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1.
J Chin Med Assoc ; 86(12): 1060-1065, 2023 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-37801591

RESUMO

BACKGROUND: Different human leukocyte antigen (HLA)-DR genotypes have been known to be associated with the risk of development of systemic lupus erythematosus (SLE) in different populations, although Lu et al. have reported previously that no correlation exists between the HLA-DR genotype and disease manifestation in SLE patients in Taiwan. We investigated the effects different HLA-DR genotypes had on SLE incidence in Taiwanese patients as to whether risk alleles were associated with different clinical manifestations, and the effects risk alleles had on the age of disease onset. METHODS: Two hundred thirty-four SLE patients and 346 healthy controls were enrolled. HLA-DR genotyping was performed with the HLA FluoGene DRDQ kit for each subject. Chi-square tests and t tests were performed for statistical analysis. RESULTS: HLA-DR2 was significantly more frequently found in SLE patients than in controls (odds ratio [OR] = 2.05, 95% CI, 1.44-2.92, p < 0.001). Notably, HLA-DR6 appeared to trend toward negative correlation with SLE, whereas HLA-DR8 appeared to trend toward positive correlation. HLA-DR2 patients had an earlier onset of disease as well as a higher prevalence of oral ulcer, avascular necrosis of bone, and renal involvement (lupus nephritis). CONCLUSION: HLA-DR2 was associated with SLE susceptibility in this Taiwanese population as well as lower age of disease onset and more severe clinical manifestations.


Assuntos
Antígeno HLA-DR2 , Lúpus Eritematoso Sistêmico , Humanos , Antígeno HLA-DR2/genética , Taiwan , Predisposição Genética para Doença , Antígenos HLA-DR/genética , Lúpus Eritematoso Sistêmico/genética , Genótipo
2.
Biochem Mol Biol Educ ; 48(2): 175-180, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31794631

RESUMO

In this article, we describe an in-house polymerase chain reaction-sequence specific priming (PCR-SSP) assay designed for undergraduate medical students as part of the experimental pathogen biology and immunology (EPBI) course. It screens human leukocyte antigen (HLA)-DR2 allotype from genomic DNA samples using a rapid and single-tube PCR technique, yielding definitive typing result without conventional post-amplification step like probing or Sanger sequencing. This laboratory exercise offers the undergraduate medical students an opportunity to learn about current molecular biology techniques in HLA genotyping with limited effort and cost, in addition to a better understanding of concepts presented in the classroom lectures. Upon completing this experiment module, the students show statistically significant improvement in several key indexes, such as the knowledge about the mainstream HLA DNA typing techniques, awareness of the relevance of this knowledge for their future scientific research, immunogenetics-related basic laboratory skills they acquire, and interest and desire for mastering this assay (all p < .05). This easy to implement set of experiments is composed of a two-session lab module occupying eight teaching hours, and has been run successfully in our laboratory.


Assuntos
Currículo , DNA/genética , Células Germinativas/metabolismo , Antígeno HLA-DR2/genética , Laboratórios , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , Alelos , Educação de Graduação em Medicina , Humanos , Estudantes de Medicina
3.
Eur J Immunol ; 49(6): 954-965, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30888052

RESUMO

Human immune system (HIS) mouse models provide a robust in vivo platform to study human immunity. Nevertheless, the signals that guide human lymphocyte differentiation in HIS mice remain poorly understood. Here, we have developed a novel Balb/c Rag2-/- Il2rg-/- SirpaNOD (BRGS) HIS mouse model expressing human HLA-A2 and -DR2 transgenes (BRGSA2DR2). When comparing BRGS and BRGSA2DR2 HIS mice engrafted with human CD34+ stem cells, a more rapid emergence of T cells in the circulation of hosts bearing human HLA was shown, which may reflect a more efficient human T-cell development in the mouse thymus. Development of CD4+ and CD8+ T cells was accelerated in BRGSA2DR2 HIS mice and generated more balanced B and T-cell compartments in peripheral lymphoid organs. Both B- and T-cell function appeared enhanced in the presence of human HLA transgenes with higher levels of class switched Ig, increased percentages of polyfunctional T cells and clear evidence for antigen-specific T-cell responses following immunization. Taken together, the presence of human HLA class I and II molecules can improve multiple aspects of human B- and T-cell homeostasis and function in the BRGS-based HIS mouse model.


