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1.
Nat Commun ; 11(1): 5752, 2020 11 13.
Artigo em Inglês | MEDLINE | ID: mdl-33188207

RESUMO

Efficacious interventions are urgently needed for the treatment of COVID-19. Here, we report a monoclonal antibody (mAb), MW05, with SARS-CoV-2 neutralizing activity by disrupting the interaction of receptor binding domain (RBD) with angiotensin-converting enzyme 2 (ACE2) receptor. Crosslinking of Fc with FcγRIIB mediates antibody-dependent enhancement (ADE) activity by MW05. This activity is eliminated by introducing the LALA mutation to the Fc region (MW05/LALA). Potent prophylactic and therapeutic effects against SARS-CoV-2 are observed in rhesus monkeys. A single dose of MW05/LALA blocks infection of SARS-CoV-2 in prophylactic treatment and clears SARS-CoV-2 in three days in a therapeutic treatment setting. These results pave the way for the development of MW05/LALA as an antiviral strategy for COVID-19.


Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Antivirais/farmacologia , Betacoronavirus/imunologia , Infecções por Coronavirus/terapia , Pneumonia Viral/terapia , Glicoproteína da Espícula de Coronavírus/imunologia , Animais , Anticorpos Antivirais/imunologia , Linhagem Celular , Chlorocebus aethiops , Infecções por Coronavirus/prevenção & controle , Feminino , Células HEK293 , Humanos , Macaca mulatta , Masculino , Pandemias/prevenção & controle , Peptidil Dipeptidase A/metabolismo , Pneumonia Viral/prevenção & controle , Receptores de IgG/genética , Receptores de IgG/imunologia , Receptores Virais/metabolismo , Células Vero , Ligação Viral
2.
Sci Rep ; 10(1): 16615, 2020 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-33024203

RESUMO

Middle East Respiratory Syndrome coronavirus (MERS-CoV) is a highly virulent pathogen that causes Middle East Respiratory Syndrome (MERS). Anti-MERS-CoV antibodies play an integral role in the prevention and treatment against MERS-CoV infections. Bioactivity is a key quality attribute of therapeutic antibodies, and high accuracy and precision are required. The major methods for evaluating the antiviral effect of antiviral antibodies include neutralization assays using live viruses or pseudoviruses are highly variable. Recent studies have demonstrated that the antibody-dependent cellular cytotoxicity (ADCC) activity of antiviral antibodies is more consistent with the virus clearance effect in vivo than neutralization activity. However, no reports evaluating the ADCC activity of anti-MERS antibodies have been published to date. Here, we describe the development of a robust and reliable cell-based reporter gene assay for the determination of ADCC activity of anti-MERS antibodies using 293T/MERS cells stably expressing the spike protein of MERS-CoV (MERS-S) as target cells and the engineered Jurkat/NFAT-luc/FcγRIIIa stably expressing FcγRIIIA and NFAT reporter gene as effector cells. According to the ICH-Q2 analytical method guidelines, we carefully optimized the experimental conditions and assessed the performance of our assay. In addition, we found that the ADCC activity of afucosylated anti-MERS antibodies is higher than their fucosylated counterparts. The establishment of this ADCC determination system provides a novel method for evaluating the bioactivity of anti-MERS antibodies and improving ADCC activity through modification of N-glycosylation of the Fc segment.


Assuntos
Anticorpos Antivirais/análise , Citotoxicidade Celular Dependente de Anticorpos/imunologia , Infecções por Coronavirus/imunologia , Testes Imunológicos de Citotoxicidade/métodos , Coronavírus da Síndrome Respiratória do Oriente Médio/imunologia , Coronavírus da Síndrome Respiratória do Oriente Médio/metabolismo , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Infecções por Coronavirus/virologia , Genes Reporter , Células HEK293 , Humanos , Células Jurkat , Luciferases/genética , Coronavírus da Síndrome Respiratória do Oriente Médio/genética , Fatores de Transcrição NFATC/genética , Receptores de IgG/genética , Receptores de IgG/imunologia , Elementos de Resposta , Glicoproteína da Espícula de Coronavírus/metabolismo , Transfecção
3.
PLoS One ; 15(9): e0238347, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32870938

RESUMO

Highly exposed seronegative (HESN) individuals present a unique setting to study mechanisms of protection against HIV acquisition. As natural killer (NK) cell activation and function have been implicated as a correlate of protection in HESN individuals, we sought to better understand the features of NK cells that may confer protection. We used mass cytometry to phenotypically profile NK cells from a cohort of Beninese sex workers and healthy controls. We found that NK cells from HESN women had increased expression of NKG2A, NKp30 and LILRB1, as well as the Fc receptor CD16, and decreased expression of DNAM-1, CD94, Siglec-7, and NKp44. Using functional assessments of NK cells from healthy donors against autologous HIV-infected CD4+ T cells, we observed that NKp30+ and Siglec-7+ cells had improved functional activity. Further, we found that NK cells from HESN women trended towards increased antibody-dependent cellular cytotoxicity (ADCC) activity; this activity correlated with increased CD16 expression. Overall, we identify features of NK cells in HESN women that may contribute to protection from HIV infection. Follow up studies with larger cohorts are warranted to confirm these findings.


