Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 305
Filtrar
Mais filtros










Filtros aplicados

Base de dados
Intervalo de ano de publicação
1.
Hum Mol Genet ; 27(24): 4333-4343, 2018 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-30215709

RESUMO

Birdshot Uveitis (Birdshot) is a rare eye condition that affects HLA-A29-positive individuals and could be considered a prototypic member of the recently proposed 'MHC-I (major histocompatibility complex class I)-opathy' family. Genetic studies have pinpointed the endoplasmic reticulum aminopeptidase (ERAP1) and (ERAP2) genes as shared associations across MHC-I-opathies, which suggests ERAP dysfunction may be a root cause for MHC-I-opathies. We mapped the ERAP1 and ERAP2 haplotypes in 84 Dutch cases and 890 controls. We identified association at variant rs10044354, which mediated a marked increase in ERAP2 expression. We also identified and cloned an independently associated ERAP1 haplotype (tagged by rs2287987) present in more than half of the cases; this ERAP1 haplotype is also the primary risk and protective haplotype for other MHC-I-opathies. We show that the risk ERAP1 haplotype conferred significantly altered expression of ERAP1 isoforms in transcriptomic data (n = 360), resulting in lowered protein expression and distinct enzymatic activity. Both the association for rs10044354 (meta-analysis: odds ratio (OR) [95% CI]=2.07[1.58-2.71], P = 1.24 × 10(-7)) and rs2287987 (OR[95% CI]: =2.01[1.51-2.67], P = 1.41 × 10(-6)) replicated and showed consistent direction of effect in an independent Spanish cohort of 46 cases and 2103 controls. In both cohorts, the combined rs2287987-rs10044354 haplotype associated with Birdshot more strongly than either variant alone [meta-analysis: P=3.9 × 10(-9)]. Finally, we observed that ERAP2 protein expression is dependent on the ERAP1 background across three European populations (n = 3353). In conclusion, a functionally distinct combination of ERAP1 and ERAP2 are a hallmark of Birdshot and provide rationale for strategies designed to correct ERAP function for treatment of Birdshot and MHC-I-opathies more broadly.


Assuntos
Aminopeptidases/genética , Predisposição Genética para Doença , Antígenos de Histocompatibilidade Menor/genética , Uveíte/genética , Feminino , Estudos de Associação Genética , Genótipo , Antígenos HLA-A/genética , Antígenos HLA-A/imunologia , Haplótipos/genética , Humanos , Masculino , Locos Secundários de Histocompatibilidade/genética , Polimorfismo de Nucleotídeo Único/genética , Uveíte/imunologia , Uveíte/patologia
2.
BMC Mol Biol ; 18(1): 6, 2017 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-28274199

RESUMO

BACKGROUND: STAT1 and IRF1 collaborate to induce interferon-γ (IFNγ) stimulated genes (ISGs), but the extent to which they act alone or together is unclear. The effect of single nucleotide polymorphisms (SNPs) on in vivo binding is also largely unknown. RESULTS: We show that IRF1 binds at proximal or distant ISG sites twice as often as STAT1, increasing to sixfold at the MHC class I locus. STAT1 almost always bound with IRF1, while most IRF1 binding events were isolated. Dual binding sites at remote or proximal enhancers distinguished ISGs that were responsive to IFNγ versus cell-specific resistant ISGs, which showed fewer and mainly single binding events. Surprisingly, inducibility in one cell type predicted ISG-responsiveness in other cells. Several dbSNPs overlapped with STAT1 and IRF1 binding motifs, and we developed methodology to rapidly assess their effects. We show that in silico prediction of SNP effects accurately reflects altered binding both in vitro and in vivo. CONCLUSIONS: These data reveal broad cooperation between STAT1 and IRF1, explain cell type specific differences in ISG-responsiveness, and identify genetic variants that may participate in the pathogenesis of immune disorders.


Assuntos
Fator Regulador 1 de Interferon/genética , Interferon gama/imunologia , Polimorfismo de Nucleotídeo Único , Fator de Transcrição STAT1/genética , Elementos Facilitadores Genéticos , Genes MHC Classe I , Células HeLa , Humanos , Fator Regulador 1 de Interferon/imunologia , Fator Regulador 1 de Interferon/metabolismo , Locos Secundários de Histocompatibilidade , Ligação Proteica , Fator de Transcrição STAT1/imunologia , Fator de Transcrição STAT1/metabolismo , Regulação para Cima
3.
Immunogenetics ; 63(6): 377-94, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21327606

