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1.
Med Hypotheses ; 130: 109267, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31383332

RESUMO

Presentation of many unwanted epitopes within tetanus toxoid vaccine to lymphocyte clones may lead to production of many unwanted antibodies. Moreover an ideal vaccine must cover all individuals in a population that is dependent to the kinds of human leukocyte antigen alleles. Concerning these issues, our study was aimed to in silico design of a multi-epitope tetanus vaccine (METV) in order to improve population coverage and protectivity of tetanus vaccine as well as reduction of complications. Concerning these issues, a novel rational filtration was implemented to design a novel METV using immunoinformatics and surface epitope mapping approaches. Prediction of epitopes for tetanus toxin was performed in the candidate country in which the frequency had been gathered from almost all geographical distributions. The most strong binder epitopes for major histocompatibility complex class II were selected and among them the surface epitopes of native toxin were selected. The population coverage of the selected epitopes was estimated. The final candidate epitopes had highly population coverage. Molecular docking was performed to prediction of binding affinity of our candidate epitopes to the HLA-DRB1 alleles. At first, 680 strong binder epitopes were predicted. Among them 11 epitopes were selected. Finally, 4 epitopes had the most population coverage and suggested as a tetra-epitope tetanus vaccine. 99.41% of inessential strong binders were deleted using our tree steps filtration. HLA-DP had the most roles in epitope presentation. Molecular docking analysis proved the strong binding affinity of candidate epitopes to the HLA-DRB1 alleles. In conclusion, we theoretically reduced 99.41% of unwanted antibodies using our novel filtration strategies. Our tetra-epitope tetanus vaccine showed 100% population coverage in the candidate country. Furthermore, it was demonstrated that HLA-DP and HLA-DQ had more potential in epitope presentation in comparison to HLA-DRB1.


Assuntos
Mapeamento de Epitopos/métodos , Antígenos HLA/imunologia , Toxoide Tetânico/química , Alelos , Alergia e Imunologia/instrumentação , Biologia Computacional , Desenho de Fármacos , Epitopos , Antígenos HLA-DP/imunologia , Antígenos HLA-DQ/imunologia , Cadeias HLA-DRB1/imunologia , Humanos , Conformação Molecular , Simulação de Acoplamento Molecular
2.
Nat Immunol ; 20(9): 1129-1137, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31358998

RESUMO

Natural killer (NK) cells can recognize virus-infected and stressed cells1 using activating and inhibitory receptors, many of which interact with HLA class I. Although early studies also suggested a functional impact of HLA class II on NK cell activity2,3, the NK cell receptors that specifically recognize HLA class II molecules have never been identified. We investigated whether two major families of NK cell receptors, killer-cell immunoglobulin-like receptors (KIRs) and natural cytotoxicity receptors (NCRs), contained receptors that bound to HLA class II, and identified a direct interaction between the NK cell receptor NKp44 and a subset of HLA-DP molecules, including HLA-DP401, one of the most frequent class II allotypes in white populations4. Using NKp44ζ+ reporter cells and primary human NKp44+ NK cells, we demonstrated that interactions between NKp44 and HLA-DP401 trigger functional NK cell responses. This interaction between a subset of HLA-DP molecules and NKp44 implicates HLA class II as a component of the innate immune response, much like HLA class I. It also provides a potential mechanism for the described associations between HLA-DP subtypes and several disease outcomes, including hepatitis B virus infection5-7, graft-versus-host disease8 and inflammatory bowel disease9,10.


Assuntos
Antígenos HLA-DP/imunologia , Imunidade Inata/imunologia , Células Matadoras Naturais/imunologia , Receptor 2 Desencadeador da Citotoxicidade Natural/imunologia , Linhagem Celular , Doença Enxerto-Hospedeiro/imunologia , Hepatite B/imunologia , Humanos , Doenças Inflamatórias Intestinais/imunologia , Células Jurkat
3.
Turk J Gastroenterol ; 30(7): 616-623, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31290749