Assuntos
Infecções por HIV/patologia , Células Matadoras Naturais/metabolismo , Adulto , Citotoxicidade Celular Dependente de Anticorpos/imunologia , Antígenos de Diferenciação Mielomonocítica/metabolismo , Feminino , Proteínas Ligadas por GPI/genética , Proteínas Ligadas por GPI/metabolismo , Genótipo , Infecções por HIV/imunologia , Humanos , Células Matadoras Naturais/citologia , Células Matadoras Naturais/imunologia , Lectinas/metabolismo , Modelos Lineares , Receptor 3 Desencadeador da Citotoxicidade Natural/metabolismo , Fenótipo , Receptores de IgG/genética , Receptores de IgG/metabolismo , Profissionais do Sexo
5.
Nat Rev Immunol ; 20(10): 633-643, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32782358

RESUMO

Antibody-dependent enhancement (ADE) is a mechanism by which the pathogenesis of certain viral infections is enhanced in the presence of sub-neutralizing or cross-reactive non-neutralizing antiviral antibodies. In vitro modelling of ADE has attributed enhanced pathogenesis to Fcγ receptor (FcγR)-mediated viral entry, rather than canonical viral receptor-mediated entry. However, the putative FcγR-dependent mechanisms of ADE overlap with the role of these receptors in mediating antiviral protection in various viral infections, necessitating a detailed understanding of how this diverse family of receptors functions in protection and pathogenesis. Here, we discuss the diversity of immune responses mediated upon FcγR engagement and review the available experimental evidence supporting the role of FcγRs in antiviral protection and pathogenesis through ADE. We explore FcγR engagement in the context of a range of different viral infections, including dengue virus and SARS-CoV, and consider ADE in the context of the ongoing SARS-CoV-2 pandemic.


Assuntos
Anticorpos Monoclonais/administração & dosagem , Anticorpos Antivirais/administração & dosagem , Anticorpos Facilitadores/efeitos dos fármacos , Betacoronavirus/efeitos dos fármacos , Infecções por Coronavirus/tratamento farmacológico , Leucócitos/efeitos dos fármacos , Pneumonia Viral/tratamento farmacológico , Receptores de IgG/imunologia , Anticorpos Monoclonais/efeitos adversos , Anticorpos Monoclonais/biossíntese , Anticorpos Neutralizantes/administração & dosagem , Anticorpos Neutralizantes/efeitos adversos , Anticorpos Neutralizantes/biossíntese , Anticorpos Antivirais/efeitos adversos , Anticorpos Antivirais/biossíntese , Betacoronavirus/imunologia , Betacoronavirus/patogenicidade , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Dengue/tratamento farmacológico , Dengue/imunologia , Dengue/virologia , Vírus da Dengue/efeitos dos fármacos , Vírus da Dengue/imunologia , Vírus da Dengue/patogenicidade , Regulação da Expressão Gênica , Interações Hospedeiro-Patógeno/efeitos dos fármacos , Interações Hospedeiro-Patógeno/imunologia , Humanos , Leucócitos/imunologia , Leucócitos/virologia , Pandemias , Pneumonia Viral/imunologia , Pneumonia Viral/virologia , Receptores de IgG/antagonistas & inibidores , Receptores de IgG/genética , Vírus da SARS/efeitos dos fármacos , Vírus da SARS/imunologia , Vírus da SARS/patogenicidade , Síndrome Respiratória Aguda Grave/tratamento farmacológico , Síndrome Respiratória Aguda Grave/imunologia , Síndrome Respiratória Aguda Grave/virologia , Transdução de Sinais , Internalização do Vírus/efeitos dos fármacos
6.
Leukemia ; 34(10): 2635-2647, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32684632

RESUMO

Despite the successes achieved with molecular targeted inhibition of the oncogenic driver Bcr-Abl in chronic myeloid leukemia (CML), the majority of patients still require lifelong tyrosine kinase inhibitor (TKI) therapy. This is primarily caused by resisting leukemic stem cells (LSCs), which prevent achievement of treatment-free remission in all patients. Here we describe the ITIM (immunoreceptor tyrosine-based inhibition motif)-containing Fc gamma receptor IIb (FcγRIIb, CD32b) for being critical in LSC resistance and show that targeting FcγRIIb downstream signaling, by using a Food and Drug Administration-approved BTK inhibitor, provides a successful therapeutic approach. First, we identified FcγRIIb upregulation in primary CML stem cells. FcγRIIb depletion caused reduced serial re-plaiting efficiency and cell proliferation in malignant cells. FcγRIIb targeting in both a transgenic and retroviral CML mouse model provided in vivo evidence for successful LSC reduction. Subsequently, we identified BTK as a main downstream mediator and targeting the Bcr-Abl-FcγRIIb-BTK axis in primary CML CD34+ cells using ibrutinib, in combination with standard TKI therapy, significantly increased apoptosis in quiescent CML stem cells thereby contributing to the eradication of LSCs.. As a potential curative therapeutic approach, we therefore suggest combining Bcr-Abl TKI therapy along with BTK inhibition.


