anti-${\beta}_2$ GPI (IgG) and none of them positive for anti-${\beta}_2$ GPI (IgM). Association of aCL with HLA class II alleles was not observed in our study. Conclusion: According to our results, it was found that HLA-$DRB1^*15$ and $DQB1^*06$ were associated with genetic susceptiblility and $DRB1^*12$ was associated with resistance to SLE in Korean population. No Association of aCL with HLA class II alleles was observed and the positive rate for anti-${\beta}_2$ GPI was very low.

HLA-Based Distributed Object-Oriented War Game Simulation on GRID (GRID를 이용한 HLA 기반 객체 지향 분산 시뮬레이션)

  • 김창훈;이태동;유양선;정창성;박형우
    • Proceedings of the Korean Information Science Society Conference
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    • 2002.10c
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    • pp.367-369
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    • 2002
  • 본 논문은 GRID 상에서 HLA(High Level Architecture)를 기반으로 한 분산 객체 지향 wargame simulation의 디자인과 구현에 관해 기술한다. HLA는 DIS[1]의 뒤를 이어 제안된 아키텍처로서 simulation에 원활한 data교류와 동기화를 제공한다. 또한, GRID는 전세계에 펼쳐져 있는 자원들에 대한 관리와 접근, 사용을 위한 다양한 기능과 안전하고 편리한 security를 보장한다. 본 논문에서는 HLA를 사용해서 simulation에 튀어난 상호 연동 능력과 재사용성을 부여하고, GRID를 통해 대규모의 프로젝트를 위한 광범위한 자원을 보다 안전하고 효율적으로 사용할 수 있도록 하는 환경을 구현하였다. 우리는 이 simulation을 HDOWS-G(HLA-based Distributed Object-oriented War game Simulation on Grid)라 부르기로 한다.

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Family Study of TAP Gene Polymorphism and HLA-TAP Haplotypes in Koreans (가계조사를 통한 한국인의 TAP 유전자의 다형성과 HLA-TAP 일배체형 분포에 관한 연구)

  • Whang, Dong Hee;Park, Myoung Hee
    • IMMUNE NETWORK
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    • v.2 no.4
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    • pp.248-255
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    • 2002
  • Background: TAP1 and TAP2 are two ABC transporter genes located within the class II region of the human MHC. Their protein products form a heterodimer whose function is to transport peptides from the cytoplasm into the endoplasmic reticulum. This study was performed to examine the polymorphism of TAP genes and the distribution of HLA-TAP haplotypes in the Korean population through family analysis. Methods: The subjects used in this study were 50 healthy Korean families consisting of 233 individuals. TAP1 (codons 333 and 637) and TAP2 (codons 379, 565, 577, 651, 665, and 687) typings were carried out by the PCR-restriction fragment length polymorphism (RFLP) method. HLA-DRB1 and DQB1 genotyping results from a previous study were used for HLA-TAP haplotype analysis. Results: The number (gene frequency) of TAP1 and TAP2 alleles detected were 3 for TAP1 (A 81.5%, B 17.0%, and C 1.5%) and 8 for TAP2 (A1 32.0%, A2 12.5%, B 34.0%, Bky2 6.5%, C 7.0%, D 3.0%, E 4.5%, and G 0.5%). Eleven TAP1-TAP2 haplotypes were observed with $frequency{\geq}1%$, among which 4 haplotypes (A-B, B-A1, A-Bky2, and C-E) showed weak but significant positive linkage disequilibrium (P<0.05). When DRB1-DQB1 haplotypes were extended to TAP1 and TAP2 loci, much diversification of haplotypes was observed: 19 different DRB1-DQB1 haplotypes formed 58 different haplotypes extended to TAP1 and TAP2 loci. These results add more evidence to the view that recombination hotspot is present within and around TAP gene region. Conclusion: The allele frequencies of TAP1 and TAP2 genes and the distribution of TAP1-TAP2 and HLA-TAP haplotypes were studied in Koreans based on a family study.

Immunologic Aspects at the Feto-Maternal Interface (태아모체간 계면에서의 면역학적 측면)

  • 정인배
    • Development and Reproduction
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    • v.5 no.2
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    • pp.93-100
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    • 2001
  • Precise mechanism by which the fetus can escape from mother's immune rejection is not well understood yet over the last 50 years. The clarification of immune mechanism at the feto-maternal interface is very important, because this can be a common pathogenesis of various pathologic conditions including spontaneous abortion, habitual abortion fetal growth restriction preeclampsia, implantation failure after assisted reproductive techniques, and fetal death. In this review, current hypothetical contents were described with the priority of importance: 1) The center of this mechanism is cross-talk between the expression of HLA-C, E, G on the extravillous cytotrophoblasts and their receptors on decidual NK cell, 2) immunomodulation, 3) innate immunity is the main immunologic mechanism, 4) various mechanisms besides HLA system(eq. complement) may be associated. The overall balance of immunomodulation among these mechanisms should result in the outcome of each pregnancy. Further researches regarding the regulation of HLA system, roles of cytokines, complements should be followed in the future.