RESUMO

BACKGROUND/AIMS: About 400 million people worldwide have been exposed to Hepatitis B (HBV) infection. A range of 10%-15% of chronic HBV carriers may present with various liver diseases including cirrhosis and hepatic cancer. The chronicity or clearance of HBV infection is dependent on viral and genetic variables. Genome-wide association studies (GWAS) have reported that the variants of human leukocyte antigen (HLA), rs3128917 and rs9380343, are significantly related to persistent HBV infection. HLA molecules are responsible for introducing various antigens into the immune system. These variants might affect antigen presentation by influencing HLA mRNA expression, therefore, antigen presentation may not be performed properly. This study aims to assess the relationship of HLA gene variants to chronic HBV infection. MATERIALS AND METHODS: HLA variants were explored in 238 chronic HBV patients and in 238 individuals with spontaneous clearance of HBV using PCR-RFLP assay. RESULTS: The allele and genotype of rs9380343 polymorphism were associated with persistent HBV infection risk (allele: p=0.038, genotype: p=0.029), but rs3128917 polymorphism was not significant. Additionally, rs9380343 polymorphism was also related to increased risk of HBV infection in males (p<0.05). CONCLUSION: The current study is the first report demonstrating the HLA rs9380343 polymorphism as a genetic risk factor for chronicity of HBV infection. Further independent studies are required to confirm the current findings using a larger sample size in different populations.


Assuntos
Antígenos HLA-DP/genética , Hepatite B Crônica/genética , Polimorfismo de Nucleotídeo Único , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Alelos , Feminino , Genótipo , Antígenos HLA-DP/imunologia , Hepatite B Crônica/imunologia , Humanos , Masculino , Pessoa de Meia-Idade , Turquia
4.
Blood Adv ; 3(9): 1429-1440, 2019 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-31053570

RESUMO

The immunogenicity of protein therapeutics is an important safety and efficacy concern during drug development and regulation. Strategies to identify individuals and subpopulations at risk for an undesirable immune response represent an important unmet need. The major histocompatibility complex (MHC)-associated peptide proteomics (MAPPs) assay directly identifies the presence of peptides derived from a specific protein therapeutic on a donor's MHC class II (MHC-II) proteins. We applied this technique to address several questions related to the use of factor VIII (FVIII) replacement therapy in the treatment of hemophilia A (HA). Although >12 FVIII therapeutics are marketed, most fall into 3 categories: (i) human plasma-derived FVIII (pdFVIII), (ii) full-length (FL)-recombinant FVIII (rFVIII; FL-rFVIII), and (iii) B-domain-deleted rFVIII. Here, we investigated whether there are differences between the FVIII peptides found on the MHC-II proteins of the same individual when incubated with these 3 classes. Based on several observational studies and a prospective, randomized, clinical trial showing that the originally approved rFVIII products may be more immunogenic than the pdFVIII products containing von Willebrand factor (VWF) in molar excess, it has been hypothesized that the pdFVIII molecules yield/present fewer peptides (ie, potential T-cell epitopes). We have experimentally tested this hypothesis and found that dendritic cells from HA patients and healthy donors present fewer FVIII peptides when administered pdFVIII vs FL-rFVIII, despite both containing the same molar VWF excess. Our results support the hypothesis that synthesis of pdFVIII under physiological conditions could result in reduced heterogeneity and/or subtle differences in structure/conformation which, in turn, may result in reduced FVIII proteolytic processing relative to FL-rFVIII.


Assuntos
Células Dendríticas/imunologia , Fator VIII/imunologia , Hemofilia A/imunologia , Peptídeos/metabolismo , Células Dendríticas/citologia , Células Dendríticas/metabolismo , Epitopos/química , Epitopos/imunologia , Fator VIII/química , Fator VIII/uso terapêutico , Antígenos HLA-DP/química , Antígenos HLA-DP/metabolismo , Antígenos HLA-DQ/química , Antígenos HLA-DQ/metabolismo , Antígenos HLA-DR/química , Antígenos HLA-DR/metabolismo , Hemofilia A/tratamento farmacológico , Humanos , Leucócitos Mononucleares/citologia , Mapeamento de Peptídeos , Peptídeos/química , Fator de von Willebrand/química , Fator de von Willebrand/metabolismo
5.
Rheumatology (Oxford) ; 58(11): 1942-1949, 2019 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-30938436