Assuntos
Tirosina Quinase da Agamaglobulinemia/antagonistas & inibidores , Antineoplásicos/farmacologia , Proteínas de Fusão bcr-abl/antagonistas & inibidores , Leucemia Mielogênica Crônica BCR-ABL Positiva/metabolismo , Células-Tronco Neoplásicas/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Receptores de IgG/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos , Animais , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Camundongos , Camundongos Endogâmicos C57BL , Receptores de IgG/genética
7.
Proc Natl Acad Sci U S A ; 117(26): 15160-15171, 2020 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-32541026

RESUMO

IgG antibodies cause inflammation and organ damage in autoimmune diseases such as systemic lupus erythematosus (SLE). We investigated the metabolic profile of macrophages isolated from inflamed tissues in immune complex (IC)-associated diseases, including SLE and rheumatoid arthritis, and following IgG Fcγ receptor cross-linking. We found that human and mouse macrophages undergo a switch to glycolysis in response to IgG IC stimulation, mirroring macrophage metabolic changes in inflamed tissue in vivo. This metabolic reprogramming was required to generate a number of proinflammatory mediators, including IL-1ß, and was dependent on mTOR and hypoxia-inducible factor (HIF)1α. Inhibition of glycolysis, or genetic depletion of HIF1α, attenuated IgG IC-induced activation of macrophages in vitro, including primary human kidney macrophages. In vivo, glycolysis inhibition led to a reduction in kidney macrophage IL-1ß and reduced neutrophil recruitment in a murine model of antibody-mediated nephritis. Together, our data reveal the molecular mechanisms underpinning FcγR-mediated metabolic reprogramming in macrophages and suggest a therapeutic strategy for autoantibody-induced inflammation, including lupus nephritis.


Assuntos
Reprogramação Celular/fisiologia , Nefrite Lúpica/metabolismo , Animais , Células Cultivadas , Dinoprostona/genética , Dinoprostona/metabolismo , Metabolismo Energético , Regulação da Expressão Gênica , Glicólise/fisiologia , Humanos , Imunoglobulina G/metabolismo , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Rim/citologia , Macrófagos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Espécies Reativas de Oxigênio , Receptores de IgG/genética , Receptores de IgG/metabolismo
8.
Proc Natl Acad Sci U S A ; 117(23): 12943-12951, 2020 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-32461366

RESUMO

The IgG Fc domain has the capacity to interact with diverse types of receptors, including the neonatal Fc receptor (FcRn) and Fcγ receptors (FcγRs), which confer pleiotropic biological activities. Whereas FcRn regulates IgG epithelial transport and recycling, Fc effector activities, such as antibody-dependent cellular cytotoxicity (ADCC) and phagocytosis, are mediated by FcγRs, which upon cross-linking transduce signals that modulate the function of effector leukocytes. Despite the well-defined and nonoverlapping functional properties of FcRn and FcγRs, recent studies have suggested that FcγRs mediate transplacental IgG transport, as certain Fc glycoforms were reported to be enriched in fetal circulation. To determine the contribution of FcγRs and FcRn to the maternal-fetal transport of IgG, we characterized the IgG Fc glycosylation in paired maternal-fetal samples from patient cohorts from Uganda and Nicaragua. No differences in IgG1 Fc glycan profiles and minimal differences in IgG2 Fc glycans were noted, whereas the presence or absence of galactose on the Fc glycan of IgG1 did not alter FcγRIIIa or FcRn binding, half-life, or their ability to deplete target cells in FcγR/FcRn humanized mice. Modeling maternal-fetal transport in FcγR/FcRn humanized mice confirmed that only FcRn contributed to transplacental transport of IgG; IgG selectively enhanced for FcRn binding resulted in enhanced accumulation of maternal antibody in the fetus. In contrast, enhancing FcγRIIIa binding did not result in enhanced maternal-fetal transport. These results argue against a role for FcγRs in IgG transplacental transport, suggesting Fc engineering of maternally administered antibody to enhance only FcRn binding as a means to improve maternal-fetal transport of IgG.


