Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 201
Filtrar
1.
Int J Biol Macromol ; 267(Pt 2): 131356, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38574928

RESUMO

Cancer cell-killing by CD8+ T cells demands effective tumor antigen presentation by human leukocyte antigen class I (HLA-I) molecules. Screening and designing highly immunogenic neoantigens require quantitative computations to reliably predict HLA-peptide binding affinities. Here, with all-atom molecular dynamics (MD) simulations and free energy perturbation (FEP) methods, we design a collection of antigenic peptide candidates through in silico mutagenesis studies on immunogenic neoantigens, yielding enhanced binding affinities to HLA-B*44:02. In-depth structural dissection shows that introducing positively charged residues such as arginine to position 6 or lysine to position 7 of the candidates triggers conformational shifts in both peptides and the antigen-binding groove of the HLA, following the "induced-fit" mechanism. Enhancement in binding affinities compared to the wild-type was found in three out of five mutated candidates. The HLA pocket, capable of accommodating positively charged residues in positions from 5 to 7, is designated as the "dynamic pocket". Taken together, we showcase an effective structure-based binding affinity optimization framework for antigenic peptides of HLA-B*44:02 and underscore the importance of dynamic nature of the antigen-binding groove in concert with the anchoring motifs. This work provides structural insights for rational design of favorable HLA-peptide bindings and future developments in neoantigen-based therapeutics.


Assuntos
Simulação de Dinâmica Molecular , Peptídeos , Ligação Proteica , Humanos , Peptídeos/química , Peptídeos/imunologia , Antígeno HLA-B44/química , Antígeno HLA-B44/imunologia , Antígeno HLA-B44/genética , Simulação por Computador , Sítios de Ligação , Conformação Proteica
2.
Cytometry A ; 105(5): 376-381, 2024 05.
Artigo em Inglês | MEDLINE | ID: mdl-38379087

RESUMO

Cross reactivities are known for human leukocyte antigen inside HLA-B7 related Cross-Reactive Group (B7CREG). Some CE-IVD flow-cytometry kits use double monoclonal antibodies (mAb) to distinguish HLA-B27 and HLA-B7 but practice reveals more complexes results. This study explores the performances of this test. Analysis of 466 consecutive cases using HLA-B27 IOTest™ kit on a Navios™ cytometer from Beckman-Coulter, partially compared to their genotypes. Expected haplotypes HLA-B27-/HLA-B7- (undoubtedly HLA-B27 negative) and HLA-B27+/HLA-B7- (undoubtedly HLA-B27+) were clearly identified according to the manufacturer's instructions. On the opposite, patients strongly labeled with anti-HLA-B7 showed three different phenotypes regarding anti-HLA-B27 labeling: (1) most of the cases were poorly labeled in accordance with cross reactivity inside B7CREG (HLA-B27-/HLA-B7+ haplotype); (2) rare cases had strong B7 and B27 labeling corresponding to HLA-B27+/HLA-B7+ haplotype; (3) even less cases had strong labeling by anti-HLA-B7 but non for anti-HLA-B27, all expressing HLA-B44 and no B7CREG molecules. Surprisingly, more cases were not labeled with anti-HLA-B7 antibody but partially labeled with anti-HLA-B27 suggesting another cross reactivity out of B7CREG. mAb HLA typing suggests new, cross reactivities of anti-HLA-B27 antibody to more molecules out of B7CREG and of anti-HLA-B7 antibody but not anti-HLA-B27 to HLA-B44 molecule also out of B7CREG. HLA-B27 could surely be excluded in most samples labeled with HLA-B27, below a "grey zone" on intermediate intensity. More comparison is needed in future studies.


Assuntos
Anticorpos Monoclonais , Reações Cruzadas , Citometria de Fluxo , Antígeno HLA-B27 , Antígeno HLA-B44 , Antígeno HLA-B7 , Haplótipos , Humanos , Citometria de Fluxo/métodos , Reações Cruzadas/imunologia , Antígeno HLA-B27/imunologia , Antígeno HLA-B27/genética , Haplótipos/genética , Antígeno HLA-B7/imunologia , Antígeno HLA-B7/genética , Antígeno HLA-B44/imunologia , Antígeno HLA-B44/genética , Anticorpos Monoclonais/imunologia , Antígenos HLA-B/imunologia , Antígenos HLA-B/genética , Genótipo , Imunofenotipagem/métodos
3.
J Immunol ; 211(9): 1298-1307, 2023 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-37737643

