RESUMO
NK cells are contained in the ILC1 group; they are recognized for their antiviral and antitumor cytotoxic capacity; NK cells also participate in other immune response processes through cytokines secretion. However, the mechanisms that regulate these functions are poorly understood since NK cells are not as abundant as other lymphocytes, which has made them difficult to study. Using public databases, we identified that NK cells express mRNA encoding class I myosins, among which Myosin 1g and Myosin 1f are prominent. Therefore, this mini-review aims to generate a model of the probable participation of Myosin 1g and 1f in NK cells, based on information reported about the function of these myosins in other leukocytes.
Assuntos
Células Matadoras Naturais/imunologia , Miosinas/imunologia , Animais , Moléculas de Adesão Celular/imunologia , Movimento Celular , Citocinas/imunologia , HumanosRESUMO
We investigated the function of the newly discovered myosin family protein myosin 18A (Myo18A) in Ab-mediated immunity by generating B cell-conditional Myo18A-deficient mice. Myo18A deficiency led to expansion of bone marrow progenitor B cells and mature B cells in secondary lymphoid organs. Myo18A-deficient mice displayed serum IgM hyperglobulinemia and increased splenic IgM-secreting cells, with older mice switching to IgG1 hyperglobulinemia and autoantibody development. Immunization of Myo18A-deficient mice with inactivated influenza virus led to development of more potent neutralizing Abs against the major Ag hemagglutinin, associated with persistent accumulation of Ag-specific germinal center B cells and more Ag-specific bone marrow plasma cells. In vitro stimulation with TLR7 and BCR ligands revealed a greater ability of Myo18A-deficient B cells to differentiate into Ab-secreting cells, associated with higher AID and Blimp-1 expression. Overall, our study demonstrates that Myo18A is a novel negative regulator of B cell homeostasis, differentiation, and humoral immunity.
Assuntos
Anticorpos Monoclonais/imunologia , Linfócitos B/imunologia , Imunidade Humoral/imunologia , Miosinas/imunologia , Animais , Diferenciação Celular/imunologia , Feminino , Masculino , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Miosinas/deficiênciaRESUMO
Cell migration is a dynamic process that involves adhesion molecules and the deformation of the moving cell that depends on cytoskeletal remodeling and actin-modulating proteins such as myosins. In this work, we analyzed the role of the class I Myosin-1 g (Myo1g) in migratory processes of LPS + IL-4 activated B lymphocytes in vivo and in vitro. In vivo, the absence of Myo1g reduced homing of activated B lymphocytes into the inguinal lymph node. Using microchannel chambers and morphology analysis, we found that the lack of Myo1g caused adhesion and chemotaxis defects. Additionally, deficiency in Myo1g causes flaws in adopting a migratory morphology. Our results highlight the importance of Myo1g during B cell migration.
Assuntos
Linfócitos B/imunologia , Linfonodos/imunologia , Ativação Linfocitária , Antígenos de Histocompatibilidade Menor/imunologia , Miosinas/imunologia , Animais , Linfócitos B/citologia , Adesão Celular , Movimento Celular , Células Cultivadas , Feminino , Camundongos Endogâmicos C57BLRESUMO
OBJECTIVE: Statins have immunomodulatory potential in autoimmune diseases but had not been studied as a disease-modifying agent in inflammatory myopathies. The objective of this study is to assess the effect of simvastatin in an experimental model of autoimmune myositis in mice on muscle strength and histopathology. METHODS: Four groups of mice (n = 5 per group) were selected for experimentally induced myositis. Mice were immunized with 1.5 mg myosin in complete Freund's adjuvant weekly for two times and injected with 500 ng pertussis toxin twice immediately after each immunization. From day 1 before immunization to 10 days after the last immunization, mice were treated with oral simvastatin (10 or 20 or 40 mg/kg) diluted in DMSO. The control group mice were injected with complete Freund's adjuvant weekly for two times and did not receive treatment. Non-immunized mice (n = 5 per group) were treated either with simvastatin (5 mg/kg or 20 mg/kg or 40 mg/kg of simvastatin diluted in DMSO) or with DMSO. RESULTS: Inflammation was observed in myositis groups with positive myositis-specific antibodies. Muscle strength dropped significantly after immunization. Immunized simvastatin 20 mg/kg treated group had significantly higher muscle strength versus non-treated myositis mice and versus other simvastatin doses. Besides, a trend toward higher serum Th17 percentage population was found in immunized non-treated mice, versus immunized simvastatin- treated mice, without significant difference. CONCLUSION: Simvastatin at 20 mg/kg decreases the severity of myositis in experimental autoimmune myositis and is a candidate of being a disease-modifying agent in inflammatory myopathies.