Assuntos
Sangue Fetal/imunologia , Antígenos de Histocompatibilidade Classe I/metabolismo , Imunoglobulina G/metabolismo , Troca Materno-Fetal/imunologia , Circulação Placentária/imunologia , Receptores Fc/metabolismo , Animais , Feminino , Antígenos de Histocompatibilidade Classe I/genética , Humanos , Imunoglobulina G/imunologia , Camundongos , Camundongos Transgênicos , Gravidez , Ensaios Clínicos Controlados Aleatórios como Assunto , Receptores Fc/genética , Receptores de IgG/genética , Receptores de IgG/metabolismo
9.
Clin Sci (Lond) ; 134(7): 751-763, 2020 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-32227160

RESUMO

The numbers of macrophages are increased in the lungs of chronic obstructive pulmonary disease (COPD) patients. COPD lung macrophages have reduced ability to phagocytose microbes and efferocytose apoptotic cells. Inhaled corticosteroids (ICSs) are widely used anti-inflammatory drugs in COPD; however, their role beyond suppression of cytokine release has not been explored in COPD macrophages. We have examined the effects of corticosteroids on COPD lung macrophage phenotype and function. Lung macrophages from controls and COPD patients were treated with corticosteroids; effects on gene and protein expression of CD163, CD164, CD206, MERTK, CD64, CD80 and CD86 were studied. We also examined the effect of corticosteroids on the function of CD163, MERTK and cluster of differentiation 64 (CD64). Corticosteroid increased CD163, CD164, CD206 and MERTK expression and reduced CD64, CD80 and CD86 expression. We also observed an increase in the uptake of the haemoglobin-haptoglobin complex (CD163) from 59 up to 81% and an increase in efferocytosis of apoptotic neutrophils (MERTK) from 15 up to 28% following corticosteroid treatment. We observed no effect on bacterial phagocytosis. Corticosteroids alter the phenotype and function of COPD lung macrophages. Our findings suggest mechanisms by which corticosteroids exert therapeutic benefit in COPD, reducing iron available for bacterial growth and enhancing efferocytosis.


Assuntos
Corticosteroides/farmacologia , Dexametasona/farmacologia , Pulmão/efeitos dos fármacos , Macrófagos Alveolares/efeitos dos fármacos , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Idoso , Antígenos CD/genética , Antígenos CD/metabolismo , Antígenos de Diferenciação Mielomonocítica/genética , Antígenos de Diferenciação Mielomonocítica/metabolismo , Apoptose/efeitos dos fármacos , Estudos de Casos e Controles , Células Cultivadas , Técnicas de Cocultura , Feminino , Regulação da Expressão Gênica , Humanos , Ferro/metabolismo , Pulmão/metabolismo , Pulmão/patologia , Macrófagos Alveolares/metabolismo , Macrófagos Alveolares/patologia , Masculino , Pessoa de Meia-Idade , Neutrófilos/efeitos dos fármacos , Neutrófilos/metabolismo , Neutrófilos/patologia , Fenótipo , Doença Pulmonar Obstrutiva Crônica/genética , Doença Pulmonar Obstrutiva Crônica/metabolismo , Doença Pulmonar Obstrutiva Crônica/patologia , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/metabolismo , Receptores de IgG/genética , Receptores de IgG/metabolismo , Transdução de Sinais , c-Mer Tirosina Quinase/genética , c-Mer Tirosina Quinase/metabolismo
10.
BMC Med Genet ; 21(1): 71, 2020 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-32252656

RESUMO

BACKGROUND: Herein, we collected currently published data to comprehensively evaluate the impact of the FCGR2A (Fc fragment of IgG receptor IIa) rs1801274 and MUC5B (mucin 5B, oligomeric mucus/gel-forming) rs35705950 variations on susceptibility to pneumonia diseases. METHODS: We retrieved case-control studies from three online databases and applied the statistical approach of meta-analysis for a series of pooling analyses. RESULTS: A total of fourteen case-control studies were included for FCGR2A rs1801274; while thirty-one case-control studies were included for MUC5B rs35705950. No significant difference between pneumonia cases and controls for FCGR2A rs1801274 was found. However, MUC5B rs35705950 was significantly associated with pneumonia susceptibility in the whole population under the genetic models of allelic T vs. G [OR (odds ratio) =3.78], carrier T vs. G (OR = 3.31), TT vs. GG (OR = 13.66), GT vs. GG (OR = 4.78), GT + TT vs. GG (OR = 5.05), and TT vs. GG + GT (OR = 6.47) (all P < 0.001, Bonferroni-adjusted P < 0.006; false discovery rate-adjusted P < 0.0010). Furthermore, we observed a similar positive result for subgroup analyses of "Caucasian", "Asian", "population-based control", and "idiopathic pulmonary fibrosis". CONCLUSIONS: MUC5B rs35705950, but not FCGR2A rs1801274, increases susceptibility to clinical pneumonia, especially to idiopathic pulmonary fibrosis, in both the Caucasian and Asian populations.