RESUMO

The extreme polymorphisms of HLA class I proteins result in structural variations in their peptide binding sites to achieve diversity in Ag presentation. External factors could independently constrict or alter HLA class I peptide repertoires. Such effects of the assembly factor tapasin were assessed for HLA-B*44:05 (Y116) and a close variant, HLA-B*44:02 (D116), which have low and high tapasin dependence, respectively, for their cell surface expression. Analyses of the HLA-B*44:05 peptidomes in the presence and absence of tapasin reveal that peptides with C-terminal tryptophans and higher predicted affinities are preferentially selected by tapasin, coincident with reduced frequencies of peptides with other C-terminal amino acids, including leucine. Comparisons of the HLA-B*44:05 and HLA-B*44:02 peptidomes indicate the expected structure-based alterations near the peptide C termini, but also C-terminal amino acid frequency and predicted affinity changes among the unique and shared peptide groups for B*44:02 and B*44:05. Overall, these findings indicate that the presence of tapasin and the tapasin dependence of assembly alter HLA class I peptide-binding preferences at the peptide C terminus. The particular C-terminal amino acid preferences that are altered by tapasin are expected to be determined by the intrinsic peptide-binding specificities of HLA class I allotypes. Additionally, the findings suggest that tapasin deficiency and reduced tapasin dependence expand the permissive affinities of HLA class I-bound peptides, consistent with prior findings that HLA class I allotypes with low tapasin dependence have increased breadth of CD8+ T cell epitope presentation and are more protective in HIV infections.


Assuntos
Infecções por HIV , Triptofano , Humanos , Antígeno HLA-B44/metabolismo , Triptofano/metabolismo , Peptídeos/metabolismo , Antígenos de Histocompatibilidade Classe I/genética , Antígenos de Histocompatibilidade Classe I/metabolismo , Imunoglobulinas/metabolismo , Ligação Proteica , Antígenos HLA-B/genética , Antígenos HLA-B/metabolismo
4.
Cancer Immunol Immunother ; 72(11): 3559-3566, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37597015

RESUMO

HLA-B alleles are associated with outcomes in various pathologies, including autoimmune diseases and malignancies. The encoded HLA-B proteins are pivotal in antigen presentation to cytotoxic T cells, and some variants containing a Bw4 motif also serve as ligands to the killer immunoglobulin-like receptors (KIR) 3DL1/S1 of NK cells. We investigated the potential impact of HLA-B genotypes on the efficacy of immunotherapy for relapse prevention in acute myeloid leukemia (AML). Seventy-eight non-transplanted AML patients receiving HDC/IL-2 in the post-consolidation phase were genotyped for HLA-B and KIR genes. HLA-B*44 heralded impaired LFS (leukemia-free survival) and overall survival (OS), but the negative association with outcome was not shared across alleles of the HLA-B44 supertype. Notably, HLA-B*44 is one of few HLA-B44 supertype alleles containing a Bw4 motif with a threonine at position 80, which typically results in weak binding to the inhibitory NK receptor, KIR3DL1. Accordingly, a strong interaction between KIR3DL1 and Bw4 was associated with superior LFS and OS (p = 0.014 and p = 0.027, respectively). KIR3DL1+ NK cells from 80 T-Bw4 donors showed significantly lower degranulation responses and cytokine responses than NK cells from 80I-Bw4 donors, suggesting impaired KIR3DL1-mediated education in 80 T-Bw4 subjects. We propose that presence of a strong KIR3DL1+-Bw4 interaction improves NK cell education and thus is advantageous in AML patients receiving HDC/IL-2 immunotherapy for relapse prevention.


Assuntos
Interleucina-2 , Leucemia Mieloide Aguda , Humanos , Antígenos HLA-B/genética , Antígeno HLA-B44 , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/terapia , Recidiva , Imunoterapia
5.
J Biomed Sci ; 29(1): 80, 2022 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-36224625