Assuntos
Anti-Inflamatórios/uso terapêutico , Inflamação/tratamento farmacológico , Doença Autoimune do Sistema Nervoso Experimental/tratamento farmacológico , Sinvastatina/uso terapêutico , Células Th17/imunologia , Animais , Autoanticorpos/sangue , Autoantígenos/imunologia , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Força Muscular/efeitos dos fármacos , Miosinas/imunologiaRESUMO
Lymphatic filariasis, a chronic disfiguring disease exhibits complex pathology. Based on different clinical manifestations, infected individuals are categorized into asymptomatic-carriers and chronic-patients. The mechanism behind differential clinical outcomes remains unclear. Roles of filaria-specific B cell responses in filariasis have been documented, whereas the contribution of B1 cell response and poly-specific IgG and IgA in the context of clinical filariasis is not deciphered. In this study, we measured the poly-specific IgG and IgA levels in different clinical categories of filariasis. Asymptomatic-carriers exhibited increased IgG4 antibodies against both filarial-antigens as well as auto-antigens compared to other clinical categories, although IgG against these auto-antigens remained lower. IgA levels against both filarial and auto-antigens were decreased in asymptomatic-carriers. A positive correlation between anti-filarial IgG4 and IgG4 against auto-antigens were observed, suggesting the synergistic role of poly-specific natural IgG4 with anti-filarial IgG4 in blocking the pathogenesis in asymptomatic microfilarial cases.
Assuntos
Anticorpos Anti-Helmínticos/genética , Autoanticorpos/genética , Autoantígenos/genética , Filariose Linfática/imunologia , Imunoglobulina A/genética , Imunoglobulina G/genética , Wuchereria bancrofti/imunologia , Actinas/genética , Actinas/imunologia , Adulto , Animais , Anticorpos Anti-Helmínticos/sangue , Antígenos de Helmintos/sangue , Antígenos de Helmintos/genética , Doenças Assintomáticas , Autoanticorpos/sangue , Autoantígenos/imunologia , Linfócitos B/imunologia , Linfócitos B/parasitologia , DNA de Cadeia Simples/genética , DNA de Cadeia Simples/imunologia , Filariose Linfática/genética , Filariose Linfática/parasitologia , Filariose Linfática/patologia , Feminino , Expressão Gênica , Humanos , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Masculino , Pessoa de Meia-Idade , Miosinas/genética , Miosinas/imunologia , Índice de Gravidade de Doença , Wuchereria bancrofti/patogenicidadeRESUMO
Clinical Trials in Organ Transplantation-18 (CTOT-18) is a follow-up analysis of the 200-subject multicenter heart transplant CTOT-05 cohort. CTOT-18 aimed to identify clinical, epidemiologic, and biologic markers associated with adverse clinical events past 1 year posttransplantation. We examined various candidate biomarkers including serum antibodies, angiogenic proteins, blood gene expression profiles, and T cell alloreactivity. The composite endpoint (CE) included death, retransplantation, coronary stent, myocardial infarction, and cardiac allograft vasculopathy. The mean follow-up was 4.5 ± SD 1.1 years. Subjects with serum anti-cardiac myosin (CM) antibody detected at transplantation and at 12 months had a higher risk of meeting the CE compared to those without anti-CM antibody (hazard ratio [HR] = 2.9, P = .046). Plasma VEGF-A and VEGF-C levels pretransplant were associated with CE (odds ratio [OR] = 13.24, P = .029; and OR = 0.13, P = .037, respectively). Early intravascular ultrasound findings or other candidate biomarkers were not associated with the study outcomes. In conclusion, anti-CM antibody and plasma levels of VEGF-A and VEGF-C were associated with an increased risk of adverse events. Although this multicenter report supports further evaluation of the mechanisms through which anti-CM antibody and plasma angiogenesis proteins lead to allograft injury, we could not identify additional markers of adverse events or potential novel therapeutic targets.