RESUMO

OBJECTIVES: This study aimed to characterize the association between HLA alleles and ANCA-associated vasculitis (AAV) in a genetically homogeneous population, and to analyse the contribution of specific HLA molecule amino acid sequences to the risk of AAV. METHODS: We included 187 Danish patients with AAV and 1070 healthy controls. All were HLA typed at two-field resolution. The association of HLA alleles to PR3- or MPO-AAV was analysed. The contribution of the dominant molecular motifs of the HLA-DPB1 molecule to the risk of AAV was investigated by association studies that included specific amino acid sequences of the hypervariable regions in exon 2. RESULTS: Ninety-four percent of patients with PR3-AAV were carriers of HLA-DPB1*04:01 while all patients with PR3-AAV were carriers of an HLA-DPB1*04 allele, and 85% were homozygous. This was significantly more than in the control group (P < 0.0001). The association was even stronger when HLA-DPB1*04:02 and -DPB1*23:01 were included. HLA-DPB1*04:01, -DPB1*04:02 and -DPB1*23:01 share amino acids in positions 8-9, 69, 76 and 84-87 within the hypervariable regions, but only positions 69 and 84-87 contributed significantly to the disease risk. HLA-DRB1*15 was associated with an increased risk of developing PR3-AAV, while HLA-DRB1*04, -DRB1*07 and -DQB1*03 were associated with a reduced risk of kidney involvement in PR3-AAV. MPO-AAV was only weakly associated with HLA class I alleles. CONCLUSION: PR3-AAV is strongly associated with the HLA-DPB1 alleles HLA-DPB1*04:01, -DPB1*04:02 and -DPB1*23:01, which share amino acid sequences crucial for the peptide-binding groove.


Assuntos
Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/genética , Predisposição Genética para Doença/genética , Antígenos HLA-DP/genética , Mieloblastina/genética , Peroxidase/genética , Adulto , Idoso , Alelos , Motivos de Aminoácidos/genética , Estudos de Casos e Controles , Dinamarca , Grupo com Ancestrais do Continente Europeu/genética , Éxons , Feminino , Genótipo , Cadeias HLA-DRB1/genética , Homozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Sistema de Registros , Estudos Retrospectivos , Fatores de Risco
6.
Haematologica ; 104(1): 197-206, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30237261

RESUMO

Stem cell grafts from 10/10 HLA-matched unrelated donors are often mismatched for HLA-DP. In some patients, donor T-cell responses targeting the mismatched HLA-DP allele(s) have been found to induce a specific graft-versus-leukemia effect without coinciding graft-versus-host disease, whereas in other cases significant graft-versus-host disease occurred. Cell-lineage-specific recognition patterns within the allogeneic HLA-DP-specific donor T-cell repertoire could explain the differential clinical effects mediated by donor T cells after HLA-DP-mismatched allogeneic stem cell transplantation. To unravel the composition of the HLA-DP T-cell repertoire, donor T-cell responses were provoked by in vitro stimulation with allogeneic HLA-DP-mismatched monocyte-derived dendritic cells. A strategy including depletion of reactivity against autologous dendritic cells allowed efficient identification and enrichment of allo-reactive T cells upon stimulation with HLA-DP-mismatched dendritic cells. In this study we elucidated that the allogeneic HLA-DP-restricted T-cell repertoire contained T cells with differential cell-lineage-specific recognition profiles. As expected, some of the allogeneic HLA-DP-restricted T cells showed broad recognition of a variety of hematopoietic and non-hematopoietic cell types expressing the targeted mismatched HLA-DP allele. However, a significant proportion of the allogeneic HLA-DP-restricted T cells showed restricted recognition of hematopoietic cells, including primary malignant cells, or even restricted recognition of only myeloid cells, including dendritic cells and primary acute myeloid leukemia samples, but not of other hematopoietic and non-hematopoietic cell types. These data demonstrate that the allogeneic HLA-DP-specific T-cell repertoire contains T cells that show restricted recognition of hematopoietic cells, which may contribute to the specific graft-versus-leukemia effect without coinciding graft-versus-host disease.


Assuntos
Células Dendríticas/imunologia , Doença Enxerto-Hospedeiro/imunologia , Efeito Enxerto vs Leucemia/imunologia , Antígenos HLA-DP/imunologia , Neoplasias Hematológicas/imunologia , Linfócitos T/imunologia , Adulto , Células Dendríticas/patologia , Feminino , Doença Enxerto-Hospedeiro/patologia , Neoplasias Hematológicas/patologia , Neoplasias Hematológicas/terapia , Transplante de Células-Tronco Hematopoéticas , Humanos , Linfócitos T/patologia , Transplante Homólogo
7.
Immunogenetics ; 71(1): 13-23, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30159708