Assuntos
Modelos Animais de Doenças , Linfopoese/imunologia , Camundongos Transgênicos , Linfócitos T , Animais , Linfócitos B/citologia , Linfócitos B/imunologia , Diferenciação Celular/imunologia , Antígeno HLA-A2/genética , Antígeno HLA-A2/imunologia , Antígeno HLA-DR2/genética , Antígeno HLA-DR2/imunologia , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Linfócitos T/citologia , Linfócitos T/imunologia
4.
Cell Immunol ; 331: 38-48, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29789121

RESUMO

The human autoimmune disease-associated HLA alleles HLA-DR2b (DRB1*1501) and HLA-DR4 (DRB1*0401) are strongly linked to increased susceptibility for multiple sclerosis (MS) and rheumatoid arthritis (RA), respectively. The underlying mechanisms are not fully understood, but these MHC alleles may shape the repertoire of pathogenic T cells via central tolerance. The transcription factor autoimmune regulator (AIRE) promotes central T cell tolerance via ectopic expression of tissue-specific antigens (TSAs). Aire deficiency in humans causes autoimmune polyendocrinopathy syndrome type 1 (APS1), and Aire knockout mice (Aire-/-) develop spontaneous autoimmune pathology characterized by multi-organ lymphocytic infiltrates. Here, we asked whether impaired TSAs gene expression in the absence of Aire promoted spontaneous MS- or RA-like autoimmune pathology in the context of human HLA alleles in HLA-DR2b or HLA-DR4 transgenic (tg) mice. The results show that reduced TSAs gene expression in the thymus of Aire-deficient HLA-DR2b or HLA-DR4 tg mice corresponded to mild spontaneous inflammatory infiltrates in salivary glands, liver, and pancreas. Moreover, Aire-deficiency modestly enhanced experimental autoimmune encephalomyelitis (EAE) in HLA-DR tg mice, but the animals did not show signs of spontaneous neuroinflammation or arthritis. No significant changes were observed in CD4+ T cell numbers, T cell receptor (TCR) distribution, regulatory T cells (Treg), or antigen-induced cytokine production. Abrogating Treg function by treatment with anti-CTLA-4 or anti-CD25 mAb in Aire-deficient HLA-DR tg mice did not trigger EAE or other autoimmune pathology. Our results suggest a redundant role for Aire in maintaining immune tolerance in the context of autoimmune disease-associated human HLA alleles.


Assuntos
Doenças Autoimunes/imunologia , Encefalomielite Autoimune Experimental/imunologia , Antígeno HLA-DR2/imunologia , Antígeno HLA-DR4/imunologia , Fatores de Transcrição/imunologia , Animais , Antígenos/imunologia , Antígenos/metabolismo , Artrite Reumatoide/genética , Artrite Reumatoide/imunologia , Artrite Reumatoide/metabolismo , Doenças Autoimunes/genética , Doenças Autoimunes/metabolismo , Encefalomielite Autoimune Experimental/genética , Encefalomielite Autoimune Experimental/metabolismo , Antígeno HLA-DR2/genética , Antígeno HLA-DR2/metabolismo , Antígeno HLA-DR4/genética , Antígeno HLA-DR4/metabolismo , Humanos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Esclerose Múltipla/genética , Esclerose Múltipla/imunologia , Esclerose Múltipla/metabolismo , Especificidade de Órgãos/imunologia , Linfócitos T/imunologia , Linfócitos T/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteína AIRE
5.
Immunogenetics ; 70(8): 547-551, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29397401

RESUMO

The HLA-DRB1*15:01 allele has a demonstrated risk for the development of multiple sclerosis (MS) in most populations around the world. The single nucleotide polymorphism (SNP) rs3129934 is found in linkage disequilibrium with the risk haplotype formed by the HLA-DRB1*15:01 and HLA-DQB1*06:02 alleles, and it is considered a reliable marker of the presence of this haplotype. Native Americans have a null or low prevalence of MS. In this study, we sought to identify the frequency of rs3129934 in the Wixárika ethnic group as well as in Mestizo (mixed race) patients with MS and in controls from western Mexico. Through real-time polymerase chain reaction (PCR) using TaqMan probes, we analyzed the allele and genotype frequencies of rs3129934 in Mestizo individuals with and without MS and in 73 Wixárika subjects from the state of Jalisco, Mexico. The Wixárika subjects were homozygote for the C allele of rs3129934. The allele and genotype frequency in Mestizos with MS was similar to that of other MS populations with Caucasian ancestry. The absence of the T risk allele rs3129934 (associated with the haplotype HLA-DRB1*15:01, HLA-DQ1*06:02) in this sample of Wixárika subjects is consistent with the unreported MS in this Amerindian group, related to absence of such paramount genetic risk factor.