Assuntos
Biomarcadores/metabolismo , Insuficiência Cardíaca/metabolismo , Insuficiência Cardíaca/cirurgia , Transplante de Coração , Adulto , Ensaio de Imunoadsorção Enzimática , Feminino , Seguimentos , Perfilação da Expressão Gênica , Antígenos HLA/imunologia , Humanos , Sistema Imunitário , Masculino , Pessoa de Meia-Idade , Miosinas/imunologia , Neovascularização Patológica , Modelos de Riscos Proporcionais , Estudos Prospectivos , Estudos Retrospectivos , Risco , Linfócitos T/imunologia , Resultado do Tratamento , Fator A de Crescimento do Endotélio Vascular/sangue , Fator C de Crescimento do Endotélio Vascular/sangue , Vimentina/imunologiaRESUMO
BACKGROUND: Anti-myosin antibodies (AMAs) are often formed in response to myocardial infarction (MI) and have been implicated in maladaptive cardiac remodelling. We aimed to: (1) compare AMA formation in patients with Non-ST-Elevation MI (NSTEMI) and ST-Elevation MI (STEMI); (2) evaluate factors predicting autoantibody formation; and, (3) explore their functional significance. METHODS: Immunoglobulin M (IgM) and Immunoglobulin G (IgG) AMA titres were determined in serum samples collected at admission, 3 and 6 months post MI. The relationship between demographic and clinical data, and antibody formation, was investigated to determine factors predicting antibody formation and functional significance. RESULTS: Forty-three (43) patients were consecutively recruited; 74.4% were positive for IgM at admission, compared with 23.3% for IgG. Mean IgG levels increased by 1.24% (±0.28) at 3 months, and 13.55% (±0.13) at 6 months post MI. Mean antibody levels were significantly higher in the NSTEMI cohort at both follow-up time points for IgG (p<0.001, p<0.0001), but not IgM (p=0.910, p=0.066). A moderately positive correlation between infarct size and increase in mean IgM concentration was observed at 3 months (r(98)=0.455; p=0.015). Anti-myosin antibody formation was not associated with an unfavourable outcome at follow-up. CONCLUSIONS: Anti-myosin antibodies are formed in a significant proportion of patients following MI, particularly among those with NSTEMI. While IgM levels fall after infarction, IgG levels increase and persist beyond 6 months of follow-up. This raises the possibility that they may contribute to long-term myocardial damage and dysfunction. Future research should focus on the specific epitopes that are targeted by these antibodies, and their functional significance. This may result in the emergence of novel therapies to attenuate cardiac dysfunction in MI patients.
Assuntos
Autoanticorpos/sangue , Autoimunidade , Infarto do Miocárdio/imunologia , Miosinas/imunologia , Biomarcadores/sangue , Eletrocardiografia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/sangue , Valor Preditivo dos Testes , Prognóstico , Estudos Prospectivos , Fatores de TempoRESUMO
Background Glycosphingolipid accumulation in Fabry cells generates a proinflammatory response that may influence disease evolution and responsiveness to enzyme replacement therapy. This study evaluated incidence, mechanism, and impact of myocarditis in Fabry disease cardiomyopathy ( FDCM ). Methods and Results Myocarditis, defined as CD 3+ T lymphocytes >7/mm2 associated with necrosis of glycolipid-laden myocardiocytes, was retrospectively evaluated in endomyocardial biopsies from 78 patients with FDCM : 13 with maximal wall thickness (MWT) <11 mm (group 1), 17 with MWT 11 to 15 mm (group 2), 30 with MWT 16 to 20 mm (group 3), and 18 with MWT >20 mm (group 4). Myocarditis was investigated by polymerase chain reaction for cardiotropic viruses, by serum antiheart and antimyosin antibodies, and by cardiac magnetic resonance. Myocarditis was recognized at histology in 48 of 78 patients with FDCM (38% of group 1, 41% of group 2, 66% of group 3, and 72% of group 4). Myocarditis was characterized by positive antiheart and antimyosin antibodies and negative polymerase chain reaction for viral genomes. CD 3+ cells/mm2 correlated with myocyte necrosis, antimyosin autoantibody titer, and MWT ( P<0.001, r=0.79; P<0.001, r=0.84; P<0.001, r=0.61, respectively). Cardiac magnetic resonance showed myocardial edema in 24 of 78 patients (31%): 0% of group 1, 23% of group 2, 37% of group 3, and 50% of group 4. Conclusions Myocarditis is detectable at histology in up to 56% of patients with FDCM . It is immune mediated and correlates with disease severity. It can be disclosed by antiheart/antimyosin autoantibodies and in the advanced phase by cardiac magnetic resonance. It may contribute to progression of FDCM and resistance to enzyme replacement therapy.