RESUMO

Chimpanzees have been used for some time as an animal model in research on immune-related diseases in humans. The major histocompatibility complex (MHC) region of the chimpanzee has also been the subject of studies in which the attention was mainly on the class I genes. Although full-length sequence information is available on the DRB region genes, such detailed information is lacking for the other class II genes and, if present, is based mainly on exon 2 sequences. In the present study, full-length sequencing was performed on DQ, DP, and DRA genes in a cohort of 67 pedigreed animals, thereby allowing a thorough analysis of the MHC class II repertoire. The results demonstrate that the number of MHC class II lineages and alleles is relatively low, whereas haplotype diversity (combination of genes/alleles on a chromosome) seems to have been maximised by crossing-over processes.


Assuntos
Genes MHC da Classe II , Haplótipos , Pan troglodytes/genética , Alelos , Animais , Variação Genética , Antígenos HLA-DP/genética , Antígenos HLA-DQ/genética , Antígenos HLA-DR/genética , Pan troglodytes/imunologia
8.
Trends Immunol ; 39(12): 960-964, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30416081

RESUMO

Polymorphisms in HLA-DP can modulate interactions with the invariant chain chaperone, contributing independently to differences in the peptide repertoire presented on DP. The resulting presentation of intracellular antigens directly to CD4+ T cells may partly explain genetic and clinical studies describing previously unexplained links between polymorphism in DP and disease.


Assuntos
Apresentação do Antígeno/imunologia , Antígenos HLA-DP/imunologia , Linfócitos T CD4-Positivos/imunologia , Antígenos HLA-DP/genética , Humanos , Peptídeos/imunologia , Polimorfismo Genético/genética , Polimorfismo Genético/imunologia
9.
Molecules ; 23(11)2018 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-30463372

RESUMO

MOTIVATION: Extensive efforts have been devoted to understanding the antigenic peptides binding to MHC class I and II molecules since they play a fundamental role in controlling immune responses and due their involvement in vaccination, transplantation, and autoimmunity. The genes coding for the MHC molecules are highly polymorphic, and it is difficult to build computational models for MHC molecules with few know binders. On the other hand, previous studies demonstrated that some MHC molecules share overlapping peptide binding repertoires and attempted to group them into supertypes. Herein, we present a framework of the utility of supertype clustering to gain more information about the data to improve the prediction accuracy of class II MHC-peptide binding. RESULTS: We developed a new method, called superMHC, for class II MHC-peptide binding prediction, including three MHC isotypes of HLA-DR, HLA-DP, and HLA-DQ, by using supertype clustering in conjunction with RLS regression. The supertypes were identified by using a novel repertoire dissimilarity index to quantify the difference in MHC binding specificities. The superMHC method achieves the state-of-the-art performance and is demonstrated to predict binding affinities to a series of MHC molecules with few binders accurately. These results have implications for understanding receptor-ligand interactions involved in MHC-peptide binding.


Assuntos
Antígenos de Histocompatibilidade Classe II/química , Antígenos de Histocompatibilidade Classe II/metabolismo , Peptídeos/metabolismo , Sítios de Ligação , Análise por Conglomerados , Biologia Computacional/métodos , Antígenos HLA-DP/química , Antígenos HLA-DP/metabolismo , Antígenos HLA-DQ/química , Antígenos HLA-DQ/metabolismo , Antígenos HLA-DR/química , Antígenos HLA-DR/metabolismo , Ligação Proteica
10.
Hum Immunol ; 79(12): 821-822, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30278218

RESUMO

DNA sequence-based typing at the HLA-A, -B, -C, -DPB1, -DQA1, -DQB1, and -DRB1 loci was performed on 496 healthy adult donors from San Diego, California, to characterize allele frequencies in support of studies of T cell responses to common allergens. Deviations from Hardy Weinberg proportions were detected at each locus except A and C. Several alleles were found in more than 15% of individuals, including the class II alleles DPB1∗02:01, DPB1∗04:01, DQA1∗01:02, DQA1∗05:01, DQB1∗03:01, and the class I allele A∗02:01. Genotype data will be available in the Allele Frequencies Net Database (AFND 3562).