RESUMO

A major challenge facing studies of major histocompatibility complex (MHC) evolution in birds is the difficulty in genotyping alleles at individual loci, and the consequent inability to investigate sequence variation and selection pressures for each gene. In this study, four MHC class I loci were isolated from the red-billed gull (Larus scopulinus), representing both the first characterized MHCI genes within Charadriiformes (shorebirds, gulls, and allies) and the first full-length MHCI sequences described outside Galloanserae (gamebirds + waterfowl). Complete multilocus genotypes were obtained for 470 individuals using a combination of reference-strand conformation analysis and direct sequencing of gene-specific amplification products, and variation of peptide-binding region (PBR) exons was surveyed for all loci. Each gene is transcribed and has conserved sequence features characteristic of antigen-presenting MHCI molecules. However, higher allelic variation, a more even allele frequency distribution, and evidence of positive selection acting on a larger number of PBR residues suggest that only one locus (Lasc-UAA) functions as a major classical MHCI gene. Lasc-UBA, with more limited variation and PBR motifs that encompass a subset of Lasc-UAA diversity, was assigned a putative minor classical function, whereas the divergent and largely invariant binding-groove motifs of Lasc-UCA and -UDA are suggestive of nonclassical loci with specialized ligand-binding roles.


Assuntos
Charadriiformes/genética , Charadriiformes/imunologia , Genes MHC Classe I , Alelos , Sequência de Aminoácidos , Animais , Proteínas Aviárias/química , Proteínas Aviárias/genética , Proteínas Aviárias/imunologia , Sequência de Bases , Sítios de Ligação/genética , Sequência Conservada , Primers do DNA/genética , DNA Complementar/genética , Evolução Molecular , Éxons , Variação Genética , Antígenos de Histocompatibilidade Classe I/química , Antígenos de Histocompatibilidade Classe I/genética , Complexo Principal de Histocompatibilidade , Locos Secundários de Histocompatibilidade , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase , Ligação Proteica , Estrutura Terciária de Proteína , Seleção Genética , Homologia de Sequência de Aminoácidos , Homologia de Sequência do Ácido Nucleico
5.
J Immunol ; 183(9): 5991-8, 2009 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-19812210

RESUMO

HLA-Cw disparity in a donor increases the risk of acute graft-vs-host disease (GVHD) after bone marrow transplantation. Acute GVHD is mediated by donor CTLs. However, mismatched HLA-Cw-specific CTLs generated in posttransplant recipients who developed acute GVHD have not been characterized in detail. In this study, CTL clones isolated from a recipient at the onset of acute GVHD who was transplanted from an HLA-A, -B, and -DRB1-matched, HLA-Cw-mismatched (recipient, Cw*0303/Cw*0702; donor, Cw*0801/Cw*0702), unrelated donor were characterized. The seven isolated CTLs, including CD4(+), CD8(+), and CD4(+)CD8(+) T lymphocytes, lysed recipient cells, HLA-Cw*0303-transfected 721.211 cells, and HLA-Cw*0303-transfected donor cells, but not untransfected 721.211 cells or donor cells. Thus, all CTLs recognized the mismatched Cw*0303 molecule as an alloantigen. The sequences of Cw*0303 and Cw*0801 differ by 16 aas. Stimulation of CTLs by COS cells transfected with Cw*0303 cDNA constructs demonstrated that Cw*0303 mutants in which individual amino acids constituting peptide-binding pockets were substituted with the corresponding Cw*0801 amino acids significantly decreased IFN-gamma production by all CTLs, whereas Cw*0303 mutants bearing Cw*0801 amino acids outside the positions constituting peptide-binding pockets stimulated all CTLs to the same degree as the wild-type Cw*0303 construct. These data suggest that all CTLs recognized the Cw molecule in a peptide-dependent manner. ELISPOT revealed that Cw*0303-reactive T cells accounted for one-half of the total of alloreactive T cells in the blood during GVHD. Taken together, non-self Cw-specific CTL clones with a variety of phenotypes and peptide specificities can be generated in posttransplant recipients with acute GVHD.