Assuntos
Cardiomiopatias/imunologia , Doença de Fabry/imunologia , Miocardite/imunologia , Miócitos Cardíacos/metabolismo , Triexosilceramidas/imunologia , Adulto , Idoso , Autoanticorpos/imunologia , Cardiomiopatias/diagnóstico por imagem , Cardiomiopatias/tratamento farmacológico , Cardiomiopatias/patologia , Progressão da Doença , Terapia de Reposição de Enzimas , Doença de Fabry/diagnóstico por imagem , Doença de Fabry/tratamento farmacológico , Doença de Fabry/patologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Imagem Cinética por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Miocardite/diagnóstico por imagem , Miocardite/patologia , Miocárdio/imunologia , Miocárdio/patologia , Miosinas/imunologia , Necrose , Adulto JovemRESUMO
INTRODUCTION: Intracellular reactive oxidant species (ROS) are generated in human airway epithelial cells by the prothrombinase action of Group 1 house dust mite (HDM) allergens and by ligation of viral RNA sensor Toll-like receptors (TLRs). We explored signaling convergence between HDM allergens and TLRs in ROS generation because epithelial cells form the primary barrier against inhaled substances and dictate host responses to allergens and viruses. METHODS: ROS formation by Calu-3 human airway cells was studied by measuring dihydrorhodamine 123 oxidation after activation by polyinosinic:polycytidylic acid (to activate TLR3), CL097 (to activate TLR7), a natural mixture of HDM allergens, or BzATP. RESULTS: TLR4 activation was identified as an indispensable response element for all stimuli, operating downstream from myosin motor activation, pannexon gating for ATP release and the endogenous activation of prothrombin. Exogenous prothrombin activation by HDM allergens was prevented by SGUL 1733, a novel inhibitor of the proteolytic activity of Group 1 HDM allergens, which thus prevented TLR4 from being activated at source. CONCLUSIONS: Our data identify for the first time that endogenously-generated prothrombin and TLR4 form a shared effector mechanism essential to intracellular ROS generation activated by a group 1 HDM allergen (itself a prothrombinase) or by ligation of viral RNA-sensing TLRs. These stimuli operate a confluent signaling pathway in which myosin motors, gating of pannexons, and ADAM 10 lead to prothrombin-dependent activation of TLR4 with a recycling activation of pannexons.
Assuntos
Alérgenos/imunologia , Antígenos de Dermatophagoides/imunologia , Proteínas de Artrópodes/imunologia , Cisteína Endopeptidases/imunologia , Dermatophagoides pteronyssinus/imunologia , Mucosa Respiratória/imunologia , Receptor 4 Toll-Like/imunologia , Animais , Técnicas de Cultura de Células , Linhagem Celular , Conexinas/genética , Conexinas/imunologia , Conexinas/metabolismo , Humanos , Imunidade Inata , Miosinas/imunologia , Miosinas/metabolismo , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/imunologia , Proteínas do Tecido Nervoso/metabolismo , Protrombina/imunologia , Protrombina/metabolismo , RNA Interferente Pequeno/metabolismo , RNA Viral/metabolismo , Espécies Reativas de Oxigênio/imunologia , Espécies Reativas de Oxigênio/metabolismo , Mucosa Respiratória/citologia , Mucosa Respiratória/metabolismo , Transdução de Sinais/imunologia , Receptor 4 Toll-Like/metabolismo , Receptor 7 Toll-Like/genética , Receptor 7 Toll-Like/imunologia , Receptor 7 Toll-Like/metabolismo , Receptor Toll-Like 9/imunologia , Receptor Toll-Like 9/metabolismoAssuntos
Doenças Autoimunes/metabolismo , Colágeno/metabolismo , Miocardite/metabolismo , Miocárdio/metabolismo , Miosinas/administração & dosagem , Viroses/complicações , Animais , Doenças Autoimunes/fisiopatologia , Doenças Autoimunes/virologia , Cardiomiopatias/patologia , Cardiomiopatias/fisiopatologia , Colágeno/classificação , Modelos Animais de Doenças , Fibrose/metabolismo , Fibrose/patologia , Masculino , Miocardite/imunologia , Miocardite/fisiopatologia , Miocardite/virologia , Miocárdio/patologia , Miosinas/efeitos adversos , Miosinas/imunologia , Derrame Pericárdico/induzido quimicamente , Ratos , Ratos Endogâmicos Lew , Viroses/epidemiologiaRESUMO
Background: Rheumatic heart disease (RHD) after group A streptococcus (GAS) infections is heritable and prevalent in Indigenous populations. Molecular mimicry between human and GAS proteins triggers proinflammatory cardiac valve-reactive T cells. Methods: Genome-wide genetic analysis was undertaken in 1263 Aboriginal Australians (398 RHD cases; 865 controls). Single-nucleotide polymorphisms were genotyped using Illumina HumanCoreExome BeadChips. Direct typing and imputation was used to fine-map the human leukocyte antigen (HLA) region. Epitope binding affinities were mapped for human cross-reactive GAS proteins, including M5 and M6. Results: The strongest genetic association was intronic to HLA-DQA1 (rs9272622; P = 1.86 × 10-7). Conditional analyses showed rs9272622 and/or DQA1*AA16 account for the HLA signal. HLA-DQA1*0101_DQB1*0503 (odds ratio [OR], 1.44; 95% confidence interval [CI], 1.09-1.90; P = 9.56 × 10-3) and HLA-DQA1*0103_DQB1*0601 (OR, 1.27; 95% CI, 1.07-1.52; P = 7.15 × 10-3) were risk haplotypes; HLA_DQA1*0301-DQB1*0402 (OR 0.30, 95%CI 0.14-0.65, P = 2.36 × 10-3) was protective. Human myosin cross-reactive N-terminal and B repeat epitopes of GAS M5/M6 bind with higher affinity to DQA1/DQB1 alpha/beta dimers for the 2-risk haplotypes than the protective haplotype. Conclusions: Variation at HLA_DQA1-DQB1 is the major genetic risk factor for RHD in Aboriginal Australians studied here. Cross-reactive epitopes bind with higher affinity to alpha/beta dimers formed by risk haplotypes, supporting molecular mimicry as the key mechanism of RHD pathogenesis.