Assuntos
Antígenos HLA-A/genética , Antígenos HLA-B/genética , Antígenos HLA-C/genética , Antígenos HLA-DP/genética , Antígenos HLA-DQ/genética , Antígenos HLA-DR/genética , Adolescente , Adulto , Alelos , California , Feminino , Frequência do Gene , Genótipo , Técnicas de Genotipagem/métodos , Teste de Histocompatibilidade/métodos , Humanos , Desequilíbrio de Ligação , Masculino , Pessoa de Meia-Idade , Análise de Sequência de DNA/métodos , Linfócitos T/imunologia , Linfócitos T/metabolismo , Adulto Jovem
11.
Transplant Proc ; 50(8): 2548-2552, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30316396

RESUMO

The presence of isolated de novo anti-DP antibodies is uncommon, making it difficult to determine the impact of anti-DP antibodies on graft outcome. We describe a case of acute antibody-mediated rejection mediated by de novo donor-specific anti-HLA-DP antibodies. Furthermore, the generation of non-donor-specific anti-DP antibodies (NDSAs) detected in the patient's sera was investigated. An 18-year-old woman with pretransplant 0% panel-reactive antibody received kidney transplantation from a living donor. She experienced combined acute T-cell-mediated and antibody-mediated rejection at 15 months after transplantation. High resolution HLA typing of the donor and the patient revealed that they were mismatched at both DPB1 (DPB1*31:01) and DPA1 (DPA1*02:02) loci. The single antigen bead (SAB) testing of patient's sera revealed antibodies against donor's DPB1*31:01 and DPA1*02:02 alleles. Antibodies against several non-donor-specific DP antigens were also detected. No antibodies against other HLA class I and II antigens were detected. In order to explain the reactivity pattern of NDSAs, HLAMatchmaker program was used to identify immunizing eplets shared between donor alleles and reactive beads. The analysis showed 84DEAV, a DPB1 eplet, as a shared eplet found on DPB1*31:01 (mismatched donor allele) and on DPB1-reactive alleles in SAB assay. Additionally, 50RA, a DPA1 eplet, was identified as a shared eplet found on DPA1*02:02 (mismatched donor allele) and on DPA1-reactive alleles in SAB assay. This case highlights the clinical significance of HLA-DP antibodies. Furthermore, the generation of NDSA anti-DP antibodies by epitope sharing underscores the importance of HLA-DP epitope matching in kidney transplantation.


Assuntos
Anticorpos/sangue , Rejeição de Enxerto/imunologia , Antígenos HLA-DP/imunologia , Teste de Histocompatibilidade , Transplante de Rim , Adolescente , Epitopos/imunologia , Feminino , Humanos , Imunologia de Transplantes/imunologia
12.
Transpl Immunol ; 51: 58-61, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30237092

RESUMO

HLA antigens, including HLA-A, B, C, DR and DQ have long been known to have an effect on transplant outcome. Presence of antibodies to these antigens is detrimental to transplant outcome as it ends up to either acute or chronic humoral rejection depending on the titer of the antibodies to these antigens. However, the role of HLA-DP is not fully clear, predominantly due to lack of adequate publications and the fact that DP antigen and antibody detection became possible with the advent of new beads technology. As a results, allocation system has not yet included HA-DP antibodies in virtual crossmatching. This report presents two novel cases with strong HLA-DP antibodies which resulted in acute humoral rejection (AMR).


Assuntos
Rejeição de Enxerto/imunologia , Antígenos HLA-DP/imunologia , Separação Imunomagnética/métodos , Isoanticorpos/sangue , Transplante de Rim , Idoso , Tipagem e Reações Cruzadas Sanguíneas , Feminino , Sobrevivência de Enxerto , Teste de Histocompatibilidade , Humanos , Imunidade Humoral , Masculino , Pessoa de Meia-Idade , Transplante Homólogo
13.
Sci Rep ; 8(1): 4804, 2018 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-29555965

RESUMO

While the principles of classical antigen presentation via MHC class II are well-established, the mechanisms for the many routes of cross-presentation by which endogenous antigens become associated with class II molecules are not fully understood. We have recently demonstrated that the single amino acid polymorphism HLA-DPß84Gly (DP84Gly) is critical to abrogate class II invariant chain associated peptide (CLIP) region-mediated binding of invariant chain (Ii) to DP, allowing endoplasmic reticulum (ER)-resident endogenous antigens to constitutively associate with DP84Gly such as DP4. In this study, we demonstrate that both the CLIP and N-terminal non-CLIP Ii regions cooperatively generate an Ii conformation that cannot associate with DP84Gly via the CLIP region. We also demonstrate the ability of DP4 to efficiently process and present antigens encoded in place of CLIP in a chimeric Ii, regardless of wild type Ii and HLA-DM expression. These data highlight the complex interplay between DP polymorphisms and the multiple Ii regions that cooperatively regulate this association, ultimately controlling the presentation of endogenous antigens on DP molecules. These results may also offer a mechanistic explanation for recent studies identifying the differential effects between DP84Gly and DP84Asp as clinically relevant in human disease.