Assuntos
Antígeno HLA-DR2/genética , Esclerose Múltipla/genética , Adulto , Estudos de Casos e Controles , Etnicidade/genética , Feminino , Frequência do Gene , Predisposição Genética para Doença , Antígenos HLA-DQ/genética , Antígenos HLA-DQ/imunologia , Antígeno HLA-DR2/imunologia , Cadeias HLA-DRB1/genética , Cadeias HLA-DRB1/imunologia , Humanos , Indígenas Norte-Americanos/genética , Desequilíbrio de Ligação , Masculino , México , Esclerose Múltipla/imunologia , Polimorfismo de Nucleotídeo Único , Fatores de Risco
6.
HLA ; 88(1-2): 25-34, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27506953

RESUMO

Asthma is independently associated with HLA-DR3 and increased risks of pneumococcal diseases. We aimed to determine whether HLA-DR polymorphism (HLA-DRB1*03), sensitization to house dust mite (HDM), or their interaction affects humoral immune responses to pneumococcal polysaccharide and protein antigens of intact pneumococci. Induction of serum titers of anti-pneumococcal polysaccharide and anti-surface protein IgM and IgG in response to immunization with intact pneumococci (Pn) serotype 14 was determined using humanized HLA-DR3 and DR2 transgenic mice. Transgenic mice were sensitized by injecting HDM and challenged with intranasal HDM. Mice were subsequently immunized with heat-killed Pn14 at day 24. Serum titers of anti-phosphorylcholine (PC) IgM and IgG, anti-pneumococcal polysaccharide, capsular type 14 (PPS14) IgM and IgG, and anti-pneumococcal surface protein A (PspA) IgG were measured. We included a total of 44 mice (22 DR3 and 22 DR2 mice) and half of mice in each group were sensitized with HDM (i.e. 22 HDM-sensitized and 22 control mice). HDM-sensitized mice, irrespective of HLA-DR polymorphism, had significantly lower humoral immune responses. HLA-DR3 mice, irrespective of HDM sensitization, elicited a significantly lower anti-PC IgG response. In contrast, the anti-PspA IgG response was higher in DR3 relative to DR2 mice. The effect of HDM sensitization on lowering humoral immune responses to Pn14 was observed in DR3 mice regardless of the nature of the antigen, whereas such decreases were observed only for the anti-PPS14 IgG and anti-PC IgM responses in DR2 mice. HDM sensitization lowered humoral immune responses to intact pneumococcus and this effect was significantly modified by the HLA-DR polymorphism.


Assuntos
Anticorpos Antibacterianos/biossíntese , Antígeno HLA-DR2/imunologia , Antígeno HLA-DR3/imunologia , Imunidade Humoral/efeitos dos fármacos , Imunização , Polimorfismo Genético , Streptococcus pneumoniae/imunologia , Animais , Proteínas de Bactérias/administração & dosagem , Proteínas de Bactérias/imunologia , Antígeno HLA-DR2/genética , Antígeno HLA-DR3/genética , Cadeias HLA-DRB1/genética , Cadeias HLA-DRB1/imunologia , Temperatura Alta , Humanos , Imunoglobulina G/biossíntese , Imunoglobulina M/biossíntese , Camundongos , Camundongos Transgênicos , Polissacarídeos Bacterianos/administração & dosagem , Polissacarídeos Bacterianos/imunologia , Pyroglyphidae/imunologia , Streptococcus pneumoniae/química
7.
Prostate ; 74(14): 1423-32, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25111463

RESUMO

INTRODUCTION: Recent studies suggest that the cancer immunotherapy based on the blockade of the CTLA-4-mediated inhibitory pathway is efficacious only in select populations, predominantly for immunogenic tumors or when delivered in combination with modalities that can break immunologic tolerance to tumor antigens. METHODS: We studied the effect of CD25+ cell depletion and CTLA-4 blockade on the growth of Transgenic Mouse Adenocarcinoma of Prostate (TRAMP)-PSA tumor cells in DR2bxPSA F1 mice. In these mice, immunological tolerance to PSA was established in a context of the HLA-DRB1*1501(DR2b) allele. RESULTS: In our model, single administration of anti-CD25 antibody prior to tumor inoculation significantly increased IFN-γ production in response to the CD8 T cell epitope PSA65-73 , and delayed TRAMP-PSA tumor growth compared to mice treated with isotype control antibodies. In contrast, the anti-tumor effect of the anti-CTLA-4 antibody as a monotherapy was marginal. The combinatory treatment with anti-CD25/anti-CTLA-4 antibodies significantly enhanced anti-tumor immunity and caused more profound delay in tumor growth compared to each treatment alone. The proportion of tumor-free animals was higher in the group that received combination treatment (21%) compared to other groups (2-7%). The enhanced anti-tumor immunity in response to the CD25 depletion or CTLA-4 blockade was only seen in the immunogenic TRAMP-PSA tumor model, whereas the effect was completely absent in mice bearing poorly immunogenic TRAMP-C1 tumors. DISCUSSION: Our data suggest that breaking immunological tolerance to "self" antigens is essential for the therapeutic effect of CTLA-4 blockade. Such combinatory treatment may be a promising approach for prostate cancer immunotherapy.