Assuntos
Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Antígenos HLA/genética , Mimetismo Molecular , Cardiopatia Reumática/genética , Cardiopatia Reumática/imunologia , Infecções Estreptocócicas/genética , Infecções Estreptocócicas/imunologia , Austrália , Proteínas da Membrana Bacteriana Externa/imunologia , Reações Cruzadas/imunologia , Epitopos/imunologia , Genótipo , Antígenos HLA/imunologia , Antígenos HLA-DQ/química , Antígenos HLA-DQ/classificação , Antígenos HLA-DQ/genética , Antígenos HLA-DQ/imunologia , Cadeias alfa de HLA-DQ/química , Cadeias alfa de HLA-DQ/classificação , Cadeias alfa de HLA-DQ/genética , Cadeias alfa de HLA-DQ/imunologia , Haplótipos , Humanos , Miosinas/imunologia , Razão de Chances , Polimorfismo de Nucleotídeo Único/genética , Cardiopatia Reumática/microbiologia , Fatores de Risco , Streptococcus/patogenicidadeRESUMO
Delivery of proteins to the cytosol of living cells is a promising research tool. Delivery of antibodies in particular bears exciting applications such as in vivo tracking of proteins at endogenous expression levels or interference with cellular processes. In spite of the large number of methods published for protein delivery, successful applications so far are rare. A possible explanation for this is a vast overestimation of the delivery efficiency due to the use of inappropriate detection methods and/or unsuitable positive controls for cytosolic delivery. Therefore, we provide strategies for unequivocally detecting cytoplasmic protein delivery and quantifying protein transformation efficiency. Finally, we present a protocol for efficient protein delivery to the cytosol validated using these methods.
Assuntos
Peptídeos Penetradores de Células/metabolismo , Citosol/metabolismo , Portadores de Fármacos , Eletroporação/métodos , Anticorpos de Cadeia Única/metabolismo , Animais , Linhagem Celular , Peptídeos Penetradores de Células/química , Fibroblastos/citologia , Fibroblastos/metabolismo , Citometria de Fluxo , Células HeLa , Humanos , Integrases/genética , Integrases/metabolismo , Miosinas/imunologia , Miosinas/metabolismo , Plasmídeos/química , Plasmídeos/metabolismo , Fixação de Tecidos/métodos , Tubulina (Proteína)/imunologia , Tubulina (Proteína)/metabolismoRESUMO
Natural autoantibodies (NAAb) have a role in maintaining physiological homeostasis and prevention of infections, and have been found in mammalian species tested so far. Albeit NAAb levels rise with age, little is known about the origin, function, regulation and initiation of NAAb in young animals. The present study addressed the presence of IgM and IgG NAAb binding glutamate dehydrogenase (GD), carbonic anhydrase (CA), myosin (MYO) and transferrin (TRANS) from before drinking colostrum until the first 12 weeks of life in plasma of female calves. In addition, NAAb to these four self-antigens were also measured in colostrum and in plasma of their mothers during three weeks before calving. Titers of NAAb binding GD, CA, MYO and TRANS were detected in plasma of cows before calving, in colostrum, and in plasma of calves before and after drinking of colostrum. Levels of NAAb in colostrum were positively related with levels of NAAb in plasma of cows. Before colostrum intake, levels of NAAb in plasma of calves were not related with levels of NAAb in plasma of their mother but were influenced by parity of their mother. After colostrum intake, levels of NAAb in plasma of calves in the first week of life were positively related with levels of NAAb in colostrum. Low NAAb levels in colostrum were related with low NAAb in plasma of calves in the first week of life, but after two weeks of life the relation between colostrum and plasma of calves was absent. In conclusion, NAAb are already present in the unborn calf, and levels of neonatal NAAb during the early weeks of life are affected by levels of maternal NAAb obtained via colostrum.