Assuntos
Mucina-5B/genética , Pneumonia/genética , Polimorfismo de Nucleotídeo Único , Receptores de IgG/genética , Alelos , Grupo com Ancestrais do Continente Asiático/genética , Grupo com Ancestrais do Continente Asiático/estatística & dados numéricos , Estudos de Casos e Controles , Grupo com Ancestrais do Continente Europeu/genética , Grupo com Ancestrais do Continente Europeu/estatística & dados numéricos , Frequência do Gene , Estudos de Associação Genética , Predisposição Genética para Doença , Genótipo , Humanos , Fibrose Pulmonar Idiopática/epidemiologia , Fibrose Pulmonar Idiopática/genética , Pneumonia/epidemiologia
11.
Mol Immunol ; 121: 144-158, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32222585

RESUMO

Most of therapeutic monoclonal antibodies belong to the immunoglobulin G1 (IgG1) family; they interact with the Fcγ receptors (FcγRs) at the surface of immune cells to trigger effector functions. The IgG1-Fc N-glycans impact the interaction with FcγRs and are considered a critical quality attribute. Pioneer studies on FcγR N-glycans have unveiled an additional complexity in that the N-glycan linked on the Asn-162 of FcγRIIIa was shown to be directly involved in the strong affinity for afucosylated IgG1. The last few years have thus seen the emergence of many studies investigating the complex influence of FcγRIIIa N-glycans on the interaction with IgG1 through their glycosylation sites or their glycoprofiles. In this context, we performed site-directed mutagenesis along with glycoengineering on FcγRs (FcγRI, FcγRIIaH131/b and FcγRIIIaV158/F158) in an effort to elucidate the impact of FcγRs N-glycans on the interaction with IgG1. Furthermore, we assessed their binding to various trastuzumab glycoforms with an enhanced surface plasmon resonance assay. The FcγRIIIa N-glycans had the highest impact on the interaction with IgG1. More specifically, the N162 glycan positively influenced the affinity (15-fold) for afucosylated IgG1 while the N45 glycan presented a negative impact (2-fold) regardless of the IgG1 glycoforms. Interestingly, only the FcγRIIIa glycoprofile had an impact on the interaction with IgG1 with a 1.5-fold affinity increase when FcγRIIIa displays high-mannose glycans. These results provide invaluable insights into the complex and strong influence of N-glycosylation upon FcγRs/IgG1 binding and are instrumental to further understand the impact of FcγRs N-glycosylation in their natural forms.


Assuntos
Imunoglobulina G/metabolismo , Receptores de IgG/metabolismo , Animais , Células CHO , Cricetulus , Glicosilação , Células HEK293 , Humanos , Imunoglobulina G/imunologia , Manose/metabolismo , Mutagênese Sítio-Dirigida , Polissacarídeos/metabolismo , Engenharia de Proteínas , Isoformas de Proteínas/genética , Isoformas de Proteínas/imunologia , Isoformas de Proteínas/metabolismo , Receptores de IgG/genética , Receptores de IgG/imunologia
12.
Eur J Immunol ; 50(5): 685-694, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32012247

RESUMO

Syncytin-1 is the envelope protein of the human endogenous retrovirus W (HERV-W). It has been related to multiple sclerosis (MS) but its role in cellular immunity and its pathogenic mechanism in the autoimmune context are not fully understood. We analyzed syncytin-1 levels in peripheral blood mononuclear cells (PBMC) subsets from healthy donors, MS patients in relapse or remission, and patients with acute infections by flow cytometry. PBMC cultures were also prepared to analyze protein expression kinetics. MS patients had higher levels of syncytin-1 levels than controls. We found that syncytin-1 is elevated in monocytes during MS relapses and infections. Cells expressing syncytin-1, including monocytes, T and B lymphocytes, and NKs presented mainly an activated phenotype and, upon stimulation with LPS, its levels increased rapidly on antigen-presenting cells. Syncytin-1 ligation promoted the activation of monocytes, as demonstrated by the upregulation of CD80 and the nonclassical subset CD14low CD16+ . Our results suggest an important role for syncytin-1 in the activation of leukocytes. Given that the expression of syncytin-1 is upregulated in MS patients, this protein might be contributing to the autoimmune cascade in the disease.