Assuntos
Transplante de Medula Óssea/efeitos adversos , Doença Enxerto-Hospedeiro/imunologia , Antígenos HLA-C , Linfócitos T Citotóxicos/imunologia , Doença Aguda , Adulto , Sequência de Aminoácidos , Apresentação do Antígeno/genética , Transplante de Medula Óssea/imunologia , Células Cultivadas , Células Clonais , Testes Imunológicos de Citotoxicidade , Feminino , Doença Enxerto-Hospedeiro/genética , Antígenos HLA-C/efeitos adversos , Antígenos HLA-C/genética , Humanos , Isoantígenos/genética , Isoantígenos/metabolismo , Locos Secundários de Histocompatibilidade/genética , Dados de Sequência Molecular , Linfócitos T Citotóxicos/metabolismo
6.
J Clin Invest ; 119(9): 2787-94, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19726874

RESUMO

Bone marrow transplantation (BMT) represents a cure for nonmalignant hematological disorders. However, compared with the stringent conditioning regimens used when performing BMT to treat hematological malignancies, the reduced intensity conditioning regimen used in the context of nonmalignant hematological disorders leads to substantially higher rates of BMT rejection, presumably due to an intact immune system. The relevant patient population typically receives transfusion support, often including platelets, and the frequency of BMT rejection correlates with the frequency of transfusion. Here, we demonstrate that immunity to transfused platelets contributes to subsequent BMT rejection in mice, even when the BMT donor and recipient are MHC matched. We used MHC-matched bone marrow because, although immunity to transfused platelets is best characterized in relation to HLA-specific antibodies, such antibodies are unlikely to play a role in clinical BMT rejection that is HLA matched. However, bone marrow is not matched in the clinic for minor histocompatibility antigens, such as those carried by platelets, and we report that transfusion of minor histocompatibility antigen-mismatched platelets induced subsequent BMT rejection. These findings indicate previously unappreciated sequelae of immunity to platelets in the context of transplantation and suggest that strategies to account for minor histocompatibility mismatching may help to reduce the chance of BMT rejection in human patients.


Assuntos
Transplante de Medula Óssea/efeitos adversos , Transplante de Medula Óssea/imunologia , Rejeição de Enxerto/etiologia , Antígenos de Histocompatibilidade Menor/sangue , Transfusão de Plaquetas/efeitos adversos , Animais , Plaquetas/imunologia , Doenças da Medula Óssea/imunologia , Doenças da Medula Óssea/terapia , Feminino , Rejeição de Enxerto/imunologia , Humanos , Isoanticorpos/sangue , Camundongos , Camundongos Congênicos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Locos Secundários de Histocompatibilidade , Condicionamento Pré-Transplante/métodos , Transplante Homólogo
7.
J Exp Med ; 205(12): 2863-72, 2008 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-19001137

RESUMO

Some minor histocompatibility antigens (mHags) are expressed exclusively on patient hematopoietic and malignant cells, and this unique set of antigens enables specific targeting of hematological malignancies after human histocompatability leucocyte antigen (HLA)-matched allogeneic stem cell transplantation (allo-SCT). We report the first hematopoietic mHag presented by HLA class II (HLA-DQA1*05/B1*02) molecules to CD4(+) T cells. This antigen is encoded by a single-nucleotide polymorphism (SNP) in the B cell lineage-specific CD19 gene, which is an important target antigen for immunotherapy of most B cell malignancies. The CD19(L)-encoded antigen was identified using a novel and powerful genetic strategy in which zygosity-genotype correlation scanning was used as the key step for fine mapping the genetic locus defined by pairwise linkage analysis. This strategy was also applicable for genome-wide identification of a wide range of mHags. CD19(L)-specific CD4(+) T cells provided antigen-specific help for maturation of dendritic cells and for expansion of CD8(+) mHag-specific T cells. They also lysed CD19(L)-positive malignant cells, illustrating the potential therapeutic advantages of targeting this novel CD19(L)-derived HLA class II-restricted mHag. The currently available immunotherapy strategies enable the exploitation of these therapeutic effects within and beyond allo-SCT settings.


Assuntos
Antígenos CD19/imunologia , Linfócitos B/imunologia , Linfócitos T CD4-Positivos/imunologia , Genoma Humano , Leucemia de Células B , Locos Secundários de Histocompatibilidade/imunologia , Linfócitos T Citotóxicos/imunologia , Sequência de Aminoácidos , Antígenos CD19/genética , Sequência de Bases , Linfócitos T CD4-Positivos/citologia , Mapeamento Cromossômico , Feminino , Antígenos HLA/genética , Antígenos HLA/imunologia , Antígenos de Histocompatibilidade Classe II/genética , Antígenos de Histocompatibilidade Classe II/imunologia , Humanos , Imunofenotipagem , Leucemia de Células B/genética , Leucemia de Células B/imunologia , Masculino , Locos Secundários de Histocompatibilidade/genética , Dados de Sequência Molecular , Linhagem , Polimorfismo de Nucleotídeo Único , Alinhamento de Sequência
9.
Immunogenetics ; 59(8): 631-9, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17541577