Assuntos
Apresentação do Antígeno/imunologia , Antígenos de Diferenciação de Linfócitos B/metabolismo , Antígenos HLA-DP/metabolismo , Antígenos de Histocompatibilidade Classe II/metabolismo , Fragmentos de Peptídeos/metabolismo , Linfócitos T/imunologia , Antígenos de Diferenciação de Linfócitos B/genética , Antígenos de Diferenciação de Linfócitos B/imunologia , Antígenos HLA-D/genética , Antígenos HLA-D/imunologia , Antígenos HLA-D/metabolismo , Antígenos HLA-DP/genética , Antígenos HLA-DP/imunologia , Antígenos de Histocompatibilidade Classe II/genética , Antígenos de Histocompatibilidade Classe II/imunologia , Humanos , Ativação Linfocitária , Fragmentos de Peptídeos/imunologia
14.
Front Immunol ; 9: 280, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29520276

RESUMO

T cell alloreactivity is mediated by a self-human leukocyte antigen (HLA)-restricted T cell receptor (TCR) repertoire able to recognize both structurally similar and dissimilar allogeneic HLA molecules (i.e., differing by a single or several amino acids in their peptide-binding groove). We hypothesized that thymic selection on self-HLA molecules could have an indirect impact on the size and diversity of the alloreactive response. To test this possibility, we used TCR Vß immunophenotyping and immunosequencing technology in a model of alloreactivity between self-HLA selected T cells and allogeneic HLA-DPB1 (DPB1) differing from self-DPB1*04:02 by a single (DPB1*02:01) or several (DPB1*09:01) amino acids in the peptide-binding groove. CD4+ T cells from three different self-DPB1*04:01,*04:02 individuals were stimulated with HeLa cells stably transduced with the relevant peptide processing machinery, co-stimulatory molecules, and HLA-DP. Flow cytometric quantification of the DPB1-specific T cell response measured as upregulation of the activation marker CD137 revealed significantly lower levels of alloreactivity against DPB1*02:01 compared with DPB1*09:01 (mean CD4+CD137+ frequency 35.2 ± 9.9 vs. 61.5 ± 7.7%, respectively, p < 0.0001). These quantitative differences were, however, not reflected by differences in the breadth of the alloreactive response at the Vß level, with both alloantigens eliciting specific responses from all TCR-Vß specificities tested by flow cytometry, albeit with higher levels of reactivity from most Vß specificities against DPB1*09:01. In line with these observations, TCRB-CDR3 immunosequencing showed no significant differences in mean clonality of sorted CD137+CD4+ cells alloreactive against DPB1*02:01 or DPB1*09:01 [0.39 (0.36-0.45) and 0.39 (0.30-0.46), respectively], or in the cumulative frequencies of the 10 most frequent responding clones (55-67 and 58-62%, respectively). Most of the clones alloreactive against DPB1*02:01 (68.3%) or DPB1*09:01 (75.3%) were characterized by low-abundance (i.e., they were not appreciable among the pre-culture T cells). Interestingly, however, their cumulative frequency was lower against DPB1*02:01 compared with DPB1*09:01 (mean cumulative frequency 35.3 vs. 50.6%, respectively). Our data show that, despite lower levels of alloreactivity, a similar clonal diversity can be elicited by structurally similar compared with structurally dissimilar HLA-DPB1 alloantigens and demonstrate the power of TCRB immunosequencing in unraveling subtle qualitative changes not appreciable by conventional methods.