Assuntos
Retrovirus Endógenos/imunologia , Produtos do Gene env/genética , Monócitos/virologia , Esclerose Múltipla/genética , Esclerose Múltipla/virologia , Proteínas da Gravidez/genética , Adulto , Linfócitos B/efeitos dos fármacos , Linfócitos B/imunologia , Linfócitos B/virologia , Antígeno B7-1/genética , Antígeno B7-1/imunologia , Estudos de Casos e Controles , Retrovirus Endógenos/genética , Feminino , Proteínas Ligadas por GPI/genética , Proteínas Ligadas por GPI/imunologia , Regulação da Expressão Gênica , Produtos do Gene env/imunologia , Humanos , Células Matadoras Naturais/efeitos dos fármacos , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/virologia , Receptores de Lipopolissacarídeos/genética , Receptores de Lipopolissacarídeos/imunologia , Lipopolissacarídeos/farmacologia , Masculino , Pessoa de Meia-Idade , Monócitos/efeitos dos fármacos , Monócitos/imunologia , Esclerose Múltipla/imunologia , Esclerose Múltipla/patologia , Proteínas da Gravidez/imunologia , Cultura Primária de Células , Receptores de IgG/genética , Receptores de IgG/imunologia , Recidiva , Indução de Remissão , Transdução de Sinais , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Linfócitos T/virologia
13.
Eur J Immunol ; 50(5): 656-665, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32027754

RESUMO

Natural Killer (NK) cell responses are regulated by a variety of different surface receptors. While we can determine the overall positive or negative effect of a given receptor on NK cell functions, investigating NK cell regulation in a quantitative way is challenging. To quantitatively investigate individual receptors for their effect on NK cell activation, we chose to functionalize latex beads that have approximately the same size as lymphocytes with defined amounts of specific antibodies directed against distinct activating receptors. This enabled us to investigate NK cell reactivity in a defined, clean, and controllable system. Only CD16 and NKp30 could activate the degranulation of resting human NK cells. CD16, NKG2D, NKp30, NKp44, and NKp46 were able to activate cultured NK cells. NK cell activation resulted in the induction of polyfunctional cells that degranulated and produced IFN-γ and MIP-1ß. Interestingly, polyfunctional NK cells were only induced by triggering ITAM-coupled receptors. NKp44 showed a very sensitive response pattern, where a small increase in receptor stimulation caused maximal NK cell activity. In contrast, stimulation of 2B4 induced very little NK cell degranulation, while providing sufficient signal for NK cell adhesion. Our data demonstrate that activating receptors differ in their effectiveness to stimulate NK cells.


Assuntos
Anticorpos/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Células Matadoras Naturais/efeitos dos fármacos , Ativação Linfocitária/efeitos dos fármacos , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/imunologia , Anticorpos/química , Adesão Celular/efeitos dos fármacos , Degranulação Celular/efeitos dos fármacos , Células Cultivadas , Proteínas Ligadas por GPI/genética , Proteínas Ligadas por GPI/imunologia , Humanos , Interferon gama/genética , Interferon gama/imunologia , Células Matadoras Naturais/citologia , Células Matadoras Naturais/imunologia , Microesferas , Subfamília K de Receptores Semelhantes a Lectina de Células NK/genética , Subfamília K de Receptores Semelhantes a Lectina de Células NK/imunologia , Receptor 1 Desencadeador da Citotoxicidade Natural/genética , Receptor 1 Desencadeador da Citotoxicidade Natural/imunologia , Receptor 2 Desencadeador da Citotoxicidade Natural/genética , Receptor 2 Desencadeador da Citotoxicidade Natural/imunologia , Receptor 3 Desencadeador da Citotoxicidade Natural/genética , Receptor 3 Desencadeador da Citotoxicidade Natural/imunologia , Ligação Proteica , Receptores de IgG/genética , Receptores de IgG/imunologia , Transdução de Sinais
14.
Transfusion ; 60(4): 815-821, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32072650

RESUMO

BACKGROUND: Neutrophil specific Fcγ receptor IIIb (CD16b) is a low-affinity IgG receptor. Its polymorphic variants are associated with human neutrophil antigens (HNA). HNA-1a and HNA-1b differ in four amino acids. Immunization can lead to the production of alloantibodies. The exact contribution of four amino acid exchanges for the formation of HNA-1a, -1b epitopes is currently unknown. STUDY DESIGN AND METHODS: Permutation of each polymorphic amino acid from wild-type CD16b cDNA constructs was performed and expressed on HEK293 cells. All 16 receptor variants were produced and tested against 19 well-characterized HNA antisera in an antigen capture assay. RESULTS: Analyzing the reaction pattern revealed that anti-HNA-1a antibodies can bind whenever asparagine (N) is present in position 65, regardless of the three other positions (CD16b *N**). Anti-HNA-1b antibodies can bind when serine (S) is present in position 36 (CD16b S***), when N is present in position 82 (CD16b **N*), or both (CD16b S*N*). CD16b variants with N65 and S36 and/or N82 (such as CD16b SNN*) bind both, anti-HNA-1a and anti-HNA-1b alloantibodies. If these specific amino acids are missing (as in CD16b RSD*), no antibodies will bind. CONCLUSION: Whereas the primary structure of HNA-1a and HNA-1b usually differs in four amino acids, epitope composition is not "antithetical". N65 alone determines the presence of HNA-1a, and S36 and/or N82 determine the presence of HNA-1b. Amino acid 106 does not participate in epitope formation. Our findings are of specific relevance when a HNA-1 phenotype is predicted from a genotype.