RESUMO

Minor histocompatibility antigens (MiHAs) stimulate the rejection of allografts when donors and recipients are matched at the major histocompatibility complex (MHC). The majority of identified autosomal MiHAs were generated by non-synonymous (NS) substitutions that alter MHC class I-binding peptides. The mosaic distribution of single nucleotide polymorphisms (SNPs) that distinguish inbred mouse strains led us to hypothesize that MiHA genes defined by congenic strains on C57BL/6 and C57BL/10 backgrounds map to chromosomal regions with relatively high numbers of NS SNPs that distinguish C57 strains from other common inbred strains. To test this hypothesis, we mapped the ends of differential chromosome segments of congenic strains, which define 12 MiHAs, relative to microsatellites and SNPs. The lengths of differential segments ranged from 9.7 to 105.9 Mbp in congenic strains where no attempts were made to select recombinants within these segments. There was no apparent correlation between differential segment length and number of backcrosses, suggesting that factors other than the number of opportunities for recombination affected the differential segment lengths in these congenics. These differential segments included higher numbers of NS SNPs that distinguish C57BL/6J from A/J, DBA/2J, and 129S1/J than would be predicted if these SNPs were uniformly distributed along the chromosomes. The most extreme case was the H8 congenic that included 74% of the SNPs on chromosome 14 within its 9.7-11.1 Mbp differential segment. These results point toward a direct relationship between the level of genomic divergence, as indicated by numbers of NS SNPs, and numbers of MiHAs that collectively determine the magnitude of allograft rejection.


Assuntos
Camundongos Congênicos/genética , Camundongos Congênicos/imunologia , Locos Secundários de Histocompatibilidade , Polimorfismo de Nucleotídeo Único , Animais , Mapeamento Cromossômico , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Repetições de Microssatélites , Antígenos de Histocompatibilidade Menor/genética , Especificidade da Espécie
10.
PLoS One ; 1: e42, 2006 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-17183671

RESUMO

BACKGROUND: Minor Histocompatibility (H) antigen mismatches significantly influence the outcome of HLA-matched allogeneic stem cell transplantation. The molecular identification of human H antigens is increasing rapidly. In parallel, clinical application of minor H antigen typing has gained interest. So far, relevant and simple tools to analyze the minor H antigens in a quick and reliable way are lacking. METHODOLOGY AND FINDINGS: We developed a uniform PCR with sequence-specific primers (PCR-SSP) for 10 different autosomal minor H antigens and H-Y. This genomic minor H antigen typing methodology allows easy incorporation in the routine HLA typing procedures. DNA from previously typed EBV-LCL was used to validate the methodology. To facilitate easy interpretation for clinical purposes, a minor H database named dbMinor (http://www.lumc.nl/dbminor) was developed. Input of the minor H antigen typing results subsequently provides all relevant information for a given patient/donor pair and additional information on the putative graft-versus-host, graft-versus-tumor and host-versus-graft reactivities. SIGNIFICANCE: A simple, uniform and rapid methodology was developed enabling determination of minor H antigen genotypes of all currently identified minor H antigens. A dbMinor database was developed to interpret the genomic typing for its potential clinical relevance. The combination of the minor H antigen genomic typing methodology with the online dbMinor database and applications facilitates the clinical application of minor H antigens anti-tumor targets after stem cell transplantation.


Assuntos
Teste de Histocompatibilidade/métodos , Antígenos de Histocompatibilidade Menor/genética , Locos Secundários de Histocompatibilidade , Alelos , Sequência de Bases , Primers do DNA/genética , Bases de Dados Genéticas , Antígeno H-Y/genética , Antígenos HLA/genética , Humanos , Reação em Cadeia da Polimerase/métodos , Transplante de Células-Tronco
12.
Br J Haematol ; 134(4): 406-16, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16822283