Assuntos
Autoanticorpos/sangue , Bovinos/imunologia , Imunidade Inata , Imunidade Materno-Adquirida , Animais , Animais Recém-Nascidos/imunologia , Animais Lactentes/imunologia , Autoanticorpos/metabolismo , Autoantígenos , Anidrases Carbônicas/imunologia , Colostro/imunologia , Feminino , Glutamato Desidrogenase/imunologia , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Miosinas/imunologia , Gravidez , Transferrina/imunologiaRESUMO
BACKGROUND: Malaria parasites are transmitted by Anopheles mosquitoes. Although several studies have identified mosquito midgut surface proteins that are putatively important for Plasmodium ookinete invasion, only a few have characterized these protein targets and demonstrated transmission-blocking activity. Molecular information about these proteins is essential for the development of transmission-blocking vaccines (TBV). The aim of the present study was to test three monoclonal antibodies (mAbs), A-140, A-78 and A-10, for their ability to recognize antigens and block oocyst infection of the midgut of Anopheles albimanus, a major malaria vector in Latin America. METHOD: Western-blot of mAbs on antigens from midgut brush border membrane vesicles was used to select antibodies. Three mAbs were tested by membrane feeding assays to evaluate their potential transmission-blocking activity against Plasmodium berghei. The cognate antigens recognized by mAbs with oocyst-reducing activity were determined by immunoprecipitation followed by liquid chromatography tandem mass spectrometry. RESULTS: Only one mAb, A-140, significantly reduced oocyst infection intensity. Hence, its probable protein target in the Anopheles albimanus midgut was identified and characterized. It recognized three high-molecular mass proteins from a midgut brush border microvilli vesicle preparation. Chemical deglycosylation assays confirmed the peptide nature of the epitope recognized by mAb A-140. Immunoprecipitation followed by proteomic identification with tandem mass spectrometry revealed five proteins, presumably extracted together as a complex. Of these, AALB007909 had the highest mascot score and corresponds to a protein with a myosin head motor domain, indicating that the target of mAb A-140 is probably myosin located on the microvilli of the mosquito midgut. CONCLUSION: These results provide support for the participation of myosin in mosquito midgut invasion by Plasmodium ookinetes. The potential inclusion of this protein in the design of new multivalent vaccine strategies for blocking Plasmodium transmission is discussed.
Assuntos
Anopheles/imunologia , Anticorpos Monoclonais/imunologia , Insetos Vetores/imunologia , Malária/transmissão , Miosinas/imunologia , Plasmodium berghei/crescimento & desenvolvimento , Animais , Anopheles/parasitologia , Sistema Digestório/imunologia , Sistema Digestório/parasitologia , Feminino , Insetos Vetores/parasitologia , Malária/parasitologia , Oocistos , ProteômicaRESUMO
The endothelium is the first barrier that leukocytes have to overcome during recruitment to sites of inflamed tissues. The leukocyte extravasation cascade is a complex multistep process that requires the activation of various adhesion molecules and signaling pathways, as well as actin remodeling, in both leukocytes and endothelial cells. Endothelial adhesion molecules, such as E-selectin or ICAM-1, are connected to the actin cytoskeleton via actin-binding proteins (ABPs). Although the contribution of receptor-ligand interactions to leukocyte extravasation has been studied extensively, the contribution of endothelial ABPs to the regulation of leukocyte adhesion and transendothelial migration remains poorly understood. This review focuses on recently published evidence that endothelial ABPs, such as cortactin, myosin, or α-actinin, regulate leukocyte extravasation by controlling actin dynamics, biomechanical properties of endothelia, and signaling pathways, such as GTPase activation, during inflammation. Thus, ABPs may serve as targets for novel treatment strategies for disorders characterized by excessive leukocyte recruitment.