Assuntos
Isoantígenos/imunologia , Receptores de IgG/imunologia , Sequência de Aminoácidos , Complexo Antígeno-Anticorpo/genética , Sítios de Ligação de Anticorpos/genética , DNA Complementar , Proteínas Ligadas por GPI/genética , Proteínas Ligadas por GPI/imunologia , Variação Genética , Células HEK293 , Humanos , Isoanticorpos/metabolismo , Isoantígenos/química , Receptores de IgG/genética
15.
Artif Cells Nanomed Biotechnol ; 48(1): 620-626, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32072832

RESUMO

Aim: To analyze the impact of CD32a polymorphism rs1801274 on the occurrence of Kawasaki disease (KD) through the meta-analysis.Methods: The correlation between CD32a polymorphism rs1801274 and the susceptibility to KD was appraised using summarized odds ratios (ORs) with their 95% confidence intervals (95% CIs). Besides, stratification analyses were further implemented on the basis of ethnicity and control source, respectively. Between-study heterogeneity was checked adopting chi-square-based Q test, with p < .05 as significant level. And results from Q test determined which model would be employed for OR calculation, fixed- or random-effects. Sensitivity analysis was accomplished to test the stability of final results. Potential publication bias among included studies was investigated using Begg's funnel plot and Egger's test. If publication bias was significant, its influence on overall estimates would be measured adopting the trim-and-fill method.Results: CD32a polymorphism rs1801274 significantly increased KD risk in total analysis under the comparisons of AA vs. GG, AA + AG vs. GG, AA vs. GG + AG, A vs. G and AG vs. GG (OR = 2.69, 95% CI = 1.39-5.20; OR = 2.00, 95% CI = 1.23-3.26; OR = 1.90, 95% CI = 1.23-2.94; OR = 1.77, 95% CI = 1.34-2.34; OR = 1.53, 95% CI = 1.07-2.19). After stratification analysis by ethnicity, similar tendency was also observed in Caucasian and Asian subgroups under corresponding genetic models. And parallel results were replicated in population-based and other-source subgroups after stratified analysis by control source, under some contrasts.Conclusion: CD32a polymorphism rs1801274 has strong relation to KD onset, and the presence of its A allele could elevate the disease incidence.


Assuntos
Predisposição Genética para Doença/genética , Síndrome de Linfonodos Mucocutâneos/genética , Receptores de IgG/genética , Alelos , Estudos de Associação Genética , Humanos , Razão de Chances , Polimorfismo de Nucleotídeo Único , Risco
16.
Neurobiol Aging ; 88: 24-32, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31901293

RESUMO

Transcriptomics has become an important tool for identification of biological pathways dysregulated in Alzheimer's disease (AD). We performed a network-based gene expression analysis of blood-based microarray gene expression profiles using 2 independent cohorts, Alzheimer's Disease Neuroimaging Initiative (ADNI; N = 661) and AddNeuroMed (N = 674). Weighted gene coexpression network analysis identified 17 modules from ADNI and 13 from AddNeuroMed. Four of the modules derived in ADNI were significantly related to AD; 5 modules in AddNeuroMed were significant. Gene-set enrichment analysis of the AD-related modules identified and replicated 3 biological pathways including the Fc gamma receptor-mediated phagocytosis pathway. Module-based association analysis showed the AD-related module, which has the 3 pathways, to be associated with cognitive function and neuroimaging biomarkers. Gene-based association analysis identified PRKCD in the Fc gamma receptor-mediated phagocytosis pathway as being significantly associated with cognitive function and cerebrospinal fluid biomarkers. The identification of the Fc gamma receptor-mediated phagocytosis pathway implicates the peripheral innate immune system in the pathophysiology of AD. PRKCD is known to be related to neurodegeneration induced by amyloid-ß.