RESUMO

Minor histocompatibility antigens (mHags) play crucial roles in the induction of graft versus host disease (GVHD) and/or graft versus leukaemia (GVL) effects following human leucocyte antigen (HLA)-identical haematopoietic stem cell transplantation (HSCT). Using HLA-A*3101- and -A*3303-restricted cytotoxic T lymphocyte (CTL) clones generated from different post-HSCT recipients, we identified two novel mHag epitopes encoded by the leader sequence of cathepsin H (CTSH) isoform a. The nonameric sequence ATLPLLCAR was defined as an HLA-A*3101-restricted epitope (CTSH(R)/A31), while a decameric peptide featuring a one N-terminal amino acid extension, WATLPLLCAR, was presented by HLA-A*3303 (CTSH(R)/A33). The immunogenicity of both epitopes was totally dependent on the polymorphic C-terminal arginine residue and substitution with glycine completely abolished binding to the corresponding HLA molecules. Thus, the immunogenicity of this mHag is exerted by differential HLA binding capacity. CTSH is relatively ubiquitously expressed at protein levels, thus it may be involved in GVHD and anti-leukaemic/tumour responses. Interestingly, however, CTL clones predominantly lysed targets of haematopoietic cell origin, which could not be explained in terms of the immunoproteasome system. Although the mechanisms involved in the differential susceptibility remain to be determined, these data suggest that CTSH-encoded mHags could be targets for GVL effects.


Assuntos
Catepsinas/genética , Cisteína Endopeptidases/genética , Epitopos/imunologia , Antígenos HLA/imunologia , Locos Secundários de Histocompatibilidade/imunologia , Isoformas de Proteínas/genética , Linfócitos T Citotóxicos/imunologia , Doença Aguda , Sequência de Aminoácidos , Sequência de Bases , Catepsina H , Clonagem Molecular , Feminino , Citometria de Fluxo , Doença Enxerto-Hospedeiro/imunologia , Humanos , Leucemia Mieloide/imunologia , Masculino , Microscopia Confocal , Dados de Sequência Molecular , Linhagem , Reação em Cadeia da Polimerase Via Transcriptase Reversa
13.
Immunogenetics ; 58(5-6): 396-406, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16738937

RESUMO

Modo-UG is a class I gene located in the MHC of the marsupial Monodelphis domestica, the gray, short-tailed opossum. Modo-UG is expressed as three alternatively spliced mRNA forms, all of which encode a transmembrane form with a short cytoplasmic tail that lacks phosphorylation sites typically found in classical class I molecules. The three alternative mRNAs would encode a full-length form, an isoform lacking the alpha2 domain, and one lacking both alpha2 and alpha3 domains. Genotyping both captive-bred and wild M. domestica from different geographic regions revealed no variation in the residues that make up Modo-UG's peptide-binding groove. Modo-UG's low polymorphism is contrasting to that of a nearby class I locus, Modo-UA1, which has a highly polymorphic peptide-binding region. Absence of functional polymorphism in Modo-UG is therefore not a general feature of opossum class I genes but the result of negative selection. Modo-UG is the first MHC linked marsupial class I to be described that appears to clearly have nonclassical features.


Assuntos
Genes MHC Classe I/genética , Antígenos de Histocompatibilidade Classe I/genética , Locos Secundários de Histocompatibilidade/genética , Monodelphis/imunologia , Polimorfismo Genético , Processamento Alternativo , Sequência de Aminoácidos , Animais , Antígenos de Histocompatibilidade Classe I/classificação , Dados de Sequência Molecular , Monodelphis/genética , Filogenia , RNA Mensageiro/metabolismo
14.
Tissue Antigens ; 68(1): 62-5, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16774541

RESUMO

The polymorphic minor histocompatibility antigen HA-1 induces powerful T-cell alloreactivities with important consequences for graft-vs-tumor activity and development of graft-vs-host disease in patients after human leukocyte antigen-matched stem-cell transplantation (SCT). In view of possible translational animal studies, we analyzed the evolutionary conservation of the diallelic HA-1 locus in four mammalian species. Our results show that rodents do not encode the HA-1(H) allele, neither show polymorphism in this position on the HA-1 gene. Contrariwise, the HA-1(H) allele is present in non-human primate species and dogs. Interestingly, both the HA-1(H) T-cell epitope and its non-immunogenic counterpart HA-1(R) are present in the latter species. Thus, the HA-1 allelic polymorphism is conserved in evolution in primates and dogs.


Assuntos
Alelos , Evolução Molecular , Macaca mulatta/genética , Antígenos de Histocompatibilidade Menor/genética , Locos Secundários de Histocompatibilidade , Pan troglodytes/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Sequência Conservada , Cães , Heterozigoto , Homozigoto , Antígenos de Histocompatibilidade Menor/química , Dados de Sequência Molecular , Oligopeptídeos , Ratos
15.
Blood ; 107(9): 3779-86, 2006 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-16391015