Assuntos
Actinas/imunologia , Cortactina/imunologia , Endotélio Vascular/imunologia , Leucócitos/imunologia , Miosinas/imunologia , Migração Transendotelial e Transepitelial/imunologia , Actinas/genética , Animais , Adesão Celular/genética , Adesão Celular/imunologia , Cortactina/genética , Endotélio Vascular/patologia , Humanos , Inflamação/genética , Inflamação/imunologia , Molécula 1 de Adesão Intercelular/genética , Molécula 1 de Adesão Intercelular/imunologia , Leucócitos/patologia , Miosinas/genética , Pirofosfatases/genética , Pirofosfatases/imunologia , Transdução de Sinais/genética , Transdução de Sinais/imunologia , Migração Transendotelial e Transepitelial/genéticaRESUMO
TLR-mediated recognition of microbial danger induces substantial changes in macrophage migration, adherence, and phagocytosis. Recently, we described the LPS-regulated phosphorylation of many cytoskeleton-associated proteins by phosphoproteomics. The functional role of these cytoskeletal and motor proteins in innate immune cell responses is largely unexplored. Here, we first identified both long-tailed class I myosins Myo1e and Myo1f as important contributors to LPS-triggered macrophage spreading. Mouse bone marrow-derived macrophages and DCs deficient in Myo1e selectively secreted increased amounts of the chemokine CCL2. In addition, the cell surface expression of MHC class II (MHC-II) on both cell types was reduced in the absence of Myo1e. However, transcriptional changes in CCL2 and MHC-II were not observed in the absence of Myo1e, indicating that Myo1e regulates specific intracellular transport processes. The capacity of macrophages and DCs lacking Myo1e to stimulate antigen-specific CD4(+) T-cell proliferation was impaired, consistent with the reduced MHC-II surface protein levels. Surprisingly, in Myo1e-deficient DCs, the proteolytic cleavage of endocytosed antigen was also increased. Together, our results provide evidence for a non-redundant function of the motor protein Myo1e in the regulation of TLR4-controlled, cytoskeleton-associated functional properties of macrophages and DCs, and in induction of a full MHC-II-restricted adaptive immune response.
Assuntos
Linfócitos T CD4-Positivos/imunologia , Células Dendríticas/imunologia , Antígenos de Histocompatibilidade Classe II/imunologia , Macrófagos/imunologia , Miosinas/imunologia , Receptor 4 Toll-Like/imunologia , Animais , Apresentação de Antígeno/efeitos dos fármacos , Células da Medula Óssea/citologia , Células da Medula Óssea/efeitos dos fármacos , Células da Medula Óssea/imunologia , Linfócitos T CD4-Positivos/citologia , Linfócitos T CD4-Positivos/efeitos dos fármacos , Proliferação de Células , Quimiocina CCL2/genética , Quimiocina CCL2/imunologia , Citoesqueleto/química , Citoesqueleto/efeitos dos fármacos , Citoesqueleto/imunologia , Células Dendríticas/citologia , Células Dendríticas/efeitos dos fármacos , Regulação da Expressão Gênica , Antígenos de Histocompatibilidade Classe II/genética , Lipopolissacarídeos/farmacologia , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Miosina Tipo I/genética , Miosina Tipo I/imunologia , Miosinas/deficiência , Miosinas/genética , Cultura Primária de Células , Transdução de Sinais , Receptor 4 Toll-Like/genéticaRESUMO
B-1 cells play an important role in the outcome of infection in schistosomiasis, pneumonia and experimental filariasis. However, no information exists regarding status of B-1 cells in clinical manifestations of human filariasis. We investigated the levels of B-1 cells from the total B cells by flow cytometry. Significantly low levels of B-1 cells and IgM antibodies were detected against a wide variety of autoantigens in microfilariae carriers as compared to endemic controls and patients with chronic pathology. A positive correlation was found between IgM antibodies to actin and ss-DNA. Absorption of plasma with soluble actin, myosin and lipopolysaccharides (LPS) resulted in significant removal of antifilarial antibodies. Affinity-purified anti-ss-DNA antibodies were found to be reactive to filarial antigens and various autoantigens. Further, a positive correlation was found between polyreactive antibodies and B-1 cells in filarial-infected human subjects. After antifilarial treatment, levels of IgM antibodies to ss-DNA, actin, LPS and filarial antigen increased significantly indicating a role of polyreactive naturally occurring antibodies in filarial infection. Our findings add to the existing evidence that the B-cell defect in BALB.Xid mice account for susceptibility to murine filarial infection and indicate an important role for these antibodies in providing host protection against filarial infection.
Assuntos
Subpopulações de Linfócitos B/imunologia , Filariose/imunologia , Imunoglobulina M/sangue , Wuchereria bancrofti , Actinas/imunologia , Adolescente , Adulto , Idoso , Animais , Anticorpos Anti-Helmínticos/sangue , Antígenos de Helmintos/sangue , Antígenos de Helmintos/imunologia , Autoantígenos/imunologia , Criança , DNA de Cadeia Simples/imunologia , Feminino , Filariose/sangue , Humanos , Interleucina-10/sangue , Lipopolissacarídeos/imunologia , Masculino , Microfilárias/imunologia , Pessoa de Meia-Idade , Miosinas/imunologia , Wuchereria bancrofti/imunologia , Adulto JovemRESUMO
AIM: We aimed to investigate the histological and clinical presentations of experimental autoimmune myocarditis (EAM) induced by different immunization schemes. METHODS: Male young Lewis rats were divided into five groups immunized by porcine myocardial myosin: subcutaneously (SC) 2 mg (in two 1-mg doses on day 0 and 7), 0 mg (sham group) subcutaneously into rear footpads (RF), 0.25 mg RF, 0.5 mg RF or 1 mg RF (all RF once on day 0). On day 21, left ventricular (LV) function was assessed by cardiac magnetic resonance imaging and cardiac catheterization. The type and degree of myocardial inflammatory infiltrates were determined by conventional histology and immunohistochemistry. RESULTS: In the SC immunized rats and in the RF sham group, we observed 0% mortality, while in the actively RF immunized rats, mortality was 20, 20 and 44% for the 0.25 mg, 0.5 mg and 1 mg myosin doses respectively. Morbidity as defined by inflammatory infiltrates on haematoxylin and eosin (HE) staining was 22% in the SC immunized rats, 0% in the RF sham group and 100% in all actively RF immunized groups. We observed augmented relative ventricle weight and spleen weight, increased LV end-diastolic pressure, reduced LV developed pressure and reduced LV ejection fraction in all with myosin-immunized RF groups without any systematic dose effect. CONCLUSION: Subcutaneous immunization to the neck and flanks did not induce a reproducible EAM, while RF myosin administration reliably led to EAM. Lower myosin doses seem to induce the complete histological and clinical picture of EAM while being associated with lower mortality, non-specific symptoms and animal distress.
