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1.
Int J Nanomedicine ; 14: 8469-8481, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31695375

RESUMO

Background: A pandemic influenza viral strain, influenza A/California/07/2009 (pdmH1N1), has been considered to be a potential issue that needs to be controlled to avoid the seasonal emergence of mutated strains. Materials and methods: In this study, aptamer-antibody complementation was implemented on a multiwalled carbon nanotube-gold conjugated sensing surface with a dielectrode to detect pandemic pdmH1N1. Preliminary biomolecular and dielectrode surface analyses were performed by molecular and microscopic methods. A stable anti-pdmH1N1 aptamer sequence interacted with hemagglutinin (HA) and was compared with the antibody interaction. Both aptamer and antibody attachments on the surface as the basic molecule attained the saturation at nanomolar levels. Results: Aptamers were found to have higher affinity and electric response than antibodies against HA of pdmH1N1. Linear regression with aptamer-HA interaction displays sensitivity in the range of 10 fM, whereas antibody-HA interaction shows a 100-fold lower level (1 pM). When sandwich-based detection of aptamer-HA-antibody and antibody-HA-aptamer was performed, a higher response of current was observed in both cases. Moreover, the detection strategy with aptamer clearly discriminated the closely related HA of influenza B/Tokyo/53/99 and influenza A/Panama/2007/1999 (H3N2). Conclusion: The high performance of the abovementioned detection methods was supported by the apparent specificity and reproducibility by the demonstrated sensing system.


Assuntos
Anticorpos Antivirais/imunologia , Aptâmeros de Nucleotídeos/química , Ouro/química , Vírus da Influenza A Subtipo H1N1/imunologia , Nanotubos de Carbono/química , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/virologia , Pandemias , Suínos/virologia , Animais , Proteínas do Sistema Complemento/metabolismo , Eletrodos , Glicoproteínas de Hemaglutininação de Vírus da Influenza/metabolismo , Limite de Detecção , Nanopartículas Metálicas/química , Reprodutibilidade dos Testes , Transdução Genética
2.
Chem Biodivers ; 16(12): e1900401, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31654480

RESUMO

The complement system participates in host defense by eliminating microorganisms and triggering inflammation. However, insufficient control or exacerbated complement activation contributes to inflammatory diseases. Since promising antioxidant and anti-inflammatory activities have been identified in Arctium lappa L. extracts, this study aims to explore the effect of A. lappa extracts on the lectin pathway (LP) of complement activation. Four extracts were obtained by supercritical extraction using scCO2 with or without ethanol as co-solvent, at different temperatures and pressures (E1: 2.2 mg/mL, E2: 2.6 mg/mL and E3: 2.0 mg/mL, E4: 1.5 mg/mL). To evaluate the effect of A. lappa extracts on the LP activation, an ELISA assay using mannose binding lectin pathway of complement was carried out with C4 detection. All extracts showed a concentration-dependent inhibitory effect on the activation of complement by the LP. The following IC50 were observed for E1, E2, E3 and E4: 179.4 µg/mL, 74.69 µg/mL, 119.1 µg/mL and 72.19 µg/mL, respectively. Our results suggest that A. lappa extracts are potential candidates for the treatment of inflammatory disorders that are complement-related.


Assuntos
Arctium/química , Cromatografia com Fluido Supercrítico/métodos , Proteínas do Sistema Complemento/metabolismo , Lectinas/metabolismo , Extratos Vegetais/química , Arctium/metabolismo , Dióxido de Carbono/química , Proteínas do Sistema Complemento/agonistas , Lectinas/antagonistas & inibidores , Folhas de Planta/química , Folhas de Planta/metabolismo , Temperatura Ambiente
3.
Molecules ; 24(18)2019 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-31505853

RESUMO

Complement (C) activation can underlie the infusion reactions to liposomes and other nanoparticle-based medicines, a hypersensitivity syndrome that can be partially reproduced in animal models. However, the sensitivities and manifestations substantially differ in different species, and C activation may not be the only cause of pathophysiological changes. In order to map the species variation of C-dependent and -independent pseudoallergy (CARPA/CIPA), here we used known C activators and C activator liposomes to compare their acute hemodynamic, hematological, and biochemical effects in rats. These C activators were cobra venom factor (CVF), zymosan, AmBisome (at 2 doses), its amphotericin B-free vehicle (AmBisombo), and a PEGylated cholesterol-containing liposome (PEG-2000-chol), all having different powers to activate C in rat blood. The pathophysiological endpoints measured were blood pressure, leukocyte and platelet counts, and plasma thromboxane B2, while C activation was assessed by C3 consumption using the Pan-Specific C3 assay. The results showed strong linear correlation between C activation and systemic hypotension, pointing to a causal role of C activation in the hemodynamic changes. The observed thrombocytopenia and leukopenia followed by leukocytosis also correlated with C3 conversion in case of C activators, but not necessarily with C activation by liposomes. These findings are consistent with the double hit hypothesis of hypersensitivity reactions (HSRs), inasmuch as strong C activation can fully account for all symptoms of HSRs, but in case of no-, or weak C activators, the pathophysiological response, if any, is likely to involve other activation pathways.