RESUMO

Minor histocompatibility antigens (mHAg's) are peptides encoded by polymorphic genes that are presented by major histocompatibility complex (MHC) molecules and recognized by T cells in recipients of allogeneic hematopoietic cell transplants. Here we report that an alternative transcript of the proliferation-associated nuclear element 1 (PANE1) gene encodes a novel human leukocyte antigen (HLA)-A(*)0301-restricted mHAg that is selectively expressed in B-lymphoid cells. The antigenic peptide is entirely encoded within a unique exon not present in other PANE1 transcripts. Sequencing of PANE1 alleles in mHAg-positive and mHAg-negative cells demonstrates that differential T-cell recognition is due to a single nucleotide polymorphism within the variant exon that replaces an arginine codon with a translation termination codon. The PANE1 transcript that encodes the mHAg is expressed at high levels in resting CD19(+) B cells and B-lineage chronic lymphocytic leukemia (B-CLL) cells, and at significantly lower levels in activated B cells. Activation of B-CLL cells through CD40 ligand (CD40L) stimulation decreases expression of the mHAg-encoding PANE1 transcript and reciprocally increases expression of PANE1 transcripts lacking the mHAg-encoding exon. These studies suggest distinct roles for different PANE1 isoforms in resting compared with activated CD19(+) cells, and identify PANE1 as a potential therapeutic target in B-CLL.


Assuntos
Linfócitos B/imunologia , Leucemia Linfocítica Crônica de Células B/genética , Leucemia Linfocítica Crônica de Células B/imunologia , Antígenos de Histocompatibilidade Menor/genética , Locos Secundários de Histocompatibilidade , Proteínas Nucleares/genética , Proteínas Nucleares/imunologia , Processamento Alternativo , Sequência de Aminoácidos , Antígenos CD19/metabolismo , Sequência de Bases , Proteínas de Ciclo Celular , DNA/genética , Epitopos/química , Expressão Gênica , Antígenos HLA-A/genética , Antígeno HLA-A3 , Humanos , Ativação Linfocitária , Antígenos de Histocompatibilidade Menor/química , Dados de Sequência Molecular , Proteínas Nucleares/química , Espectrometria de Massas por Ionização por Electrospray , Linfócitos T Citotóxicos/imunologia
16.
Arthritis Rheum ; 50(8): 2695-705, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15334486

RESUMO

OBJECTIVE: To identify additional sex-specific and epistatic quantitative trait loci (QTL) regulating collagen-induced arthritis (CIA) severity overall, as well as within different stages during the disease course, in an intercross between major histocompatibility complex-identical inbred rat strains DA/Bkl (susceptible) and ACI/Hsd (resistant). METHODS: Arthritic male (DA x ACI)F2 intercross offspring (n = 143) were analyzed separately from the females (n = 184). Phenotypic extremes (maximum arthritis scores [MAS]) were genotyped and used for QTL analysis. All 327 rats were genotyped with the simple sequence-length polymorphism (SSLP) markers closest to the peak of Cia7 and Cia10, the major loci previously identified in this intercross, and with SSLPs covering chromosomes 12 and 18. Phenotypes studied were disease onset, arthritis severity scores on days 14-39, MAS, mean and cumulative arthritis scores, delayed-type hypersensitivity, and antibody responses to rat type II collagen. RESULTS: A new female-specific arthritis-severity recessive locus was identified on rat chromosome 12 (Cia25), with a maximum effect observed on day 28 (logarithm of odds [LOD] 4.7). The homozygous DA genotype at Cia25 was associated with a 45% higher median arthritis score in females. Sequencing analyses of the Cia25 candidate gene Ncf1 revealed polymorphisms between DA and ACI. The previously identified locus, Cia10, was found to be male-specific. A 2-locus interaction model analysis identified a novel recessive chromosome 18 QTL, Cia26, which was dependent on Cia7, with its maximum effect observed at later stages during the disease course (peak LOD score of 3.6 for arthritis scores on day 39). CONCLUSION: This study identified 2 novel female-specific loci, and 1 male-specific locus. Cia25 regulates MAS and disease severity during the mid-to-late stages of the disease course and may be accounted for by Ncf1 polymorphisms. Cia26 is in epistasis with Cia7 and regulates later stages of disease, suggesting an involvement in disease perpetuation and/or chronicity.