Assuntos
Doenças Autoimunes , Miocardite/imunologia , Miosinas/imunologia , Animais , Imunização , Masculino , Miocárdio/imunologia , Miocárdio/patologia , Miosinas/administração & dosagem , Distribuição Aleatória , Ratos , Ratos Endogâmicos LewRESUMO
OBJECTIVE: To evaluate the potential involvement of anti-Trypanosoma cruzi and cardiac protein antibody (IgG total and isotypes) production and their possible association with different clinical forms of human chronic Chagas disease. METHODS: IgG total and isotypes were measured by ELISA, using epimastigote and trypomastigote forms of T. cruzi as antigens and human cardiac proteins (myosin and troponin T) in sera of patients with indeterminate (IND, n = 72), cardiac (CARD, n = 47) and digestive/cardiodigestive (DIG/CARD-DIG, n = 12) clinical forms of the disease. Samples from uninfected health individuals (CONT, n = 30) and patients with ischaemic cardiomyopathy (ISCH, n = 15) were used as controls. Autoantibody levels were correlated with parameters of cardiac function obtained by electrocardiographic, radiographic and echocardiographic examinations. RESULTS: Fifty five per cent of patients were classified as IND, 35.9% as CARD and 9.1% as DIG/CARD-DIG. Greater total IgG production was observed in IND, CARD and DIG/CARD-DIG chagasic patients than in CONT and ISCH, using trypomastigote, epimastigote and cardiac antigens. Moreover, patients with CARD and DIG/CARD-DIG presented greater total IgG production (trypomastigote and epimastigote antigen) than IND, and a negative correlation was determined between total IgG and left ventricular ejection fraction (LVEF). Patients with IND and CARD presented similar higher levels of total IgG specific to troponin T and myosin than CONT and ISCH individuals. Patients with chronic Chagas disease presented a negative correlation between left ventricular ejection fraction (LVEF) and the production of anti-myosin and troponin T autoantibodies. When grouped as low and high antibody producers and compared with LVEF, we observed that high anti-troponin T (P = 0.042) and myosin (P = 0.013) producers presented lower LVEF than low producers. Moreover, there was a positive correlation (r = 0.9508, P = 0.0001) between the production of troponin T and myosin autoantibodies. CONCLUSION: These findings indicate that increased production of anti-cardiac troponin T and myosin autoantibodies probably influences the left ventricular ejection fraction and could be related to chagasic cardiomyopathy.
Assuntos
Anticorpos Antiprotozoários/sangue , Autoanticorpos/sangue , Cardiomiopatia Chagásica/imunologia , Troponina T/imunologia , Trypanosoma cruzi/imunologia , Adulto , Idoso , Antígenos de Protozoários/imunologia , Estudos de Casos e Controles , Cardiomiopatia Chagásica/complicações , Doença Crônica , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Masculino , Pessoa de Meia-Idade , Miosinas/imunologia , Saúde da População Rural , Adulto JovemRESUMO
The enzyme-linked immunosorbent assay (ELISA) is a widely used technique for detecting antibodies (Abs) and is employed in clinical laboratories to identify Abs against various self-antigens-autoAb development and quantitation. This method relies on specific antigen-Ab interactions where one of the components is immobilized on a solid surface. Using this method, the concentrations of antigens or Ab present in the serum can be quantified with high specificity and accuracy. Here, we describe the detection of autoAbs to various self-antigens with different tissue restriction patterns which includes collagens, k-α1 tubulin, vimentin, and myosin. We also discuss their relevance in monitoring for rejection following solid organ transplantation.