Assuntos
Ativação do Complemento/efeitos dos fármacos , Síndrome de Hipersensibilidade a Medicamentos/tratamento farmacológico , Leucocitose/sangue , Lipossomos/farmacologia , Anfotericina B/química , Anfotericina B/farmacologia , Animais , Colesterol/química , Convertases de Complemento C3-C5/química , Convertases de Complemento C3-C5/farmacologia , Proteínas do Sistema Complemento/química , Proteínas do Sistema Complemento/metabolismo , Síndrome de Hipersensibilidade a Medicamentos/etiologia , Síndrome de Hipersensibilidade a Medicamentos/patologia , Venenos Elapídicos/química , Venenos Elapídicos/farmacologia , Humanos , Hipotensão/sangue , Hipotensão/induzido quimicamente , Leucocitose/induzido quimicamente , Leucopenia/sangue , Leucopenia/induzido quimicamente , Lipossomos/química , Nanopartículas/química , Polietilenoglicóis/química , Ratos , Trombocitopenia/sangue , Trombocitopenia/induzido quimicamente , Zimosan/química , Zimosan/farmacologia
4.
Malar J ; 18(1): 312, 2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31533836

RESUMO

BACKGROUND: Anaemia is a major consequence of malaria, caused by the removal of both infected and uninfected red blood cells (RBCs) from the circulation. Complement activation and reduced expression of complement regulatory proteins (CRPs) on RBCs are an important pathogenic mechanism in severe malarial anaemia in both Plasmodium falciparum and Plasmodium vivax infection. However, little is known about loss of CRPs on RBCs during mild malarial anaemia and in low-density infection. METHODS: The expression of CRP CR1, CD55, CD59, and the phagocytic regulator CD47, on uninfected normocytes and reticulocytes were assessed in individuals from two study populations: (1) P. falciparum and P. vivax-infected patients from a low transmission setting in Sabah, Malaysia; and, (2) malaria-naïve volunteers undergoing P. falciparum induced blood-stage malaria (IBSM). For clinical infections, individuals were categorized into anaemia severity categories based on haemoglobin levels. For IBSM, associations between CRPs and haemoglobin level were investigated. RESULTS: CRP expression on RBC was lower in Malaysian individuals with P. falciparum and P. vivax mild malarial anaemia compared to healthy controls. CRP expression was also reduced on RBCs from volunteers during IBSM. Reduction occurred on normocytes and reticulocytes. However, there was no significant association between reduced CRPs and haemoglobin during IBSM. CONCLUSIONS: Removal of CRPs occurs on both RBCs and reticulocytes during Plasmodium infection even in mild malarial anaemia and at low levels of parasitaemia.


Assuntos
Anemia/parasitologia , Proteínas do Sistema Complemento/genética , Eritrócitos/metabolismo , Malária Falciparum/complicações , Malária Vivax/complicações , Adulto , Proteínas do Sistema Complemento/metabolismo , Eritrócitos/parasitologia , Feminino , Humanos , Malária Falciparum/parasitologia , Malária Vivax/parasitologia , Malásia , Masculino , Pessoa de Meia-Idade , Plasmodium falciparum/fisiologia , Plasmodium vivax/fisiologia , Adulto Jovem
5.
Nat Commun ; 10(1): 3890, 2019 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-31488835

RESUMO

Neurological complications affecting the central nervous system have been reported in adult patients infected by Zika virus (ZIKV) but the underlying mechanisms remain unknown. Here, we report that ZIKV replicates in human and mouse adult brain tissue, targeting mature neurons. ZIKV preferentially targets memory-related brain regions, inhibits hippocampal long-term potentiation and induces memory impairment in adult mice. TNF-α upregulation, microgliosis and upregulation of complement system proteins, C1q and C3, are induced by ZIKV infection. Microglia are found to engulf hippocampal presynaptic terminals during acute infection. Neutralization of TNF-α signaling, blockage of microglial activation or of C1q/C3 prevent synapse and memory impairment in ZIKV-infected mice. Results suggest that ZIKV induces synapse and memory dysfunction via aberrant activation of TNF-α, microglia and complement. Our findings establish a mechanism by which ZIKV affects the adult brain, and point to the need of evaluating cognitive deficits as a potential comorbidity in ZIKV-infected adults.