RESUMO

BACKGROUND: Human Papillomavirus type 18 (HPV18) is a high-risk HPV that is commonly associated with cervical cancer. HPV18 oncogenes E6 and E7 are associated with the malignant transformation of cells, thus the identification of human leukocyte antigen (HLA)-restricted E6/E7 peptide-specific CD8 + T cell epitopes and the creation of a HPV18 E6/E7 expressing cervicovaginal tumor in HLA-A2 transgenic mice will be significant for vaccine development. METHODS: In the below study, we characterized various human HLA class I-restricted HPV18 E6 and E7-specific CD8 + T cells mediated immune responses in HLA class I transgenic mice using DNA vaccines encoding HPV18E6 and HPV18E7. We then confirmed HLA-restricted E6/E7 specific CD8 + T cell epitopes using splenocytes from vaccinated mice stimulated with HPV18E6/E7 peptides. Furthermore, we used oncogenic DNA plasmids encoding HPV18E7E6(delD70), luciferase, cMyc, and AKT to create a spontaneous cervicovaginal carcinoma model in HLA-A2 transgenic mice. RESULTS: Therapeutic HPV18 E7 DNA vaccination did not elicit any significant CD8 + T cell response in HLA-A1, HLA-24, HLA-B7, HLA-B44 transgenic or wild type C57BL/6 mice, but it did generate a strong HLA-A2 and HLA-A11 restricted HPV18E7-specific CD8 + T cell immune response. We found that a single deletion of aspartic acid (D) at location 70 in HPV18E6 DNA abolishes the presentation of HPV18 E6 peptide (aa67-75) by murine MHC class I. We found that the DNA vaccine with this mutant HPV18 E6 generated E6-specific CD8 + T cells in HLA-A2. HLA-A11, HLA-A24 and HLA-b40 transgenic mice. Of note, HLA-A2 restricted, HPV18 E7 peptide (aa7-15)- and HPV18 E6 peptide (aa97-105)-specific epitopes are endogenously processed by HPV18 positive Hela-AAD (HLA-A*0201/Dd) cells. Finally, we found that injection of DNA plasmids encoding HPV18E7E6(delD70), AKT, cMyc, and SB100 can result in the development of adenosquamous carcinoma in the cervicovaginal tract of HLA-A2 transgenic mice. CONCLUSIONS: We characterized various human HLA class I-restricted HPV18 E6/E7 peptide specific CD8 + T cell epitopes in human HLA class I transgenic mice. We demonstrated that HPV18 positive Hela cells expressing chimeric HLA-A2 (AAD) do present both HLA-A2-restricted HPV18 E7 (aa7-15)- and HPV18 E6 (aa97-105)-specific CD8 + T cell epitopes. A mutant HPV18E6 that had a single deletion at location 70 obliterates the E6 presentation by murine MHC class I and remains oncogenic. The identification of these human MHC restricted HPV antigen specific epitopes as well as the HPV18E6/E7 expressing adenosquamous cell carcinoma model may have significant future translational potential.


Assuntos
Carcinoma Adenoescamoso , Proteínas Oncogênicas Virais , Infecções por Papillomavirus , Vacinas de DNA , Animais , Ácido Aspártico , Linfócitos T CD8-Positivos , Carcinoma Adenoescamoso/complicações , Epitopos de Linfócito T/genética , Feminino , Antígenos HLA-A , Antígeno HLA-A1 , Antígeno HLA-A11 , Antígeno HLA-A2/genética , Antígeno HLA-A24 , Antígeno HLA-B40 , Antígeno HLA-B44 , Antígeno HLA-B7 , Células HeLa , Papillomavirus Humano 18 , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Proteínas Oncogênicas Virais/genética , Infecções por Papillomavirus/complicações , Peptídeos , Proteínas Proto-Oncogênicas c-akt , Linfócitos T Citotóxicos , Vacinas de DNA/genética
6.
Front Immunol ; 13: 951422, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36275748

RESUMO

Relapsed/refractory ovarian cancer, especially platinum resistance recurrence, remains a major therapeutic challenge. Here, we present the case of a patient with recurrent ovarian clear cell carcinoma (OCCC) who failed to respond to multiline chemotherapy and target therapy but achieved an immune complete response (iCR) with programmed cell death 1 (PD-1) inhibitor treatment. The overall survival (OS) was 59 months, and the recurrence-free survival (RFS) was 34 months after immunotherapy, which was counting. Meantime, molecular testing results revealed that traditional biomarkers for immunotherapy, including PD-L1 expression, microsatellite instability (MSI), and tumor mutational burden (TMB), were negative. HLA-B44 (B*18:01) supertype was confirmed by sequence-based HLA typing. This case raises the possibility that ovarian cancer patients with multidrug resistance may still benefit from PD-1 inhibitor therapy, even if PD-L1 pathology is negative.