Assuntos
Doença de Alzheimer/genética , Perfilação da Expressão Gênica/métodos , Expressão Gênica , Estudos de Associação Genética , Fagocitose/genética , Proteína Quinase C-delta , Receptores de IgG/genética , Receptores de IgG/fisiologia , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , Transcriptoma/genética , Doença de Alzheimer/imunologia , Doença de Alzheimer/psicologia , Peptídeos beta-Amiloides/metabolismo , Cognição , Imunidade Inata
17.
Immunity ; 52(1): 136-150.e6, 2020 01 14.
Artigo em Inglês | MEDLINE | ID: mdl-31940267

RESUMO

Effector CD8+ T cells are important mediators of adaptive immunity, and receptor-ligand interactions that regulate their survival may have therapeutic potential. Here, we identified a subset of effector CD8+ T cells that expressed the inhibitory fragment crystallizable (Fc) receptor FcγRIIB following activation and multiple rounds of division. CD8+ T cell-intrinsic genetic deletion of Fcgr2b increased CD8+ effector T cell accumulation, resulting in accelerated graft rejection and decreased tumor volume in mouse models. Immunoglobulin G (IgG) antibody was not required for FcγRIIB-mediated control of CD8+ T cell immunity, and instead, the immunosuppressive cytokine fibrinogen-like 2 (Fgl2) was a functional ligand for FcγRIIB on CD8+ T cells. Fgl2 induced caspase-3/7-mediated apoptosis in Fcgr2b+, but not Fcgr2b-/-, CD8+ T cells. Increased expression of FcγRIIB correlated with freedom from rejection following withdrawal from immunosuppression in a clinical trial of kidney transplant recipients. Together, these findings demonstrate a cell-intrinsic coinhibitory function of FcγRIIB in regulating CD8+ T cell immunity.


Assuntos
Apoptose/imunologia , Linfócitos T CD8-Positivos/imunologia , Fibrinogênio/imunologia , Receptores de IgG/imunologia , Adulto , Idoso , Animais , Caspase 3/imunologia , Caspase 7/imunologia , Linhagem Celular Tumoral , Feminino , Fibrinogênio/genética , Rejeição de Enxerto/imunologia , Humanos , Imunoglobulina G/imunologia , Imunossupressão , Masculino , Melanoma Experimental , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pessoa de Meia-Idade , Receptores de IgG/genética , Adulto Jovem
18.
BMC Cancer ; 20(1): 65, 2020 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-31992246

RESUMO

BACKGROUND: Osteosarcoma is a primary malignant tumor originating from mesenchymal tissue, with a poor distant metastasis prognosis. The molecular mechanisms of osteosarcoma metastasis are extremely complicated. METHODS: A public data series (GSE21257) was used to identify differentially expressed genes (DEGs) in osteosarcoma patients that did, or did not, develop metastases. Functional enrichment analysis, a protein-protein interaction network, and survival analysis of DEGs were performed. DEGs with a prognostic value were considered as candidate genes and their functional predictions, different expression in normal and malignant tissues, and immune infiltration were analyzed. RESULTS: The DEGs were mainly enriched in the immune response. Three candidate genes (ALOX5AP, CD74, and FCGR2A) were found, all of which were expressed at higher levels in lungs and lymph nodes than in matched cancer tissues and were probably expressed in the microenvironment. CONCLUSIONS: Candidate genes can help us understand the molecular mechanisms underlying osteosarcoma metastasis and provide targets for future research.


Assuntos
Proteínas Ativadoras de 5-Lipoxigenase/genética , Antígenos de Diferenciação de Linfócitos B/genética , Neoplasias Ósseas/mortalidade , Perfilação da Expressão Gênica/métodos , Antígenos de Histocompatibilidade Classe II/genética , Osteossarcoma/mortalidade , Receptores de IgG/genética , Neoplasias Ósseas/genética , Bases de Dados Genéticas , Regulação Neoplásica da Expressão Gênica , Redes Reguladoras de Genes , Humanos , Metástase Neoplásica , Osteossarcoma/genética , Prognóstico , Análise de Sobrevida , Microambiente Tumoral
19.
Nat Commun ; 11(1): 15, 2020 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-31900413

RESUMO

DNA methylation and blood circulating proteins have been associated with many complex disorders, but the underlying disease-causing mechanisms often remain unclear. Here, we report an epigenome-wide association study of 1123 proteins from 944 participants of the KORA population study and replication in a multi-ethnic cohort of 344 individuals. We identify 98 CpG-protein associations (pQTMs) at a stringent Bonferroni level of significance. Overlapping associations with transcriptomics, metabolomics, and clinical endpoints suggest implication of processes related to chronic low-grade inflammation, including a network involving methylation of NLRC5, a regulator of the inflammasome, and associated pQTMs implicating key proteins of the immune system, such as CD48, CD163, CXCL10, CXCL11, LAG3, FCGR3B, and B2M. Our study links DNA methylation to disease endpoints via intermediate proteomics phenotypes and identifies correlative networks that may eventually be targeted in a personalized approach of chronic low-grade inflammation.


Assuntos
Proteínas Sanguíneas/genética , Inflamação/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Quimiocina CXCL10/genética , Estudos de Coortes , Ilhas de CpG , Metilação de DNA , Epigenoma , Epigenômica , Feminino , Proteínas Ligadas por GPI/genética , Alemanha , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Masculino , Pessoa de Meia-Idade , Proteômica , Receptores de IgG/genética
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