Assuntos
Artrite Experimental/genética , Epistasia Genética , Locos Secundários de Histocompatibilidade/genética , Animais , Doença Crônica , Cruzamentos Genéticos , Feminino , Genótipo , Masculino , Fenótipo , Ratos , Índice de Gravidade de Doença , Fatores Sexuais
17.
J Immunol ; 172(8): 4762-9, 2004 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-15067052

RESUMO

Wild-type mice immunized with MART-1 melanoma Ag-engineered dendritic cells (DC) generate strong Ag-specific immunity that has an absolute requirement for both CD8(+) and CD4(+) T cells. DC administration to CD8 alpha knockout mice displayed unexpectedly enhanced levels of protection to tumor challenge despite this deficiency in CD8(+) T cells and the inability to mount MHC class I-restricted immune responses. This model has the following features: 1) antitumor protection is Ag independent; 2) had an absolute requirement for CD4(+) and NK1.1(+) cells; 3) CD4(+) splenocytes are responsible for cytokine production; 4) lytic cells in microcytotoxicity assays express NK, but lack T cell markers (NK1.1(+) alpha beta TCR(-) CD3(-)); and 5) the lytic phenotype can be transferred to naive CD8 alpha knockout mice by NK1.1(+) splenocytes. Elucidation of the signaling events that activate these effective cytotoxic cells and the putative suppressive mechanisms in a wild-type environment may provide means to enhance the clinical activity of DC-based approaches.


Assuntos
Antígenos CD8/genética , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Células Dendríticas/imunologia , Células Dendríticas/transplante , Imunoterapia Adotiva/métodos , Melanoma Experimental/imunologia , Melanoma Experimental/prevenção & controle , Proteínas , Adenovírus Humanos/genética , Animais , Antígenos/biossíntese , Antígenos Ly , Antígenos de Neoplasias , Antígenos de Superfície , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Linhagem Celular Tumoral , Células Cultivadas , Testes Imunológicos de Citotoxicidade , Células Dendríticas/virologia , Epitopos de Linfócito T/genética , Teste de Histocompatibilidade , Humanos , Imunofenotipagem , Interferon gama/biossíntese , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/metabolismo , Lectinas Tipo C , Ativação Linfocitária/imunologia , Depleção Linfocítica , Linfopenia/genética , Linfopenia/imunologia , Antígeno MART-1 , Melanoma Experimental/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Locos Secundários de Histocompatibilidade/genética , Subfamília B de Receptores Semelhantes a Lectina de Células NK , Proteínas de Neoplasias/administração & dosagem , Proteínas de Neoplasias/genética , Biossíntese de Proteínas , Baço/citologia , Baço/imunologia , Baço/transplante
18.
Lancet ; 362(9384): 610-5, 2003 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-12944060

RESUMO

BACKGROUND: Stem-cell grafts between HLA-identical siblings are less likely to succeed when there is a sex mismatch. This lack of success can be interpreted as enhanced activity directed against minor histocompatibility antigens encoded by the Y chromosome (H-Y). So far, in man, only cytotoxic T lymphocytes (CTLs) specific for several minor histocompatibility antigens have been reported. We aimed to identify and clarify the role of MHC class II-restricted H-Y-specific T-helper cells in these transplant settings. METHODS: H-Y-specific MHC class II-restricted CD4+ T cells were isolated from blood of a female patient who rejected an HLA-identical male stem-cell transplant. By molecular cloning of H-Y genes and functional T-helper experiments, we elucidated antigen specificity and the functional properties of these H-Y-specific T-helper cells. FINDINGS: CD4+ T-helper cells recognise the Y gene-encoded peptide VIKVNDTVQI presented by HLA-DRbeta3*0301. These T-helper cells mature dendritic cells and enhance expansion of minor histocompatibility antigen-specific MHC class I-restricted CD8+ CTLs. INTERPRETATION: Characterisation of an MHC class II-restricted H-Y epitope that evoked CD4+ T-helper responses adds a novel cellular component to the alloimmune response against Y chromosome-encoded minor histocompatibility antigens. This component completes the H-Y-directed alloimmune response and aids understanding of the poorer outcome of sex-mismatched transplants.


Assuntos
Antígenos CD4/imunologia , Epitopos de Linfócito T/imunologia , Antígeno H-Y/imunologia , Transplante de Células-Tronco , Linfócitos T Auxiliares-Indutores/imunologia , Imunologia de Transplantes/imunologia , Adulto , Anemia Aplástica/cirurgia , Cromossomos Humanos Y/imunologia , Mapeamento de Epitopos , Feminino , Genes sry/imunologia , Rejeição de Enxerto/imunologia , Antígenos de Histocompatibilidade Classe II/imunologia , Humanos , Masculino , Locos Secundários de Histocompatibilidade/imunologia , Processos de Determinação Sexual , Fatores Sexuais
19.
Transplantation ; 76(1): 84-91, 2003 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-12865791