Assuntos
Autoantígenos/imunologia , Linfócitos T CD4-Positivos/fisiologia , Antígenos HLA-DP/imunologia , Isoantígenos/imunologia , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Alelos , Seleção Clonal Mediada por Antígeno , Variação Genética , Células HeLa , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Imunofenotipagem
18.
Hum Immunol ; 79(2): 87-88, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29289740

RESUMO

DNA sequence-based typing at the HLA-A, -B, -C, -DPB1, -DQA1, -DQB1, and -DRB1 loci was performed on 714 healthy adult blood bank donors from Colombo, Sri Lanka, to characterize allele frequencies in support of studies on T cell immunity against pathogens, including Dengue virus. Deviations from Hardy Weinberg proportions were not detected at any locus. Several alleles were found in >30% of individuals, including the class II alleles DPB1 * 04:01, DPB1 * 02:01, DQB1 * 06:01 and DRB1 * 07:01, and the class I alleles A * 33:03 and A * 24:02. Genotype data will be available in the Allele Frequencies Net Database.


Assuntos
Antígenos HLA-A/genética , Antígenos HLA-B/genética , Antígenos HLA-C/genética , Antígenos HLA-DP/genética , Antígenos HLA-DQ/genética , Antígenos HLA-DR/genética , Linfócitos T/imunologia , Adulto , Animais , Grupos Étnicos , Feminino , Frequência do Gene , Genótipo , Voluntários Saudáveis , Teste de Histocompatibilidade , Humanos , Masculino , Camundongos , Análise de Sequência de DNA , Sri Lanka
19.
J Immunol Methods ; 454: 80-85, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29154771

RESUMO

T-cell receptor (TCR) redirected T cells are promising tools for adoptive cancer immunotherapy. Since not only CD8 but also CD4 T cells are key players for efficient antitumor responses, the targeted redirection of both subsets with the same antigen-specific TCR comes more and more into focus. Although rapidly evolving technologies enable the reliable genetic re-programming of T cells, the limited availability of TCRs that induce T-cell activation in both T-cell subsets without CD4/CD8 co-receptor contribution hampers the broad application of this approach. We developed a novel stimulation approach, which drives the activation and proliferation of CD4 T-cell populations capable of inducing effector functions in a CD4-independent manner. Naive-enriched CD4 T cells were stimulated against dendritic cells (DC) expressing allogeneic HLA-DP antigens upon RNA transfection and CD4/HLA interactions were blocked by the addition of CD4 binding antibody. Evolving CD4 T-cell populations were specifically activated independent of the CD4 co-signal and induced strong TCR-mediated IFN-γ secretion as well as cytolysis upon recognition of leukemia cells expressing HLA-DP antigen. Our novel stimulation approach may facilitate the generation of CD4 T cells as source for co-receptor independent TCRs for future immunotherapies.


Assuntos
Antígenos CD4/metabolismo , Linfócitos T CD4-Positivos/citologia , Células Dendríticas/imunologia , Imunoterapia Adotiva/métodos , Neoplasias/terapia , Receptores de Antígenos de Linfócitos T/metabolismo , Apresentação do Antígeno , Linfócitos T CD4-Positivos/transplante , Antígenos CD8/metabolismo , Técnicas de Cultura de Células , Proliferação de Células , Células Cultivadas , Reprogramação Celular , Antígenos HLA-DP/genética , Antígenos HLA-DP/imunologia , Humanos , Interferon gama/metabolismo , Isoantígenos/imunologia , Ativação Linfocitária , Neoplasias/imunologia , Transdução de Sinais
20.
J Chem Inf Model ; 58(2): 297-304, 2018 02 26.
Artigo em Inglês | MEDLINE | ID: mdl-28719212

RESUMO

Human leukocyte antigens (HLA) class II proteins are involved in the antigen processing in the antigen presenting cells. They form complexes with antigen peptide fragments. The peptide-HLA protein complexes are presented on the cell surface where they are recognized by helper T cells (Th cells). HLA-DP is one of the three HLA class II loci. The HLA-DP proteins are associated with a significant number of autoimmune diseases, as well as with a susceptibility or resistance to a number of infectious agents. In the present study, we apply proteochemometrics-a method for bioactivity modeling of multiple ligands binding to multiple target proteins-to derive and validate a robust model for peptide binding prediction to the 7 most frequent HLA-DP proteins. The model is able to identify 86% of the binders in the top 10% of the best predicted nonamers generated from one protein.


Assuntos
Antígenos HLA-DP/metabolismo , Modelos Químicos , Peptídeos/metabolismo , Proteômica/métodos , Algoritmos , Aminoácidos/química , Cristalografia por Raios X , Antígenos HLA-DP/química , Humanos , Peptídeos/química , Ligação Proteica , Reprodutibilidade dos Testes
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