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Polymorphisms in the TNF-α Gene and Extended HLA and TNF-α Haplotypes in Koreans (한국인에서의 TNF-α 유전자 다형성과 HLA/TNF-α 일배체형의 분포)

  • Park, Yoon June;Park, Hye Jin;Park, Myoung Hee
    • IMMUNE NETWORK
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    • v.2 no.4
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    • pp.242-247
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    • 2002
  • Background: Tumor necrosis factor-alpha (TNF-$\alpha$) is known to play an important role in various conditions such as inflammation, autoimmunity, apoptosis, insulin resistance and sleep induction. Five single nucleotide polymorphisms (SNPs) have been known to affect the transcriptional activities of TNF-$\alpha$: -1,031T/C, -863C/A, -857C/T, -308G/A and -238G/A. Methods: We have investigated 5 SNPs of the promoter region of TNF-$\alpha$ gene, the distribution of 5-locus TNF-$\alpha$ haplotypes, and their haplotypic associations with previously typed HLA-A, -B and -DRB1 loci in 107 healthy unrelated Koreans. TNF-$\alpha$ SNPs were typed using PCR-single-strand conformation polymorphism (SSCP) and PCR-restriction fragment length polymorphism (RFLP) methods. Results: The allele frequencies of -1,031C, -863A, -857T, -308A, and-238A, which are known as the high-producer-type, were 19.3%, 15.9%, 14.0%, 5.9%, and 2.9%, respectively. The frequency of -308A allele, known to be associated with autoimmune diseases, was 5.9% in Koreans which was lower than Caucasians (14~17%) and somewhat higher than Japanese (1.7%). Five most common TNF-$\alpha$ haplotypes (-1,031/-863/-857/-308/-238) comprised over 95% of total haplotypes: TCCGG (58.4%), CACGG (14.8%), TCTGG (13.7%), TCCAG (5.3%), and CCCGA (3.1%). Strong positive associations (P<0.001) were observed between TCCGG and B62; between CACGG and B51, $DRB1^*0901$; between TCTGG and B35, B54, B59, $DRB1^*1201$; and between TCCAG and A33, B58, $DRB1^*0301$, $DRB1^*1302$. Five most common extended haplotypes (>3%) comprised around 16% of total haplotypes: A33-B58-TCCAG-$DRB1^*1302$, A24-B52-TCCGG-$DRB1^*1502$, A33-B44-TCCGG-$DRB1^*1302$, A24-B7-TCCGG-$DRB1^*0101$, and A11-B62-TCCGG-$DRB1^*0406$. The distribution of extended HLA and TNF-$\alpha$ haplotypes showed that most of HLA haplotypes were almost exclusively associated with particular TNF-$\alpha$ haplotypes. Conclusion: The results obtained in this study would be useful as basic data for anthropologic studies and disease association studies in Koreans.

Structural and Mechanistic Insights into the Tropism of Epstein-Barr Virus

  • Mohl, Britta S.;Chen, Jia;Sathiyamoorthy, Karthik;Jardetzky, Theodore S.;Longnecker, Richard
    • Molecules and Cells
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    • v.39 no.4
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    • pp.286-291
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    • 2016
  • Epstein-Barr virus (EBV) is the prototypical ${\gamma}$-herpesvirus and an obligate human pathogen that infects mainly epithelial cells and B cells, which can result in malignancies. EBV infects these target cells by fusing with the viral and cellular lipid bilayer membranes using multiple viral factors and host receptor(s) thus exhibiting a unique complexity in its entry machinery. To enter epithelial cells, EBV requires minimally the conserved core fusion machinery comprised of the glycoproteins gH/gL acting as the receptor-binding complex and gB as the fusogen. EBV can enter B cells using gp42, which binds tightly to gH/gL and interacts with host HLA class II, activating fusion. Previously, we published the individual crystal structures of EBV entry factors, such as gH/gL and gp42, the EBV/host receptor complex, gp42/HLA-DR1, and the fusion protein EBV gB in a postfusion conformation, which allowed us to identify structural determinants and regions critical for receptor-binding and membrane fusion. Recently, we reported different low resolution models of the EBV B cell entry triggering complex (gHgL/gp42/HLA class II) in "open" and "closed" states based on negative-stain single particle electron microscopy, which provide further mechanistic insights. This review summarizes the current knowledge of these key players in EBV entry and how their structures impact receptor-binding and the triggering of gB-mediated fusion.