Assuntos
Antineoplásicos Imunológicos , Neoplasias Ovarianas , Humanos , Feminino , Antígeno B7-H1/metabolismo , Receptor de Morte Celular Programada 1/metabolismo , Antígeno HLA-B44 , Antineoplásicos Imunológicos/uso terapêutico , Inibidores de Checkpoint Imunológico , Platina , Recidiva Local de Neoplasia/tratamento farmacológico , Carcinoma Epitelial do Ovário , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/genética , Apoptose
7.
J Infect Dis ; 222(5): 840-846, 2020 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-32737971

RESUMO

BACKGROUND: Major histocompatibility complex class I chain-related (MIC) A and B (MICA and MICB) are polymorphic stress molecules recognized by natural killer cells. This study was performed to analyze MIC gene profiles in hospitalized Thai children with acute dengue illness. METHODS: MIC allele profiles were determined in a discovery cohort of patients with dengue fever or dengue hemorrhagic fever (DHF) (n = 166) and controls (n = 149). A replication cohort of patients with dengue (n = 222) was used to confirm specific MICB associations with disease. RESULTS: MICA*045 and MICB*004 associated with susceptibility to DHF in secondary dengue virus (DENV) infections (odds ratio [OR], 3.22; [95% confidence interval (CI), 1.18-8.84] and 1.99 [1.07-2.13], respectively), and MICB*002 with protection from DHF in secondary DENV infections (OR, 0.41; 95% CI, .21-.68). The protective effect of MICB*002 against secondary DHF was confirmed in the replication cohort (OR, 0.43; 95% CI, .22-.82) and was stronger when MICB*002 is present in individuals also carrying HLA-B*18, B*40, and B*44 alleles which form the B44 supertype of functionally related alleles (0.29, 95% CI, .14-.60). CONCLUSIONS: Given that MICB*002 is a low expresser of soluble proteins, these data indicate that surface expression of MICB*002 with B44 supertype alleles on DENV-infected cells confer a protective advantage in controlling DENV infection using natural killer cells.


Assuntos
Povo Asiático/genética , Genes MHC Classe I/genética , Predisposição Genética para Doença , Antígenos de Histocompatibilidade Classe I/genética , Dengue Grave/genética , Adolescente , Alelos , Criança , Pré-Escolar , Antígeno HLA-B18/genética , Antígeno HLA-B40/genética , Antígeno HLA-B44/genética , Haplótipos , Humanos , Desequilíbrio de Ligação/genética , Fatores de Proteção , Tailândia/etnologia
8.
Int J Mol Sci ; 21(15)2020 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-32717807

RESUMO

The spread of COVID-19 is showing huge, unexplained, differences between northern and southern Italy. We hypothesized that the regional prevalence of specific class I human leukocyte antigen (HLA) alleles, which shape the anti-viral immune response, might partly underlie these differences. Through an ecological approach, we analyzed whether a set of HLA alleles (A, B, C), known to be involved in the immune response against infections, correlates with COVID-19 incidence. COVID-19 data were provided by the National Civil Protection Department, whereas HLA allele prevalence was retrieved through the Italian Bone-Marrow Donors Registry. Among all the alleles, HLA-A*25, B*08, B*44, B*15:01, B*51, C*01, and C*03 showed a positive log-linear correlation with COVID-19 incidence rate fixed on 9 April 2020 in proximity of the national outbreak peak (Pearson's coefficients between 0.50 and 0.70, p-value < 0.0001), whereas HLA-B*14, B*18, and B*49 showed an inverse log-linear correlation (Pearson's coefficients between -0.47 and -0.59, p-value < 0.0001). When alleles were examined simultaneously using a multiple regression model to control for confounding factors, HLA-B*44 and C*01 were still positively and independently associated with COVID-19: a growth rate of 16% (95%CI: 0.1-35%) per 1% point increase in B*44 prevalence; and of 19% (95%CI: 1-41%) per 1% point increase in C*01 prevalence. Our epidemiologic analysis, despite the limits of the ecological approach, is strongly suggestive of a permissive role of HLA-C*01 and B*44 towards SARS-CoV-2 infection, which warrants further investigation in case-control studies. This study opens a new potential avenue for the identification of sub-populations at risk, which could provide Health Services with a tool to define more targeted clinical management strategies and priorities in vaccination campaigns.


Assuntos
Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/genética , Antígeno HLA-B44/genética , Antígenos HLA-C/genética , Pneumonia Viral/epidemiologia , Pneumonia Viral/genética , COVID-19 , Infecções por Coronavirus/imunologia , Frequência do Gene , Humanos , Itália/epidemiologia , Pandemias , Pneumonia Viral/imunologia , Prevalência , Sistema de Registros , Análise de Regressão
9.
Nat Cancer ; 1(12): 1167-1175, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-35121931

RESUMO

Human leukocyte antigen (HLA)-B has been recognized as a major determinant of discrepancies in disease outcomes, and recent evidence indicates a role in immune checkpoint blockade (ICB) efficacy. The B44 supertype, which features an electropositive binding pocket that preferentially displays peptides with negatively charged amino acid anchors, is associated with improved survival in ICB-treated melanoma. Yet this effect was not seen in ICB-treated non-small-cell lung cancer (NSCLC). Here we show that mutations leading to glutamic acid substitutions occur more often in melanoma than NSCLC based on mutational landscape. We additionally show stratifying B44 based on the presence of somatic mutations that lead to negatively charged glutamic acid anchors identifies patients with NSCLC with an ICB benefit similar to that seen in melanoma. We anticipate these findings could improve assessment of HLA-related outcomes and prediction of ICB benefit in those with B44, representing approximately half of the world's population.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Melanoma , Carcinoma Pulmonar de Células não Pequenas/genética , Ácido Glutâmico/genética , Antígenos HLA-B/genética , Antígeno HLA-B44/genética , Humanos , Imunoterapia , Neoplasias Pulmonares/genética , Melanoma/genética , Mutação
10.
Comput Biol Chem ; 84: 107195, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31877499

RESUMO

Major Histocompatibility Complex (MHC) is a cell surface glycoprotein that binds to foreign antigens and presents them to T lymphocyte cells on the surface of Antigen Presenting Cells (APCs) for appropriate immune recognition. Recently, studies focusing on peptide-based vaccine design have allowed a better understanding of peptide immunogenicity mechanisms, which is defined as the ability of a peptide to stimulate CTL-mediated immune response. Peptide immunogenicity is also known to be related to the stability of peptide-loaded MHC (pMHC) complex. In this study, ENCoM server was used for structure-based estimation of the impact of single point mutations on pMHC complex stabilities. For this purpose, two human MHC molecules from the HLA-B*27 group (HLA-B*27:05 and HLA-B*27:09) in complex with four different peptides (GRFAAAIAK, RRKWRRWHL, RRRWRRLTV and IRAAPPPLF) and three HLA-B*44 molecules (HLA-B*44:02, HLA-B*44:03 and HLA-B*44:05) in complex with two different peptides (EEYLQAFTY and EEYLKAWTF) were analyzed. We found that the stability of pMHC complexes is dependent on both peptide sequence and MHC allele. Furthermore, we demonstrate that allele-specific peptide-binding preferences can be accurately revealed using structure-based computational methods predicting the effect of mutations on protein stability.


Assuntos
Antígeno HLA-B27/metabolismo , Antígeno HLA-B44/metabolismo , Peptídeos/metabolismo , Alelos , Bases de Dados de Proteínas/estatística & dados numéricos , Antígeno HLA-B27/química , Antígeno HLA-B27/genética , Antígeno HLA-B44/química , Antígeno HLA-B44/genética , Humanos , Mutação , Ligação Proteica , Estabilidade Proteica
11.
Can J Neurol Sci ; 47(2): 189-196, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31787121

RESUMO

OBJECTIVE: In a previous pilot monocentric study, we investigated the relation between human leukocyte antigen (HLA) genotype and multiple sclerosis (MS) disease progression over 2 years. HLA-A*02 allele was correlated with better outcomes, whereas HLA-B*07 and HLA-B*44 were correlated with worse outcomes. The objective of this extension study was to further investigate the possible association of HLA genotype with disease status and progression in MS as measured by sensitive and complex clinical and imaging parameters. METHODS: Hundred and forty-six MS patients underwent HLA typing. Over a 4-year period of follow-up, we performed three clinical and magnetic resonance imaging (MRI) assessments per patient, which respectively included Expanded Disability Status Scale, Multiple Sclerosis Severity Scale, Timed-25-Foot-Walk, 9-Hole Peg Test, Symbol Digit Modalities Test, Brief Visual Memory Test, California Verbal Learning Test-II, and whole-brain atrophy, fluid-attenuated inversion recovery (FLAIR) lesion volume change and number of new FLAIR lesions using icobrain. We then compared the clinical and MRI outcomes between predefined HLA patient groups. RESULTS: Results of this larger study with a longer follow-up are in line with what we have previously shown. HLA-A*02 allele is associated with potentially better MS outcomes, whereas HLA-B*07, HLA-B*44, HLA-B*08, and HLA-DQB1*06 with a potential negative effect. Results for HLA-DRB1*15 are inconclusive. CONCLUSION: In the era of MS treatment abundance, HLA genotype might serve as an early biomarker for MS outcomes to inform individualized treatment decisions.


Assuntos
Cadeias beta de HLA-DQ/genética , Antígenos de Histocompatibilidade Classe I/genética , Esclerose Múltipla Crônica Progressiva/genética , Esclerose Múltipla Recidivante-Remitente/genética , Adolescente , Adulto , Idoso , Progressão da Doença , Feminino , Genótipo , Antígeno HLA-A2/genética , Antígeno HLA-B44/genética , Antígeno HLA-B7/genética , Antígeno HLA-B8/genética , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla Crônica Progressiva/diagnóstico por imagem , Esclerose Múltipla Crônica Progressiva/tratamento farmacológico , Esclerose Múltipla Crônica Progressiva/fisiopatologia , Esclerose Múltipla Recidivante-Remitente/diagnóstico por imagem , Esclerose Múltipla Recidivante-Remitente/tratamento farmacológico , Esclerose Múltipla Recidivante-Remitente/fisiopatologia , Prognóstico , Adulto Jovem
12.
BMC Pediatr ; 19(1): 249, 2019 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-31337377

RESUMO

BACKGROUND: Human leukocyte antigen (HLA) molecules play a key role in the cellular immune system. They may be determinants of mother-to-child transmission which is the driving force in pediatric HIV infection. We intended to look at the impact of the distribution of these polymorphic HLA genes in the mother-to-child transmission (MTCT) of HIV in Cameroon. METHODS: A total of 156 mother-baby pairs were enrolled in three hospitals of Yaounde, capital of Cameroon. After the extraction of the DNA from blood samples using the Qiagen Kit as per manufacturer' instructions, the polymorphism of the HLA class 1 ABC was determined using the PCR- sequence specific primers assay. RESULTS: The distribution of HLA class 1 revealed that none of the allele studied was associated with transmitters or non-transmitters, so was not implicated in transmission. The regression analysis showed that HLA A*32 [OR 0.062 (CI; 0.0075 to 0.51)] is associated with HIV acquisition while HLA B*44 [OR 0.47 (CI; 0.21 to 1.14)] and HLA B*53 [OR; 0.14 (CI; 0.018 to 1.22)] were implicated in reducing the acquisition of HIV by infants. The homozygosity of locus C [OR 6.99 (CI; 1.81 to 26.88), p = 0.0027] was found as a risk factor for the acquisition, while the A*32-B*44 haplotype [OR 10.1 (CI 1.17 to 87.87), p = 0.03] was a risk factor for the transmission. CONCLUSION: This study has found that HLA A*32, B*44 and B*53 have an impact in MTCT outcomes. The homozygosity of locus C and the A*32-B*44 haplotype were risk factors for acquisition and transmission respectively.


Assuntos
Infecções por HIV/transmissão , Antígenos HLA-A/genética , Homozigoto , Transmissão Vertical de Doenças Infecciosas , Adulto , Feminino , Antígenos HLA , Antígeno HLA-B44 , Haplótipos , Humanos , Lactente
13.
HLA ; 94(4): 347-359, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31353832

RESUMO

Allele-level HLA compatibility in cord blood transplantation has been associated with better transplant outcomes and is recommended as a selection criterion. It is also a crucial aspect for other therapeutic applications involving cord blood-derived cells. Determination of high-resolution HLA frequencies is an important step towards improving the quality of cord blood banks. We analyzed HLA-A, -B, -C, -DRB1, and -DQB1 allele frequencies in 5458 high-quality cord blood units from the Barcelona Cord Blood Bank and identified 275 class I and 121 class II HLA alleles. A*02:01, B*44:03, C*07:01, DRB1*07:01 and DQB1*03:01 were the most frequent alleles at each locus. We detected 26 novel alleles and were able to determine the presence or absence of some null alleles, including C*04:09N, in a large number of units. We also analyzed maternal HLA typing information for 1877 units to determine real haplotype frequencies and linkage disequilibrium. A*29:02-B*44:03-C*16:01-DRB1*07:01-DQB1*02:02 was the most frequent HLA haplotype and the DRB1-DQB1 gene pair contained the two-locus haplotypes with the strongest linkage disequilibrium values. Four of the 11 unique haplotypes identified in the HLA-homozygous cord blood units were the top-ranking haplotypes identified and were present in 18% of the cohort. This is the first study to report on HLA allele and haplotype frequencies for umbilical cord blood units from the Barcelona Cord Blood Bank and the largest study to date involving two fields of HLA resolution typing of Spanish registry data.


Assuntos
Sangue Fetal/imunologia , Antígenos HLA-A/genética , Antígenos HLA-B/genética , Antígenos HLA-C/genética , Cadeias beta de HLA-DQ/genética , Cadeias HLA-DRB1/genética , Regiões 3' não Traduzidas , Alelos , Bancos de Sangue , Feminino , Frequência do Gene , Genótipo , Antígeno HLA-A2/genética , Antígeno HLA-B44/genética , Haplótipos , Homozigoto , Humanos , Desequilíbrio de Ligação , Masculino , Mães , Polimorfismo de Nucleotídeo Único , Gravidez
15.
Front Immunol ; 9: 2539, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30487790

RESUMO

Lack of disease during chronic human cytomegalovirus (CMV) infection depends on the maintenance of a high-frequency CMV-specific T cell response. The composition of the T cell receptor (TCR) repertoire underlying this response remains poorly characterised, especially within African populations in which CMV is endemic from infancy. Here we focus on the immunodominant CD8+ T cell response to the immediate-early 2 (IE-2)-derived epitope NEGVKAAW (NW8) restricted by HLA-B*44:03, a highly prevalent response in African populations, which in some subjects represents >10% of the circulating CD8+ T cells. Using pMHC multimer staining and sorting of NW8-specific T cells, the TCR repertoire raised against NW8 was characterised here using high-throughput sequencing in 20 HLA-B*44:03 subjects. We found that the CD8+ T cell repertoire raised in response to NW8 was highly skewed and featured preferential use of a restricted set of V and J gene segments. Furthermore, as often seen in immunity against ancient viruses like CMV and Epstein-Barr virus (EBV), the response was strongly dominated by identical TCR sequences shared by multiple individuals, or "public" TCRs. Finally, we describe a pair "superdominant" TCR clonotypes, which were germline or nearly germline-encoded and produced at remarkably high frequencies in certain individuals, with a single CMV-specific clonotype representing up to 17% of all CD8+ T cells. Given the magnitude of the NW8 response, we propose that this major skewing of CMV-specific immunity leads to massive perturbations in the overall TCR repertoire in HLA-B*44:03 individuals.


Assuntos
População Negra , Linfócitos T CD8-Positivos/fisiologia , Infecções por Citomegalovirus/imunologia , Citomegalovirus/fisiologia , Receptores de Antígenos de Linfócitos T/genética , Adulto , Epitopos de Linfócito T/imunologia , Citometria de Fluxo , Antígeno HLA-B44/metabolismo , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Proteínas Imediatamente Precoces/genética , Proteínas Imediatamente Precoces/imunologia , Imunidade Celular , Epitopos Imunodominantes/imunologia , Masculino , Peptídeos/genética , Peptídeos/imunologia , África do Sul , Transativadores/genética , Transativadores/imunologia , Adulto Jovem
16.
Sci Rep ; 8(1): 659, 2018 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-29330418

RESUMO

IFNL3 is the strongest predictor of spontaneous resolution (SR) of hepatitis C virus (HCV), however, consideration of IFNL3 genotype alone is of limited clinical value for the prediction of SR or chronic HCV infection. The objective of this study was to analyze the impact of HLA-B, HLA-C and KIRs on SR, as well as their additive effects on the predictive value of the IFNL3 genotype. We conducted a retrospective study of HIV patients that included both SR and chronic HCV patients. In our study, 61.6% of patients with IFNL3 CC achieved SR, and 81.5% with non-CC genotypes did not achieve SR. HLA-B*44, HLA-C*12, and KIR3DS1 were identified as predictive factors for SR, with percentages of 77.4%, 85.7% and 86.2%, respectively, for patients who did not experience SR. The presence of at least one of these three markers, defined as a genetically unfavorable profile (GUP), combined with the IFNL3 non-CC genotype showed a value of 100% for non-SR. The absence of the three markers, defined as a genetically favorable profile (GFP), in addition to the IFNL3 CC genotype showed a percentage of 74.1% for SR. The combination of these markers in addition to the IFNL3 genotype improves the predictive value of IFNL3 for SR of acute HCV infection in HIV patients, which would be clinically valuable.


Assuntos
Infecções por HIV/complicações , Antígeno HLA-B44/genética , Antígenos HLA-C/genética , Hepatite C Crônica/virologia , Interleucinas/genética , Receptores KIR3DS1/genética , Feminino , Marcadores Genéticos , Infecções por HIV/genética , Infecções por HIV/virologia , Hepacivirus/fisiologia , Hepatite C Crônica/genética , Humanos , Interferons , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Retrospectivos , Carga Viral
17.
HLA ; 90(2): 125-127, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28371263

RESUMO

Confirmed the full-length sequence of HLA-B*44:03:02 by cloning and sequencing in a Chinese donor.


Assuntos
Clonagem Molecular , Antígeno HLA-B44/genética , Análise de Sequência de DNA , Humanos
18.
Clin Exp Rheumatol ; 35 Suppl 105(3): 68-73, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28422000

RESUMO

OBJECTIVES: We sought to determine the prevalence and clinical and laboratory associations of fibromyalgia in adults with primary immunodeficiency (immunoglobulin (Ig) G subclass deficiency (IgGSD) and common variable immunodeficiency (CVID). METHODS: We performed a retrospective analysis of these observations in 300 non-Hispanic white adult index patients with recurrent/severe respiratory tract infections and IgGSD or CVID: age; sex; IgGSD; fibromyalgia; chronic fatigue; autoimmune conditions (ACs); interstitial cystitis (IC); diabetes; body mass index; serum Ig isotypes; blood lymphocytes and subsets; and human leukocyte antigen (HLA)-A and -B types and haplotypes. We performed univariate comparisons, logistic multivariable regressions, and an analysis of covariance. RESULTS: Mean age was 49 ± 12 (standard deviation) y. There were 246 women (82.0%). IgGSD was diagnosed in 276 patients (92.0%). Fifty-six patients had fibromyalgia (18.7%; female:male 13:1). Other characteristics included: chronic fatigue, 63.0%; aggregate ACs, 35.3%; Sjögren's syndrome, 8.0%; IC, 3.0%; diabetes, 10.3%; and HLA-A*29, B*44 positivity, 9.7%. Prevalences of female sex; chronic fatigue; IC; and HLA-A*29, B*44 positivity were greater in patients with fibromyalgia. Logistic regression on fibromyalgia revealed three positive associations: chronic fatigue (p=0.0149; odds ratio 2.6 [95% confidence interval 1.2, 5.6]); Sjögren's syndrome (p=0.0004; 5.2 [2.1, 13.2]); and IC (p=0.0232; 5.7 [1.3, 25.7]). In an analysis of covariance, there were significant interactions of chronic fatigue, Sjögren's syndrome, and interstitial cystitis on fibromyalgia. CONCLUSIONS: Fibromyalgia is common in non-Hispanic white adult index patients with primary immunodeficiency, especially women. Chronic fatigue, Sjögren's syndrome, and IC are significantly associated with fibromyalgia after adjustment for other independent variables.


Assuntos
Imunodeficiência de Variável Comum/epidemiologia , Fibromialgia/epidemiologia , Deficiência de IgG/epidemiologia , Síndrome de Sjogren/epidemiologia , Adulto , Doenças Autoimunes/epidemiologia , Imunodeficiência de Variável Comum/genética , Cistite Intersticial/epidemiologia , Síndrome de Fadiga Crônica/epidemiologia , Feminino , Fibromialgia/genética , Antígenos HLA-A/genética , Antígeno HLA-B44/genética , Haplótipos , Humanos , Deficiência de IgG/genética , Síndromes de Imunodeficiência/epidemiologia , Síndromes de Imunodeficiência/genética , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Prevalência , Estudos Retrospectivos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...