Assuntos
Antígeno CTLA-4/antagonistas & inibidores , Subunidade alfa de Receptor de Interleucina-2/imunologia , Neoplasias da Próstata/imunologia , Neoplasias da Próstata/terapia , Linfócitos T Reguladores/imunologia , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/farmacologia , Linfócitos T CD8-Positivos/imunologia , Antígeno CTLA-4/imunologia , Modelos Animais de Doenças , Antígeno HLA-DR2/genética , Antígeno HLA-DR2/imunologia , Humanos , Tolerância Imunológica , Masculino , Camundongos , Camundongos Transgênicos , Antígeno Prostático Específico/sangue , Antígeno Prostático Específico/imunologia , Distribuição Aleatória
8.
J Am Soc Nephrol ; 25(12): 2859-70, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24925725

RESUMO

Lupus nephritis is a manifestation of SLE resulting from glomerular immune complex deposition and inflammation. Lupus nephritis demonstrates familial aggregation and accounts for significant morbidity and mortality. We completed a meta-analysis of three genome-wide association studies of SLE to identify lupus nephritis-predisposing loci. Through genotyping and imputation, >1.6 million markers were assessed in 2000 unrelated women of European descent with SLE (588 patients with lupus nephritis and 1412 patients with lupus without nephritis). Tests of association were computed using logistic regression adjusting for population substructure. The strongest evidence for association was observed outside the MHC and included markers localized to 4q11-q13 (PDGFRA, GSX2; P=4.5×10(-7)), 16p12 (SLC5A11; P=5.1×10(-7)), 6p22 (ID4; P=7.4×10(-7)), and 8q24.12 (HAS2, SNTB1; P=1.1×10(-6)). Both HLA-DR2 and HLA-DR3, two well established lupus susceptibility loci, showed evidence of association with lupus nephritis (P=0.06 and P=3.7×10(-5), respectively). Within the class I region, rs9263871 (C6orf15-HCG22) had the strongest evidence of association with lupus nephritis independent of HLA-DR2 and HLA-DR3 (P=8.5×10(-6)). Consistent with a functional role in lupus nephritis, intra-renal mRNA levels of PDGFRA and associated pathway members showed significant enrichment in patients with lupus nephritis (n=32) compared with controls (n=15). Results from this large-scale genome-wide investigation of lupus nephritis provide evidence of multiple biologically relevant lupus nephritis susceptibility loci.


Assuntos
Predisposição Genética para Doença , Lúpus Eritematoso Sistêmico/genética , Nefrite Lúpica/genética , Adolescente , Adulto , Idoso , Criança , Feminino , Estudo de Associação Genômica Ampla , Genótipo , Antígeno HLA-DR2/genética , Antígeno HLA-DR3/genética , Humanos , Lúpus Eritematoso Sistêmico/epidemiologia , Lúpus Eritematoso Sistêmico/fisiopatologia , Pessoa de Meia-Idade , Fenótipo , Polimorfismo de Nucleotídeo Único , RNA Mensageiro/metabolismo , População Branca/genética , Adulto Jovem
9.
Int Urol Nephrol ; 45(6): 1647-52, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23673776

RESUMO

PURPOSE: Sensitization to HLA antigens resulting in anti-HLA antibodies (panel reactive antibodies; PRA) is a major problem in chronic kidney disease (CKD) patients awaiting transplantation. Induction of anti-HLA antibodies normally occurs through blood transfusion, pregnancy and prior transplantation. However, some patients develop these antibodies for unknown immunological reasons. It is hypothesized that deviations in immune regulation may account for PRA positivity in these patients. We, therefore, investigated whether a quantitative deficiency in peripheral natural regulatory T cells (CD4(+)CD25(high)Foxp3(+); nTreg) plays a role in this phenomenon. METHODS: Peripheral blood mononuclear cells from 14 patients with positive (Class I and Class II; 10-100 %) and 25 patients with negative PRA, who had not previously been sensitized by blood transfusion, pregnancy and prior transplantation and who had not received any immunomodulatory treatment within the last year, were analyzed for absolute lymphocyte and nTreg numbers through flow cytometry. Samples from 10 healthy people were also used as control. RESULTS: Mean absolute nTreg numbers were determined to be severely reduced in CKD patients (12 ± 9; n = 39) compared with healthy individuals (53 ± 17; n = 10) (p = 0.008). However, absolute nTreg numbers were similar between PRA- (12 ± 11) and PRA+ (11 ± 8) groups. Interestingly, there was a moderate correlation between the nTreg numbers and HLADR2 genotype (n = 9, r = 0.508, p < 0.05). CONCLUSION: This is the first study to demonstrate that the quantitative peripheral nTreg deficiency in CKD patients does not show a causal relationship with the presence of anti-HLA antibodies.


Assuntos
Autoanticorpos/sangue , Contagem de Linfócito CD4 , Antígenos HLA/imunologia , Insuficiência Renal Crônica/imunologia , Linfócitos T Reguladores , Adulto , Estudos de Casos e Controles , Feminino , Genótipo , Antígeno HLA-DR2/genética , Humanos , Transplante de Rim , Masculino , Pessoa de Meia-Idade
10.
PLoS One ; 8(3): e59711, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23555757

RESUMO

Sardinia is a major Island in the Mediterranean with a high incidence of multiple sclerosis, a chronic autoimmune inflammatory disease of the central nervous system. Disease susceptibility in Sardinian population has been associated with five alleles of major histocompatibility complex (MHC) class II DRB1 gene. We performed 120 ns of molecular dynamics simulation on one predisposing and one protective alleles, unbound and in complex with the two relevant peptides: Myelin Basic Protein and Epstein Barr Virus derived peptide. In particular we focused on the MHC peptide binding groove dynamics. The predisposing allele was found to form a stable complex with both the peptides, while the protective allele displayed stability only when bound with myelin peptide. The local flexibility of the MHC was probed dividing the binding groove into four compartments covering the well known peptide anchoring pockets. The predisposing allele in the first half cleft exhibits a narrower and more rigid groove conformation in the presence of myelin peptide. The protective allele shows a similar behavior, while in the second half cleft it displays a narrower and more flexible groove conformation in the presence of viral peptide. We further characterized these dynamical differences by evaluating H-bonds, hydrophobic and stacking interaction networks, finding striking similarities with super-type patterns emerging in other autoimmune diseases. The protective allele shows a defined preferential binding to myelin peptide, as confirmed by binding free energy calculations. All together, we believe the presented molecular analysis could help to design experimental assays, supports the molecular mimicry hypothesis and suggests that propensity to multiple sclerosis in Sardinia could be partly linked to distinct peptide-MHC interaction and binding characteristics of the antigen presentation mechanism.


Assuntos
Predisposição Genética para Doença , Antígeno HLA-DR2/química , Antígeno HLA-DR2/genética , Esclerose Múltipla/genética , Alelos , Herpesvirus Humano 4 , Humanos , Itália , Simulação de Dinâmica Molecular , Esclerose Múltipla/etnologia , Proteína Básica da Mielina/química , Fragmentos de Peptídeos/química , Ligação Proteica , Estrutura Terciária de Proteína
11.
Diabetes Care ; 35(12): 2553-8, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23043167

RESUMO

OBJECTIVE: Type 1 diabetes is a common chronic childhood disease, and the incidence is increasing globally. Childhood infections are considered a potential environmental trigger of type 1 diabetes. Alternatively, improved hygiene and reduced childhood infections could explain the increase in type 1 diabetes in developed countries. The association of reported illnesses during infancy and later development of islet autoimmunity (IA) were examined in the Diabetes Autoimmunity Study in the Young. RESEARCH DESIGN AND METHODS: Complete illness interviews through 9 months of age were collected for 1,729 children-1,174 without a family history of type 1 diabetes and 555 with a first-degree relative with type 1 diabetes. Persistent IA was defined as positive antibodies to insulin, glutamic acid decarboxylase, or tyrosine phosphatase on at least two consecutive study visits. RESULTS: There were 109 children with persistent IA among the 1,729 children with illness records. A greater number of gastrointestinal illnesses were associated with an increased risk of IA, but only among children who were exposed to gluten-containing grains (wheat or barley) either <4 months of age (hazard ratio 1.37 [95% CI 1.22-1.55]; P < 0.0001) or ≥7 months of age (1.12 [1.05-1.19]; P = 0.0005) compared with 4-6 months of age (P for interaction = 0.02). There were no associations of upper respiratory symptoms, respiratory illnesses, or fevers with IA. CONCLUSIONS: Specific pathogens such as enteroviruses or rotavirus may increase the risk of IA in the presence of existing inflammation induced by diet.


Assuntos
Autoimunidade/imunologia , Diabetes Mellitus Tipo 1/epidemiologia , Diabetes Mellitus Tipo 1/imunologia , Autoimunidade/genética , Diabetes Mellitus Tipo 1/genética , Feminino , Gastroenteropatias/complicações , Gastroenteropatias/virologia , Genótipo , Cadeias beta de HLA-DQ/genética , Antígeno HLA-DR2/genética , Cadeias HLA-DRB1/genética , Humanos , Lactente , Recém-Nascido , Masculino , Estudos Prospectivos , Fatores de Risco
12.
Genetika ; 47(6): 847-52, 2011 Jun.
Artigo em Russo | MEDLINE | ID: mdl-21866867

RESUMO

Associations of DR2 specificity of the DRB1gene and single-nucleotide polymorphisms of the tumor necrosis factor gene TNFalpha (-308 G/A), interleukin genes IL-beta (-511 C/T), IL-2 (-475 A/T and -631 G/A), IL-6(-634 C/G), paraoxanase gene PON1 (M55L, Q192R), and the mitochondrial protein transport gene UCP2 (-866 G/A) with the development of multiple sclerosis (MS) were studied in two main ethnic groups of Kazakhstan (Kazakhs and Russians). An association of DR2 specificity of the DRBI gene with MS was found in the combined group of Kazakhs, Russians, and offsprings from mixed marriages. No correlation between DR2 specificity and MS was found in the separately examined groups of Kazakhs and Russians. Statistically significant (p < 0.05) differences between the MS patients and healthy individuals were observed in the distribution of the genotypes at site -634 G/C of the IL-6 gene in the Kazakh group, in the allelic frequencies at site -308 A/G in the promoter region of the TNFalpha gene in the Russian group, and in the frequencies of alleles at the polymorphic Q 192R locus of the PON1 gene in the Kazakh group. No significant differences were revealed in the distribution of the genotypes and in the frequencies of alleles at the polymorphic sites of the genes IL-1beta (-511 C/T), IL-2 (-475 A/T and -631 G/A), PON1 (M55L), and UCP2 (-866 G/A).


Assuntos
Arildialquilfosfatase/genética , Citocinas/genética , Antígeno HLA-DR2/genética , Canais Iônicos/genética , Proteínas Mitocondriais/genética , Esclerose Múltipla/genética , Polimorfismo de Nucleotídeo Único , Adulto , Alelos , Feminino , Frequência do Gene/genética , Marcadores Genéticos/genética , Genótipo , Humanos , Cazaquistão/etnologia , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/etnologia , Proteína Desacopladora 2
13.
Protein Eng Des Sel ; 24(9): 701-9, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21752831

RESUMO

Reliable and robust systems for engineering functional major histocompatibility complex class II (MHCII) proteins have proved elusive. Availability of such systems would enable the engineering of peptide-MHCII (pMHCII) complexes for therapeutic and diagnostic applications. In this paper, we have developed a system based on insect cell surface display that allows functional expression of heterodimeric DR2 molecules with or without a covalently bound human myelin basic protein (MBP) peptide, which is amenable to directed evolution of DR2-MBP variants with improved T cell receptor (TCR)-binding affinity. This study represents the first example of functional display of human pMHCII complexes on insect cell surface. In the process of developing this pMHCII engineering system, we have also explored the potential of using yeast surface display for the same application. Our data suggest that yeast display is a useful system for analysis and engineering of peptide binding of MHCII proteins, but not suitable for directed evolution of pMHC complexes that bind with low affinity to self-reactive TCRs.


Assuntos
Evolução Molecular Direcionada/métodos , Antígeno HLA-DR2/biossíntese , Proteínas de Membrana/biossíntese , Engenharia de Proteínas/métodos , Saccharomyces cerevisiae/metabolismo , Sequência de Aminoácidos , Animais , Baculoviridae/genética , Linhagem Celular , Citometria de Fluxo , Antígeno HLA-DR2/química , Antígeno HLA-DR2/genética , Humanos , Hibridomas , Zíper de Leucina , Proteínas de Membrana/química , Proteínas de Membrana/genética , Camundongos , Dados de Sequência Molecular , Proteína Básica da Mielina/biossíntese , Proteína Básica da Mielina/química , Proteína Básica da Mielina/genética , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Saccharomyces cerevisiae/genética , Alinhamento de Sequência , Spodoptera/citologia , Spodoptera/metabolismo , Spodoptera/virologia , Linfócitos T/metabolismo
14.
Eur J Immunol ; 41(5): 1465-79, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21469129

RESUMO

Antigen-presenting cell-associated four-domain MHC class II (MHC-II) molecules play a central role in activating autoreactive CD4(+) T cells involved in multiple sclerosis (MS) and type 1 diabetes (T1D). In contrast, two-domain MHC-II structures with the same covalently attached self-peptide (recombinant T-cell receptor ligands (RTLs)) can regulate pathogenic CD4(+) T cells and reverse clinical signs of experimental autoimmune diseases. RTL1000, which is composed of the ß1α1 domains of human leukocyte antigen (HLA)-DR2 linked to the encephalitogenic human myelin oligodendrocyte glycoprotein (MOG)-35-55 peptide, was recently shown to be safe and well tolerated in a phase I clinical trial in MS. To evaluate the opposing biological effects of four- versus two-domain MHC-II structures, we screened phage Fab antibodies (Abs) for the neutralizing activity of RTL1000. Five different TCR-like Abs were identified that could distinguish between the two- versus four-domain MHC-peptide complexes while the cognate TCR was unable to make such a distinction. Moreover, Fab detection of native two-domain HLA-DR structures in human plasma implies that there are naturally occurring regulatory MHC-peptide complexes. These results demonstrate for the first time distinct conformational determinants characteristic of activating versus tolerogenic MHC-peptide complexes involved in human autoimmunity.


Assuntos
Células Apresentadoras de Antígenos/imunologia , Linfócitos T CD4-Positivos/imunologia , Antígenos de Histocompatibilidade Classe II/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Animais , Autoimunidade/imunologia , Diabetes Mellitus Tipo 1/imunologia , Encefalomielite Autoimune Experimental/imunologia , Encefalomielite Autoimune Experimental/terapia , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Glicoproteínas , Antígeno HLA-DR2/química , Antígeno HLA-DR2/genética , Antígeno HLA-DR2/imunologia , Humanos , Tolerância Imunológica , Fragmentos Fab das Imunoglobulinas/imunologia , Complexo Principal de Histocompatibilidade/imunologia , Camundongos , Camundongos Transgênicos , Esclerose Múltipla/imunologia , Esclerose Múltipla/terapia , Glicoproteína Mielina-Oligodendrócito , Fragmentos de Peptídeos , Proteínas Recombinantes de Fusão/sangue , Proteínas Recombinantes de Fusão/imunologia , Proteínas Recombinantes/imunologia
15.
Tissue Antigens ; 77(6): 589-92, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21447115

RESUMO

We and others have reported that HLA-DRB1*03 is associated with childhood asthma. To extend this observation and to prove this association, we sensitized and challenged either HLA-DR2 (HLA-DRB1*1502) or HLA-DR3 (HLA-DRB1*0301) transgenic mice with house-dust mite extract. Inflammatory cell counts and cytokine levels in the bronchoalveolar lavage (BAL) fluid between HLA-DR3 and DR2 mice were compared. HLA-DR3 transgenic mice had significantly elevated eosinophil counts, Interleukin-4 and Interleukin-13 levels in the BAL fluid but not interferron gamma-γ. Thus, our study suggests that HLA-DRB1*0301 plays an important role in mounting a Th2-predominant immune response to house dust mite and Th2-type inflammation in the lung.


Assuntos
Antígenos HLA-DR/genética , Antígeno HLA-DR2/genética , Antígeno HLA-DR3/genética , Polimorfismo Genético , Pyroglyphidae/genética , Animais , Líquido da Lavagem Broncoalveolar , Cadeias HLA-DRB1 , Humanos , Sistema Imunitário , Inflamação , Interferon gama/metabolismo , Interleucina-13/metabolismo , Interleucina-4/metabolismo , Camundongos , Camundongos Transgênicos , Células Th2
17.
Nat Immunol ; 12(1): 54-61, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21131964

RESUMO

The mechanisms of HLA-DM-catalyzed peptide exchange remain uncertain. Here we found that all stages of the interaction of HLA-DM with HLA-DR were dependent on the occupancy state of the peptide-binding groove. High-affinity peptides were protected from removal by HLA-DM through two mechanisms: peptide binding induced the dissociation of a long-lived complex of empty HLA-DR and HLA-DM, and high-affinity HLA-DR-peptide complexes bound HLA-DM only very slowly. Nonbinding covalent HLA-DR-peptide complexes were converted into efficient HLA-DM binders after truncation of an N-terminal peptide segment that emptied the P1 pocket and disrupted conserved hydrogen bonds to HLA-DR. HLA-DM thus binds only to HLA-DR conformers in which a critical part of the binding site is already vacant because of spontaneous peptide motion.


Assuntos
Antígenos HLA-D/metabolismo , Antígeno HLA-DR2/metabolismo , Proteínas Mutantes/metabolismo , Fragmentos de Peptídeos/metabolismo , Animais , Apresentação de Antígeno , Células CHO , Catálise , Cricetinae , Cricetulus , Antígenos HLA-D/química , Antígenos HLA-D/genética , Antígeno HLA-DR2/química , Antígeno HLA-DR2/genética , Humanos , Modelos Químicos , Mutagênese Sítio-Dirigida , Proteínas Mutantes/química , Proteínas Mutantes/genética , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/genética , Ligação Proteica , Ressonância de Plasmônio de Superfície , Transgenes/genética
18.
J Neuroimmunol ; 225(1-2): 143-8, 2010 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-20493561

RESUMO

Research on multiple sclerosis (MS) frequently requires typing for allele HLA-DRB1*1501, which the complexities of the HLA system can restrict to specialised histocompatibility laboratories. To overcome this limitation, we have implemented a simple, robust and highly specific method for DRB1*1501 detection. One single-tube polymerase-chain reaction (PCR) per DNA sample allows for detecting DR2 individuals. The spare PCR products of these are then sequenced to identify allele DRB1*1501 by comparison with the official, publicly accessible HLA database. This approach, much simpler than previously available methods, should facilitate research on MS by making accurate identification of DRB1*1501 accessible to neuroscience laboratories.


Assuntos
Testes Genéticos/métodos , Antígenos HLA-DR/genética , Teste de Histocompatibilidade/métodos , Esclerose Múltipla/diagnóstico , Esclerose Múltipla/genética , Alelos , Bases de Dados Genéticas/estatística & dados numéricos , Predisposição Genética para Doença , Antígeno HLA-DR2/genética , Cadeias HLA-DRB1 , Humanos , Reação em Cadeia da Polimerase/métodos , Sensibilidade e Especificidade , Análise de Sequência de DNA/métodos
19.
Respirology ; 15(2): 241-56, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20199642

RESUMO

The importance of host genetic factors in determining susceptibility to tuberculosis (TB) has been studied extensively using various methods, such as case-control, candidate gene and genome-wide linkage studies. Several important candidate genes like human leucocyte antigen/alleles and non-human leucocyte antigen genes, such as cytokines and their receptors, chemokines and their receptors, pattern recognition receptors (including toll-like receptors, mannose binding lectin and the dendritic cell-specific intercellular adhesion molecule-3 grabbing nonintegrin), solute carrier family 11A member 1 (formerly known as natural resistance-associated macrophage protein 1) and purinergic P2X7 receptor gene polymorphisms, have been associated with differential susceptibility to TB in various ethnic populations. This heterogeneity has been explained by host-pathogen and gene-environment interactions and evolutionary selection pressures. Although the achievements of genetics studies might not yet have advanced the prevention and treatment of TB, researchers have begun to widen their scope of investigation to encompass these practical considerations.


Assuntos
Predisposição Genética para Doença/genética , Tuberculose/genética , Quimiocinas/genética , Citocinas/genética , Predisposição Genética para Doença/etnologia , Antígeno HLA-DR2/genética , Humanos , Receptores Purinérgicos P2/genética , Receptores Purinérgicos P2X7 , Receptores Toll-Like/genética , Tuberculose/etnologia
20.
Artigo em Polonês | MEDLINE | ID: mdl-21447263

RESUMO

INTRODUCTION: A clinical criterion of the Wolfram syndrome is the coexistence of diabetes and optic atrophy recognized before the age of 15. Diabetes present in Wolfram syndrome is a result of the selective ß cell loss and failed insulin secretion which is probably associated with non-autoimmune pathogenesis. AIM OF THE STUDY: The aim of the study was an evaluation of HLA subtypes and presence of ß-cell autoantibodies in patients with molecularly confirmed Wolfram syndrome. MATERIAL AND METHODS: 9 patients with Wolfram syndrome aged 10-24 years were examined. We also studied 218 patients with type 1 diabetes as a reference group. A control group of 176 healthy individuals was included in the study. Besides the clinical assessment the HLA typing by PCR-SSO was performed. Islet cell antibodies (ICA), antibodies to glutamic acid decarboxylase (GADA), thyrosine phosphatase antibodies (IA2A) and insulin antibodies (IAA) were also detected. RESULTS: In all nine patients the coexistence of diabetes with optic atrophy was observed and in 8/9 individuals additional symptoms were recognized. In patients with Wolfram syndrome a significantly lower age of diagnosis of diabetes (Me=5.0 years) than in type 1 diabetic children (Me=10.4; p=0.002) was observed. Studies of HLA subtypes demonstrated an increased prevalence of HLA-DQw1, DRB1⋅03 and/or 04 and DR2. A comparison of the frequency of the HLA alleles in patients with Wolfram syndrome with type 1 diabetic children showed a more frequent presence of the DRB1⋅1501 (p=0.03; OR=13.28 (2.44-72.12)) and DQB1⋅06 (p=0.016; OR=10.15 (2.49-41.35)) alleles in patients with Wolfram syndrome. CONCLUSIONS: Polish patients with Wolfram syndrome have a different profile of the HLA antigens with the presence of DR2, DQw1 and DRB3/4 allele and are negative for diabetes-related autoantibodies, which may confirm non-autoimmune ß-cell destruction in this syndrome.


Assuntos
Autoanticorpos/genética , Diabetes Mellitus Tipo 1/imunologia , Genes MHC da Classe II/genética , Síndrome de Wolfram/genética , Síndrome de Wolfram/imunologia , Adolescente , Adulto , Autoanticorpos/imunologia , Criança , Feminino , Antígenos HLA-DQ/genética , Antígenos HLA-DQ/imunologia , Antígenos HLA-DR/genética , Antígenos HLA-DR/imunologia , Antígeno HLA-DR2/genética , Antígeno HLA-DR2/imunologia , Cadeias HLA-DRB3 , Cadeias HLA-DRB4 , Humanos , Masculino , Adulto Jovem
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