Assuntos
Encéfalo/virologia , Sinapses/virologia , Replicação Viral , Infecção por Zika virus/virologia , Zika virus/fisiologia , Animais , Comportamento Animal , Encéfalo/metabolismo , Encéfalo/patologia , Proteínas do Sistema Complemento/metabolismo , Modelos Animais de Doenças , Hipocampo/metabolismo , Humanos , Inflamação , Aprendizagem , Masculino , Memória , Transtornos da Memória , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microglia/metabolismo , Microglia/patologia , Neurônios/virologia , Terminações Pré-Sinápticas/metabolismo , Receptores Tipo I de Interleucina-1/genética , Sinapses/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
6.
BMC Med Genomics ; 12(1): 127, 2019 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-31492148

RESUMO

BACKGROUND: Burkholderia mallei (Bm) is a facultative intracellular bacterial pathogen causing highly-fatal glanders in solipeds and humans. The ability of Bm to thrive intracellularly is thought to be related to exploitation of host immune response-related genes and pathways. Relatively little is known of the molecular strategies employed by this pathogen to modulate these pathways and evade intracellular killing. This manuscript seeks to fill gaps in the understanding of the interface between Bm and innate immunity by examining gene expression changes during infection of host monocytes. METHODS: The transcriptome of Bm-infected human Mono Mac-6 (MM6) monocytes was profiled on Affymetrix Human Transcriptome GeneChips 2.0. Gene expression changes in Bm-infected monocytes were compared to those of Burkholderia thailandensis (Bt)-infected monocytes and to uninfected monocytes. The resulting dataset was normalized using Robust Multichip Average and subjected to statistical analyses employing a univariate F test with a random variance model. Differentially expressed genes significant at p < 0.001 were subjected to leave-one-out cross-validation studies and 1st and 3rd nearest neighbor prediction model. Significant probe sets were used to populate human pathways in Ingenuity Pathway Analysis, with statistical significance determined by Fisher's exact test or z-score. RESULTS: The Pattern Recognition Receptor (PRR) pathway was represented among significantly enriched immune response-related human canonical pathways, with evidence of upregulation across both infections. Among members of this pathway, pentraxin-3 was significantly upregulated by Bm- or Bt-infected monocytes. Pentraxin-3 (PTX3) was demonstrated to bind to both Bt and Burkholderia pseudomallei (Bp), but not Bm. Subsequent assays did not identify a role for PTX3 in potentiating complement-mediated lysis of Bt or in enhancing phagocytosis or replication of Bt in human monocytes. CONCLUSION: We report on the novel binding of PTX3 to Bt and Bp, with lack of interaction with Bm, suggesting that a possible evasive mechanism by Bm warrants further exploration. We determined that (1) PTX3 may not play a role in activating the lytic pathway of complement in different bacterial species and that (2) the opsonophagocytic properties of PTX3 should be investigated in different primary or immortalized cell lines representing host phagocytes, given lack of binding of PTX3 to MM6 monocytes.


Assuntos
Burkholderia/imunologia , Proteína C-Reativa/metabolismo , Perfilação da Expressão Gênica , Imunidade Inata , Monócitos/imunologia , Monócitos/microbiologia , Componente Amiloide P Sérico/metabolismo , Anticorpos/metabolismo , Burkholderia/crescimento & desenvolvimento , Linhagem Celular , Proteínas do Sistema Complemento/metabolismo , Humanos , Imunidade Inata/genética , Viabilidade Microbiana , Proteínas Opsonizantes/metabolismo , Fagocitose , Ligação Proteica , Regulação para Cima/genética
7.
Ann Clin Lab Sci ; 49(4): 488-495, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31471338