RESUMO

BACKGROUND: Minor histocompatibility antigen (mHag) discordances have been shown to play a critical role in graft-versus-host disease after bone marrow transplantation. However, the role of mHag in rejection of solid-organ allografts remains unknown. Therefore, the goal of this study was to define the role of a single mHag discordance derived from the polymorphic H13 allele in the development of cardiac allograft rejection in mice. The H13a and H13b alleles encode for the SSVVGVWYL (SVL9) and SSVIGVWYL (SIL9) mHag bound to the H2Db molecule, respectively. METHODS: C56BL/10SnJ (H13a) cardiac allografts were transplanted into congenic B10.CE-H13b Aw(30NX)/Sn (H13b) mice. Allograft function was monitored daily and rejection was defined by cessation of heart beat. Rejection was confirmed histologically. The phenotypic and functional characteristics of the graft-infiltrating cells were analyzed by in situ and in vitro staining with H13a-specific tetramers and by chromium-51 (51Cr)-release assay, respectively. RESULTS: Sixty-five percent of H13-incompatible allografts were rejected in 37.0+/-14.5 days. Sixty-eight percent of the H13a allografts transplanted into H13a-sensitized mice were rejected earlier, in 27.6+/-15.9 days. Rejected allografts showed histopathologic signs of chronic rejection with diffuse mononuclear cell infiltration, concentric intimal hyperplasia, and fibrosis. Both CD8+ (87%) and CD4+ (13%) T cells were observed in rejected allografts. In addition, 60% of the graft-infiltrating CD8+ T cells recognized a H2Db/SVL9 tetramer. Graft-infiltrating CD8+ T cells showed a significant H2Db-restricted, SVL9-specific cytotoxic activity. CONCLUSIONS: A single mHag discordance, as demonstrated with H13 disparity, results in the pathogenesis of chronic rejection of major histocompatibility complex-matched vascularized solid-organ allograft.


Assuntos
Rejeição de Enxerto/imunologia , Transplante de Coração/imunologia , Antígenos de Histocompatibilidade Menor/imunologia , Linfócitos T Citotóxicos/imunologia , Animais , Linfócitos T CD4-Positivos/imunologia , Modelos Animais de Doenças , Regulação da Expressão Gênica/imunologia , Rejeição de Enxerto/patologia , Transplante de Coração/patologia , Interferon gama/genética , Interleucinas/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos , Locos Secundários de Histocompatibilidade , Linfócitos T Citotóxicos/patologia , Transplante Homólogo/imunologia , Transplante Isogênico/imunologia
20.
J Immunol ; 170(10): 5133-42, 2003 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-12734360

RESUMO

Minor histocompatibility (H) Ag disparities result in graft-vs-host disease and chronic solid allograft rejection in MHC-identical donor-recipient combinations. Minor H Ags are self protein-derived peptides presented by MHC class I molecules. Most arise as a consequence of allelic variation in the bound peptide (p) that results in TCR recognizing the p/MHC as foreign. We used a combinational peptide screening approach to identify the immune dominant H2K(b)-restricted epitope defining the mouse H4(b) minor H Ag. H4(b) is a consequence of a P3 threonine to isoleucine change in the MHC-bound peptide derived from epithelial membrane protein-3. This allelic variation also leads to phosphorylation of the H4(b) but not the H4(a) epitope. Further, ex vivo CD8(+) T lymphocytes bind phosphorylated Ag tetramers with high efficiency. Although we document the above process in the minor H Ag system, posttranslational modifications made possible by subtle amino acid changes could also contribute to immunogenicity and immune dominance in tumor immunotherapeutic settings.


Assuntos
Antígenos H-2/genética , Antígenos H-2/metabolismo , Glicoproteínas de Membrana , Locos Secundários de Histocompatibilidade/genética , Processamento de Proteína Pós-Traducional/genética , Processamento de Proteína Pós-Traducional/imunologia , Substituição de Aminoácidos/imunologia , Animais , Técnicas de Química Combinatória , Sequência Conservada/imunologia , Epitopos de Linfócito T/genética , Epitopos de Linfócito T/metabolismo , Humanos , Epitopos Imunodominantes/genética , Epitopos Imunodominantes/metabolismo , Isoleucina/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Antígenos de Histocompatibilidade Menor/genética , Antígenos de Histocompatibilidade Menor/metabolismo , Mimetismo Molecular , Oligopeptídeos/genética , Oligopeptídeos/metabolismo , Biblioteca de Peptídeos , Fosfopeptídeos/genética , Fosfopeptídeos/metabolismo , Treonina/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA