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1.
Mol Neurobiol ; 61(11): 9539-9547, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38652350

RESUMO

Genome-wide association studies (GWAS) have provided strong evidence that early- and late-onset MG have different genetic backgrounds. Recent in silico analysis based on GWAS results revealed rs231735 and rs231770 variants within CTLA-4 locus as possible MG causative genetic factors. We aimed to explore the association of rs231735 and rs231770 with MG in a representative cohort of Serbian patients. We conducted an age-, sex-, and ethnicity-matched case-control study. Using TaqMan allele discrimination assays, the frequency of rs231735 and rs231770 genetic variants was examined in 447 AChR-MG patients and 447 matched controls. There was no significant association of rs231735 and rs231770 with the entire MG cohort (P > 0.05). Nevertheless, when stratifying patients into early-onset (n = 183) and late-onset MG (n = 264), we found early-onset patients had a significantly lower frequency of the rs231735 allele T compared to controls (OR = 0.734, 95% CI = 0.575-0.938, p10e6 permutation < 0.05), and rs231735 genotype TT and rs231770 genotype TT had a protective effect on early-onset MG (OR = 0.548, 95% CI = 0.339-0.888, and OR = 0.563, 95% CI = 0.314-1.011, p10e6 permutation < 0.05). Consequently, we found that individuals with the rs231735-rs231770 haplotype GC had a higher risk for developing early-onset MG (OR = 1.360, P = 0.027, p10e6 permutation < 0.05). Our results suggest that CTLA-4 rs231735 and rs231770 may be risk factors only for patients with early-onset MG in Serbian population.


Assuntos
Idade de Início , Antígeno CTLA-4 , Predisposição Genética para Doença , Miastenia Gravis , Polimorfismo de Nucleotídeo Único , Receptores Colinérgicos , Humanos , Miastenia Gravis/genética , Antígeno CTLA-4/genética , Masculino , Feminino , Sérvia/epidemiologia , Adulto , Polimorfismo de Nucleotídeo Único/genética , Estudos de Casos e Controles , Receptores Colinérgicos/genética , Pessoa de Meia-Idade , Frequência do Gene/genética , Loci Gênicos , Adulto Jovem , Idoso
2.
Front Immunol ; 14: 1155778, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37441075

RESUMO

Antibody-based cancer immunotherapy has become a powerful asset in the arsenal against malignancies. In this regard, bispecific antibodies (BsAbs) are a ground-breaking novel approach in the therapy of cancers. Recently, BsAbs have represented a significant advancement in improving clinical outcomes. BsAbs are designed to target two different antigens specifically. Over a hundred various BsAb forms currently exist, and more are constantly being manufactured. An antagonistic regulator of T cell activation is cytotoxic T lymphocyte-associated protein 4 (CTLA-4) or CD152, a second counter-receptor for the B7 family of co-stimulatory molecules was introduced in 1996 by Professor James P. Allison and colleagues. Contrary to the explosive success of dual immune checkpoint blockade for treating cancers, a major hurdle still yet persist is that immune-related adverse events (irAEs) observed by combining immune checkpoint inhibitors (ICIs) or monoclonal antibodies such as ipilimumab (anti-CTLA-4) and nivolumab (anti-PD-1). A promising strategy to overcome this hurdle is using BsAbs. This article will summarize BsAbs targeting CTLA-4, their applications in cancer immunotherapy, and relevant clinical trial advances. We will also discuss the pre-clinical rationale for using these BsAbs, and provide the current landscape of the field.


Assuntos
Anticorpos Biespecíficos , Neoplasias , Humanos , Anticorpos Biespecíficos/uso terapêutico , Ipilimumab/uso terapêutico , Anticorpos Monoclonais/uso terapêutico , Imunoterapia/efeitos adversos
3.
Front Immunol ; 13: 885005, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35784316

RESUMO

The moderate activation of T cells in mammals requires the costimulatory molecules, CD80 and CD86, on antigen-presenting cells to interact with their respective T cell receptors, CD28 and CD152 (CTLA-4), to promote costimulatory signals. In contrast, teleost fish (except salmonids) only possess CD80/86 as their sole primordial costimulatory molecule. However, the mechanism, which underlies the interaction between CD80/86 and its receptors CD28 and CD152 still requires elucidation. In this study, we cloned and identified the CD80/86, CD28, and CD152 genes of the grass carp (Ctenopharyngodon idella). The mRNA expression analysis showed that CD80/86, CD28, and CD152 were constitutively expressed in various tissues. Further analysis revealed that CD80/86 was highly expressed in IgM+ B cells. Conversely, CD28 and CD152 were highly expressed in CD4+ and CD8+ T cells. Subcellular localization illustrated that CD80/86, CD28, and CD152 are all located on the cell membrane. A yeast two-hybrid assay exhibited that CD80/86 can bind with both CD28 and CD152. In vivo assay showed that the expression of CD80/86 was rapidly upregulated in Aeromonas hydrophila infected fish compared to the control fish. However, the expression of CD28 and CD152 presented the inverse trend, suggesting that teleost fish may regulate T cell activation through the differential expression of CD28 and CD152. Importantly, we discovered that T cells were more likely to be activated by A. hydrophila after CD152 was blocked by anti-CD152 antibodies. This suggests that the teleost CD152 is an inhibitory receptor of T cell activation, which is similar to the mammalian CD152. Overall, this study begins to define the interaction feature between primordial CD80/86 and its receptors CD28 and CD152 in teleost fish, alongside providing a cross-species understanding of the evolution of the costimulatory signals throughout vertebrates.


Assuntos
Antígenos CD28 , Linfócitos T CD8-Positivos , Animais , Antígenos CD/genética , Antígeno B7-1/genética , Antígenos CD28/genética , Antígenos CD28/metabolismo , Linfócitos T CD8-Positivos/metabolismo , Antígeno CTLA-4/genética , Mamíferos
4.
Pathol Res Pract ; 216(8): 152918, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32616425

RESUMO

AIM: The objective of this study was to discuss the effect of CD152 polymorphisms rs231775, rs3087243 and rs5742909 on the susceptibility to cervical cancer. METHODS: The databases of PubMed, EMBASE, Cochrane Library, ISI Web of Science, Google Scholar Web, CNKI and Wanfang were searched for eligible studies. Chi-square-based Q test examined heterogeneity between included studies, and when Pheterogeneity was less than 0.05, random-effect model was used to calculate odds ratios (ORs) with their 95 % confidence intervals (95 % CIs); or else, fixed-effect model was selected. Sensitivity analysis was implemented to determine the stability of final results through removing enrolled studies one at a time and then re-obtaining overall estimates. Publication bias among included studies was checked employing Begg's funnel plot and Egger's test. RESULTS: CD152 polymorphism rs231775 decreased cervical cancer risk in total analysis under the genetic models of GG vs. AA, GG vs. AA + AG and G vs. A (OR = 0.73, 95 % CI = 0.59-0.91; OR = 0.78, 95 % CI = 0.65-0.94; OR = 0.92, 95 % CI = 0.87-0.98), and so did the polymorphism rs3087243 in total analysis under the comparisons of AA vs. GG, AA + GA vs. GG, AA vs. GG + GA, A vs. G and GA vs. GG (OR = 0.51, 95 % CI = 0.42-0.60; OR = 0.71, 95 % CI = 0.62-0.82; OR = 0.57, 95 % CI = 0.50-0.66; OR = 0.70, 95 % CI = 0.64-0.77; OR = 0.83, 95 % CI = 0.72-0.97). Besides, the polymorphism rs5742909 elevated the disease onset in total analysis under the contrasts of TT vs. CC, TT + CT vs. CC, TT vs. CC + CT, T vs. C and CT vs. CC (OR = 2.66, 95 % CI = 1.75-4.04; OR = 1.54, 95 % CI = 1.24-1.91; OR = 2.13, 95 % CI = 1.12-4.03; OR = 1.44, 95 % CI = 1.17-1.78; OR = 1.49, 95 % CI = 1.22-1.83). CONCLUSION: CD152 polymorphisms rs231775 and rs3087243 significantly decrease the risk of cervical cancer, while rs5742909 may increase the disease risk.


Assuntos
Antígeno CTLA-4/genética , Predisposição Genética para Doença/genética , Neoplasias do Colo do Útero/genética , Feminino , Genótipo , Humanos , Polimorfismo de Nucleotídeo Único
5.
MAbs ; 12(1): 1725365, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32054416

RESUMO

Cytotoxic T-lymphocyte-associated protein 4 (CTLA-4, CD152) is a receptor on T cells that inhibits the cell's functions. Blocking CTLA-4 with an antibody has proven effective for the treatment of cancer patients. Anti-CTLA-4 antibodies currently approved for clinical use can bind to human CTLA-4, but do not cross-react to murine CTLA-4. Here, we report the generation and characterization of a functional humanized antibody, mAb146, against both human and murine CTLA-4. Alanine scanning of CTLA-4 using mammalian cell expression cassette identified the unique epitopes of this novel antibody. In addition to the amino acid residues interacting with ligands CD80 and CD86, an N-glycosylation site on N110, conserved in CTLA-4 of human, monkey, and mouse, was identified as the specific epitope that might contribute to the cross-species binding and function of this antibody. This finding may also contribute to the understanding of the glycosylation of CTLA-4 and its related biologic function. In addition to facilitating preclinical development of anti-CTLA-4 antibodies, mAb146 may be useful as a therapeutic agent.


Assuntos
Anticorpos Monoclonais/imunologia , Antígeno CTLA-4/antagonistas & inibidores , Antígeno CTLA-4/química , Epitopos/química , Epitopos/imunologia , Animais , Reações Cruzadas , Glicosilação , Humanos , Camundongos
6.
J Clin Pathol ; 72(10): 659-662, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31340988

RESUMO

CTLA-4 (cytotoxic T-lymphocyte-associated protein-4) or CD152 is an inhibitory receptor expressed constitutively on CD4+ CD25+ T regulatory lymphocytes and transiently on activated CD4+ and CD8+ T lymphocytes. Its inhibitory function promotes long-lived anergy in immune cells and prevents autoimmunity. Therefore, it plays a crucial role in T cell-mediated autoimmunity, and thus in susceptibility to autoimmune diseases, including systemic lupus erythematosus (SLE). It is encoded by CTLA4 gene in humans. AtoG polymorphism at position +49 of CTLA4 gene is the only polymorphism which changes amino acid sequence from alanine to threonine in the leader sequence, which may affect the function of CTLA-4. Association of CTLA4 polymorphisms with SLE has been investigated in several reports in different ethnic populations from different countries, which have shown highly inconsistent findings. In this review, we have compiled previous studies which have reported the association of CTLA4 A49G polymorphism in SLE and its geographical distribution.


Assuntos
Antígeno CTLA-4/genética , Lúpus Eritematoso Sistêmico/genética , Polimorfismo de Nucleotídeo Único/genética , Autoimunidade , Predisposição Genética para Doença , Geografia , Humanos , Lúpus Eritematoso Sistêmico/imunologia , Linfócitos T Reguladores/imunologia
8.
Endocrine ; 62(1): 159-165, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30078171

RESUMO

PURPOSE: Cytotoxic T-Lymphocyte Antigen 4 (CTLA-4 or CD152) is among the immune checkpoint molecules and its abnormal expression in cancer predisposed individuals might make the person more susceptible to tumor initiation and progression. Considering the implication of single-nucleotide polymorphisms (SNPs) in CTLA-4 gene expression and probably protein function, one can assume the involvement of these SNPs in neoplastic diseases. rs5742909 ( - 318C > T) and rs231775 ( + 49 A > G) are among the most commonly studied SNPs and have been considered as genetic factors related to thyroid diseases. In this cross-sectional study, we aimed to elucidate the association between these SNPs and susceptibility to various types of thyroid cancers. METHODS: We investigated the genetic polymorphisms of - 318C > T and + 49 A > G in the CTLA-4 gene by means of ARMS-PCR and RFLP-PCR, respectively, in 167 patients with thyroid carcinomas (papillary, follicular, and anaplastic). The results were then compared with a group of 100 age-sex matched healthy individuals. RESULTS: A statistically significant association was observed between the presence of G allele in + 49 A > G locus and thyroid carcinoma, when comparing cases and controls (OR = 2.10; 95% CI = 1.35-3.28; P = 0.001) and the frequency of heterozygotes (AG) was higher than homozygotes for allele A (AA), in patients with and papillary thyroid carcinoma (PTC). Regarding Hashimoto's thyroiditis, the frequencies of A allele and AA genotype in PTC patients were higher than Hashimoto patients with no history of cancer (OR = 4.67, 95% CI = 2.70-8.08, P < 0.0001; and, OR = 4.68, 95% CI = 1.84-11.91, P = 0.0012; respectively). However; we observed no difference among allele/genotype frequencies in regards to locus - 318C > T. CONCLUSION: In this study, we observed that G allele in + 49 A > G and possibly lower expression of mutated CTLA-4 molecule, is associated with higher susceptibility to thyroid carcinoma. Although the G allele frequency was higher in thyroid cancer patients, when justified for the presence of lymphocytic thyroiditis, the presence of A allele seemed to increase the odds for PTC in patients with Hashimoto's disease.


Assuntos
Antígeno CTLA-4/genética , Predisposição Genética para Doença , Polimorfismo de Nucleotídeo Único , Neoplasias da Glândula Tireoide/genética , Adulto , Alelos , Estudos de Casos e Controles , Estudos Transversais , Feminino , Frequência do Gene , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade
9.
J Neuroimmunol ; 311: 59-67, 2017 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-28807491

RESUMO

Autism is a complex heterogeneous neurodevelopmental disorder; previous studies have identified altered immune responses among individuals diagnosed with autism. An imbalance in the production of pro- and anti-inflammatory cytokines and transcription factors plays a role in neurodevelopmental behavioral and autism disorders. BTBR T+ Itpr3tf/J (BTBR) mice are used as a model for autism, as they exhibit social deficits, communication deficits, and repetitive behaviors compared with C57BL/6J (B6) mice. The adenosine A2A receptor (A2AR) appears to be a potential target for the improvement of behavioral, inflammatory, immune, and neurological disorders. We investigated the effects of the A2AR antagonist SCH 5826 (SCH) and agonist CGS 21680 (CGS) on IL-21, IL-22, T-bet, T-box transcription factor (T-bet), GATA3 (GATA Binding Protein 3), and CD152 (CTLA-4) expression in BTBR mice. Our results showed that BTBR mice treated with SCH had increased CD4+IL-21+, CD4+IL-22+, CD4+GATA3+, and CD4+T-bet+ and decreased CD4+CTLA-4+ expression in spleen cells compared with BTBR control mice. Moreover, CGS efficiently decreased CD4+IL-21+, CD4+IL-22+, CD4+GATA3+, and CD4+T-bet+ and increased CD4+CTLA-4 production in spleen cells compared with SCH-treated and BTBR control mice. Additionally, SCH treatment significantly increased the mRNA and protein expression levels of IL-21, IL-22, GATA3, and T-bet in brain tissue compared with CGS-treated and BTBR control mice. The augmented levels of IL-21/IL-22 and GATA3/T-bet could be due to altered A2AR signaling. Our results indicate that A2AR agonists may represent a new class of compounds that can be developed for use in the treatment of autistic and neuroimmune dysfunctions.


Assuntos
Transtorno Autístico/patologia , Linfócitos T CD4-Positivos/metabolismo , Citocinas/metabolismo , Fator de Transcrição GATA3/metabolismo , Receptor A2A de Adenosina/metabolismo , Transdução de Sinais/genética , Adenosina/análogos & derivados , Adenosina/farmacologia , Agonistas do Receptor A2 de Adenosina/farmacologia , Antagonistas do Receptor A2 de Adenosina/farmacologia , Animais , Transtorno Autístico/genética , Transtorno Autístico/imunologia , Encéfalo/metabolismo , Linfócitos T CD4-Positivos/efeitos dos fármacos , Modelos Animais de Doenças , Proteínas Fetais/genética , Proteínas Fetais/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/genética , Receptores de Inositol 1,4,5-Trifosfato/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes Neurológicos , Proteínas do Tecido Nervoso/deficiência , Proteínas do Tecido Nervoso/genética , Fenetilaminas/farmacologia , Pirimidinas/farmacologia , Transdução de Sinais/efeitos dos fármacos , Baço/patologia , Proteínas com Domínio T/genética , Proteínas com Domínio T/metabolismo , Triazóis/farmacologia
10.
J Vet Med Sci ; 79(5): 871-875, 2017 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-28392507

RESUMO

Cytotoxic T lymphocyte associated gene-4 (CTLA-4) is a costimulatory molecule, expressed on the surface of activated T cells that negatively regulates T cell activation. In humans, alternative splicing of the CTLA-4 gene generates two major isoforms of mRNA, and a soluble form of CTLA-4 (sCTLA-4) was detected in normal human serum. We describe alternatively spliced mRNA expressed in peripheral blood mononuclear cells obtained from a healthy dog lacking the transmembrane domain coded by exon 3 of the CTLA-4 gene. Immunoprecipitation and western blotting of dog serum revealed a band of approximately 23-kDa, which is consistent with the predicted size, based on the amino acid sequence of the canine sCTLA-4 obtained in this study.


Assuntos
Antígeno CTLA-4/genética , Cães/genética , Processamento Alternativo , Animais , Antígeno CTLA-4/sangue , Expressão Gênica
11.
Oncotarget ; 8(16): 26679-26686, 2017 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-28416762

RESUMO

BACKGROUND: The polymorphisms in cluster of differentiation 152 (CD152) gene have been reported to be associated with breast cancer (BC), but relevant findings were far from conclusive. Therefore, we carried out this meta-analysis to combine those results for a clearer perspective on this issue. RESULTS: In our meta-analysis, a total of 8 eligible publications of 19 case-control studies were selected, which totally contained 7,442 BC cases and 7,376 normal controls. Among the five polymorphisms of CD152 gene, +49 G/A, -1661 A/G and -318 C/T significantly increased the risk of BC under corresponding genetic comparisons; while CT60 G/A polymorphism was negatively related to the cancer susceptibility. In addition, -1772 T/C polymorphism of CD152 gene was not associated with the development of BC. MATERIALS AND METHODS: Online databases and other sources were searched for published studies on the relationship between BC susceptibility and CD152 polymorphisms (+49 G/A, -1661 A/G, -1722 T/C, -318 C/T and CT60 G/A). The strength of association was evaluated with pooled odds ratios (ORs) and their corresponding 95% confidence intervals (95% CIs). Heterogeneity evaluation was conducted via Q test. Sensitivity analysis was used to detect the stability of our results. Begg's funnel plot and Egger's test were applied to investigate publication bias among selected studies. CONCLUSIONS: The polymorphisms +49 G/A, -1661 A/G and -318 C/T may elevate the susceptibility to BC, but the polymorphism CT60 G/A may offer protection against the cancer.


Assuntos
Neoplasias da Mama/genética , Antígeno CTLA-4/genética , Predisposição Genética para Doença , Polimorfismo de Nucleotídeo Único , Alelos , Neoplasias da Mama/patologia , Estudos de Casos e Controles , Feminino , Genótipo , Humanos , Razão de Chances , Viés de Publicação , Medição de Risco , Fatores de Risco
12.
Mol Immunol ; 82: 57-65, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-28027499

RESUMO

Accumulating evidence suggests an association between immune dysfunction and autism disorders in a significant subset of children. In addition, an imbalance between pro- and anti-inflammatory pathways has been proposed to play an important role in the pathogenesis of several neurodevelopmental disorders including autism; however, the role of anti-inflammatory molecules IL-27 and CTLA-4 and pro-inflammatory cytokines IL-21 and IL-22 has not previously been explored in autistic children. In the current study, we investigated the expression of IL-21, IL-22, IL-27, and CD152 (CTLA-4) following an in-vitro immunological challenge of peripheral blood mononuclear cells (PBMCs) from children with autism (AU) or typically-developing children (TD) with phorbol-12-myristate 13-acetate (PMA) and ionomycin. In our study, cells from children with AU had increased IL-21 and IL-22 and decreased CTLA-4 expression on CD4+ T cells as compared with cells from the TD control. Similarly, AU cells showed decreased IL-27 production by CD14+ cells compared to that of TD control cells. These results were confirmed by real-time PCR and western blot analyses. Our study shows dysregulation of the immune balance in cells from autistic children as depicted by enhanced pro-inflammatory cytokines, 'IL-21/IL-22' and decreased anti-inflammatory molecules, 'IL-27/CTLA-4'. Thus, further study of this immune imbalance in autistic children is warranted in order to facilitate development of biomarkers and therapeutics.


Assuntos
Transtorno Autístico/imunologia , Biomarcadores/análise , Citocinas/biossíntese , Citocinas/imunologia , Leucócitos Mononucleares/imunologia , Western Blotting , Antígeno CTLA-4/biossíntese , Antígeno CTLA-4/imunologia , Criança , Pré-Escolar , Estudos Transversais , Feminino , Citometria de Fluxo , Humanos , Inflamação/imunologia , Interleucinas/biossíntese , Interleucinas/imunologia , Masculino , Reação em Cadeia da Polimerase em Tempo Real , Interleucina 22
13.
Tumour Biol ; 37(3): 4143-57, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26490985

RESUMO

Recently, systemic administration of a human monoclonal antibody directed against cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) expressed on circulating T cells in patients with chronic lymphocytic leukaemia (CLL) has been considered. Also, CLL cells have been shown to express CTLA-4, increased levels of which in the leukaemic compartment are a predictor of good clinical outcome. Since both CLL and Treg microenvironment cells can be targeted by the CTLA-4 blocking antibody in this immunotherapy approach, the investigation of the functional effect of CTLA-4 blockade on CLL cells might be of potential clinical relevance. The main aim of this study was to examine the effect of CTLA-4 blockade on proliferation activity and apoptosis of CLL cells in patients with low and high CTLA-4 expression. We found that in the high CTLA-4-expressing CLL group, CTLA-4 blockade on the CLL cell surface resulted in a significant increase in the median percentages of Ki67(+) cells and a tendency to decrease in the proportion of apoptotic cells. In contrast, in the low CTLA-4 expressors, CTLA-4 blockade did not affect the proliferation activity or the frequency of apoptosis. This study reports for the first time the different effect of CTLA-4 blockade on CLL cells in CLL patients depending on the levels of CTLA-4 expression. CTLA-4 blockade seems to induce pro-survival signals in leukaemic cells from CLL patients exhibiting high CTLA-4 expression, suggesting that an immunotherapy approach based on the systemic use of monoclonal anti-CTLA-4 antibodies could be an unfavourable strategy for some CLL patients.


Assuntos
Antígeno CTLA-4/metabolismo , Leucemia Linfocítica Crônica de Células B/metabolismo , Idoso , Idoso de 80 Anos ou mais , Anticorpos Monoclonais/farmacologia , Antineoplásicos/farmacologia , Apoptose , Linfócitos B/fisiologia , Antígeno CTLA-4/imunologia , Estudos de Casos e Controles , Proliferação de Células , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Humanos , Imunoterapia , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Leucemia Linfocítica Crônica de Células B/imunologia , Masculino , Pessoa de Meia-Idade , Células Tumorais Cultivadas
14.
Clin Exp Med ; 16(3): 317-32, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26003188

RESUMO

Previously, we showed that cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) is overexpressed in chronic lymphocytic leukaemia (CLL) and its expression is correlated with the expression of the major regulators of G1 phase progression: cyclins D2 and D3, and cyclin-dependent kinase inhibitory protein 1 (p27 (KIP1) ). In the present study, we blocked CTLA-4 on the surface of both CLL cells and normal B lymphocytes to investigate the impact of CTLA-4 on the expression of the mentioned G1 phase regulators. We found that in CLL patients and in healthy individuals, the median proportions of cyclin D2-positive cells as well as cyclin D3(+) cells significantly decreased following CTLA-4 blockade. Moreover, CTLA-4 blockade led to an increase in the median frequencies of p27 (KIP1) -positive cells, although this increase was marked only in CLL patients. Our study showed that CTLA-4 affects the expression of the key regulators of G1 phase progression in CLL cells as well as in normal B lymphocytes and may contribute to a better understanding of the role of CTLA-4 in the regulation of G1 phase progression.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Regulação da Expressão Gênica , Leucemia Linfocítica Crônica de Células B/patologia , Linfócitos/patologia , Proteínas de Membrana Transportadoras/metabolismo , Idoso , Idoso de 80 Anos ou mais , Ciclo Celular , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
15.
Rev Alerg Mex ; 62(2): 118-24, 2015.
Artigo em Espanhol | MEDLINE | ID: mdl-25958375

RESUMO

BACKGROUND: Allergic rhinitis and bronchial asthma are inflammatory conditions that have increased in prevalence over the past two decades; studies of the inflammatory response in these diseases have determined that T regulatory cells (Treg) have been considered as responsible for allergens tolerance. The expression of CTLA-4 (CD152) in Treg is associated with the functional activity of this population, moreover the expression of 4-1BB (CD137) has a controversial function. OBJECTIVE: To determine the existence of CTLA-4 and 4-1BB in Treg cells in peripheral blood of patients with rhinitis and/or asthma. MATERIAL AND METHOD: A comparative cross-sectional study was done with three groups of patients: 20 subjects with allergic rhinitis, 17 subjects with bronchial asthma and 17 subjects with both disorders; 19 healthy subjects conformed the control group. The frequency of Treg (CD4+, FoxP3+ and CD25hight) and the expression of CD152 and CD137 in these cells were assessed by flow cytometry in peripheral blood. RESULTS: We found that the group of subjects with bronchial asthma (p<0.001) and allergic rhinitis bronchial asthma (p<0.001) showed a significantly lower percentage of Treg (CD4+, CD25hight and FoxP3+) in peripheral blood compared to the healthy subjects controls. Only the group of subjects with bronchial asthma showed a significantly higher percentage of CD152+ (p<0.01) and CD137+ (p<0.01) Treg compared to control group. CONCLUSIONS: Subjects with bronchial asthma and bronchial asthma and allergic rhinitis disorders have a deficiency of CD4+, CD25hight and FoxP3+ Treg in peripheral blood; however, subjects with bronchial asthma had a higher frequency of CD152+ and CD137+ Treg cells.


Antecedentes: la rinitis alérgica y el asma bronquial son enfermedades inflamatorias cuya prevalencia ha aumentado en las últimas dos décadas. Los estudios de la respuesta inflamatoria en estas enfermedades muestran que las células T reguladoras (Treg) participan en la tolerancia inmunológica. La expresión de CTLA-4 (CD152) se asocia con la actividad funcional de esta población y la expresión de 4-1BB (CD137) tiene un papel controvertido. Objetivo: determinar la existencia de CTLA-4 y 4-1BB en las células Treg en sangre periférica de pacientes con rinitis, asma, o ambas. Material y método: estudio transversal comparativo en el que se reclutaron tres grupos de pacientes: 20 sujetos con rinitis alérgica, 17 sujetos con asma bronquial y 17 con ambos padecimientos. Se formó un grupo control de 19 sujetos sanos. Se analizó la frecuencia de células Treg en sangre periférica y la expresión de CD152 y CD137 en los diferentes grupos mediante citometría de flujo. Resultados: se encontró menor frecuencia estadísticamente significativa de células Treg (CD4+, CD25altas y FoxP3+) en los grupos de sujetos con: asma bronquial (p<0.001) y en el grupo de rinitis alérgica con asma bronquial (p<0.05) respecto del grupo de sujetos sanos. Los pacientes con asma bronquial únicamente tuvieron mayor frecuencia de células Treg que expresan CD152 (p <0.01) y CD137 (p<0.01) respecto del grupo control. Conclusiones: los sujetos con asma bronquial y rinitis alérgica y asma bronquial únicamente tienen deficiencia de Treg CD4+, CD25altas y FoxP3+ en sangre periférica y los sujetos con asma bronquial tienen mayor frecuencia de células Treg que expresan CD152 y CD137.

16.
Artigo em Inglês | MEDLINE | ID: mdl-23891730

RESUMO

Studies suggest that inflammation is involved in the neurodegenerative cascade of dementias. Immunological mechanisms may be part of the pathophysiological process in frontotemporal dementia (FTD), but up till now only vague evidence of such mechanisms has been presented. The B7- CD28/CTLA-4 pathway is an important immunological signaling pathway involved in modulation of T cell activation. The aim of this study was to compare the expression of molecules associated with co-stimulatory signaling in peripheral blood mononuclear cells (PBMC) of FTD to Alzheimer disease (AD) and control groups. Our results confirm the previous demonstrated increased expression of CD80 in CD14+ Alzheimer patients T cells but show, for the first time, a reduction in the expression of CTLA-4 in CD4+ FTD cells. As CTLA-4 is the most potent negative regulators of T-cell activation we speculated that peripheral T lymphocytes in FTD are more activated and this could be involved in the neurodegeneration observed in this dementia.


Assuntos
Doença de Alzheimer/patologia , Antígeno CTLA-4/metabolismo , Demência Frontotemporal/patologia , Linfócitos T/metabolismo , Antígenos CD/metabolismo , Linfócitos B/metabolismo , Brasil , Feminino , Antígenos HLA-DR/metabolismo , Humanos , Masculino
17.
Contemp Oncol (Pozn) ; 17(4): 370-7, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24592125

RESUMO

Cytotoxic T lymphocyte-associated antigen 4 (CTLA-4, CD152) and Foxp3 (forkhead box P3) are receptors present on T cells which play a critical role in the down-regulation of antigen-activated immune responses. To evaluate the potential influences of CTLA-4 and Foxp3 on cancer invasiveness, a case-control study was conducted in 86 patients treated for squamous cell laryngeal carcinoma. The abundance of CTLA-4 and Foxp3 gene transcripts in the purified peripheral blood mononuclear cells (PBMCs) by quantitative real-time PCR (qRT-PCR) was determined. The analysis of proteins by Western blot was performed. The relationships between CTLA-4 and Foxp3 gene and protein expression as well as the aggressiveness of tumor determined on pT, type and depth of invasion were investigated. Our work revealed a significant dependence of mRNA CTLA-4 on tumor front grading (TFG) total score (p = 0.04) as well as CTLA-4 protein expression on pT (p = = 0.03) and type of invasion (p = 0.03). Advanced pT3-pT4 tumors with diffuse infiltration and > 14 TFG points were characterized by higher average values of CTLA-4 protein in PBMCs. Our data also demonstrated significant differences between Foxp3 protein levels in relation to pT (p = 0.04), depth of invasion (p = = 0.02) and type of invasion (p = 0.03). In tumors with the highest invasiveness identified by the pT3-pT4 status, deep invasion with involvement of cartilage and diffuse infiltration, the highest Foxp3 protein level was observed. In conclusion, these results suggest an impact of CTLA-4 and Foxp3 in determining proliferative and aggressive potential of laryngeal carcinoma, highlighting the significance of CTLA-4 and Foxp3 as potential predictive indicators.

18.
Mem. Inst. Oswaldo Cruz ; 107(supl.1): 167-173, Dec. 2012. ilus, graf
Artigo em Inglês | LILACS, SES-SP | ID: lil-659755

RESUMO

Leprosy is a spectral disease exhibiting two polar sides, namely, lepromatous leprosy (LL) characterised by impaired T-cell responses and tuberculoid leprosy in which T-cell responses are strong. Proper T-cell activation requires signalling through costimulatory molecules expressed by antigen presenting cells and their ligands on T-cells. We studied the influence of costimulatory molecules on the immune responses of subjects along the leprosy spectrum. The expression of the costimulatory molecules was evaluated in in vitro-stimulated peripheral blood mononuclear cells of lepromatous and tuberculoid patients and healthy exposed individuals (contacts). We show that LL patients have defective monocyte CD86 expression, which likely contributes to the impairment of the antigen presentation process and to patients anergy. Accordingly, CD86 but not CD80 blockade inhibited the lymphoproliferative response to Mycobacterium leprae. Consistent with the LL anergy, there was reduced expression of the positive signalling costimulatory molecules CD28 and CD86 on the T-cells in these patients. In contrast, tuberculoid leprosy patients displayed increased expression of the negative signalling molecules CD152 and programmed death-1 (PD-1), which represents a probable means of modulating an exacerbated immune response and avoiding immunopathology. Notably, the contacts exhibited proper CD86 and CD28 expression but not exacerbated CD152 or PD-1 expression, suggesting that they tend to develop a balanced immunity without requiring immunosuppressive costimulatory signalling.


Assuntos
Adulto , Feminino , Humanos , Masculino , /imunologia , /imunologia , /imunologia , Hanseníase/microbiologia , Mycobacterium leprae/imunologia , Receptor de Morte Celular Programada 1/imunologia , Linfócitos T/imunologia , /metabolismo , /metabolismo , /metabolismo , Estudos de Casos e Controles , Interações Hospedeiro-Parasita , Hanseníase/imunologia , Mycobacterium leprae/fisiologia , Receptor de Morte Celular Programada 1/metabolismo
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