RESUMO

OBJECTIVE: To investigate the association between complement and inflammatory biomarkers with diabetic nephropathy (DN) in type 2 diabetes mellitus (T2DM). METHODS: Plasma and urinary complement and inflammatory biomarkers were measured in 115 T2DM patients assigned to one of two groups: with DN (n=48) and without DN (n=67). RESULTS: The plasma and urinary levels of C3a, C4d, C5a, sC5b-9 and MBL (mannan-binding lectin) were significantly higher in T2DM patients with DN compared to T2DM patients without DN. The plasma levels of IL-10 and INF-γ, as well as the urinary levels of INF-γ and TNF-α in T2DM patients with DN, were significantly higher than T2DM patients without DN. Both urinary MBL and INF-γ were independent risk factors for DN within T2DM patients (OR, 2.35 (95% CI 2.28-2.64) and 1.17 (95% CI 1.15-1.18); P=0.000 and 0.016, respectively). The area under the receiver-operating-characteristic-curve for urinary MBL was 0.89, with sensitivity 91% and specificity 83% for DN. The area under the receiver-operating-characteristic-curve for INF-γ was 0.84, with sensitivity 86% and specificity 79% based on cutoff values of 1.42 ng/mg and 5.15 pg/mg, respectively. CONCLUSION: This study suggests that urinary INF-γ and MBL levels are independent risk factors with a high predictive power for DN in T2DM patients.


Assuntos
Biomarcadores/sangue , Proteínas do Sistema Complemento/metabolismo , Nefropatias Diabéticas/sangue , Inflamação/sangue , Adulto , Idoso , Área Sob a Curva , Biomarcadores/urina , Proteínas do Sistema Complemento/urina , Nefropatias Diabéticas/urina , Feminino , Humanos , Inflamação/urina , Mediadores da Inflamação/sangue , Mediadores da Inflamação/urina , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Curva ROC
8.
Cell Physiol Biochem ; 53(3): 453-464, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31448885

RESUMO

BACKGROUND/AIMS: Eryptosis, the suicidal death of red blood cells (RBCs), is characterized by phosphatidylserine (PS) exposure at the cell surface. It can be catalysed by a variety of abnormal conditions and diseases. Until now, the many questions surrounding the physiology and pathophysiology of eryptosis have not been sufficiently answered. Recently, we demonstrated IgM and IgA autoantibodies (aab) to induce PS exposure on circulating RBCs of patients with autoimmune haemolytic anaemia (AIHA). However, it remained unclear how these aab lead to eryptosis. METHODS: Serum and plasma samples from patients with clinically relevant AIHA of cold type were used to induce eryptosis in O RBCs. Serum containing fresh complement from healthy donors, antibodies to complement component, and complement factor depleted sera were added to examine the influence of the complement on PS-exposure. RBC bound annexin V PE were analysed by flow cytometry. RESULTS: Eryptosis related to IgM aab was found to be dependent on complement activation and could be effectively inhibited by EDTA, serum heat inactivation and anti-C5. PS exposure increased with sequential activation of the sublytic terminal complement components C5b6, C5b-7 and was most significant at the C5b-8 stage. A decrease was observed following the formation of the lytic membrane attack complex C5b-9, either because of lysis of eryptotic RBCs or because of inhibition of eryptosis by C9. CONCLUSION: Our findings reflect new aspects on RBC destruction in AIHA as well the impact of the terminal complement complexes on the RBC membrane. The striking differences to nucleated cell apoptosis may even have physiological meaning of RBC acting as a buffer of the complement system.


Assuntos
Anemia Hemolítica Autoimune/patologia , Autoanticorpos/farmacologia , Proteínas do Sistema Complemento/metabolismo , Eriptose/efeitos dos fármacos , Imunoglobulina M/imunologia , Anemia Hemolítica Autoimune/sangue , Ativação do Complemento/efeitos dos fármacos , Complemento C5/metabolismo , Ácido Edético/farmacologia , Eritrócitos/citologia , Eritrócitos/efeitos dos fármacos , Eritrócitos/metabolismo , Humanos , Fosfatidilserinas/farmacologia
9.
Ann Biol Clin (Paris) ; 77(4): 447-452, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31339492

RESUMO

The complement system is composed of a set of plasma or membrane proteins. Complement protein deficiencies can be inherited or acquired, through the presence of autoantibodies or through consumption. We evaluated the analytical performance of the Optilite® analyser for the determination of the C3 and C4 levels and for the evaluation of the total complement activity. The intra- and inter-series CVs were evaluated and have showed satisfactory results, the concordances with analysers currently used in the laboratory (BNII® and BCT®, Siemens) are very good, as is the agreement between the serum and plasma samples. We also determined the reference values for the different parameters tested in view of a routine use of Optilite® analyser in the laboratory.


Assuntos
Complemento C3/análise , Complemento C4/análise , Proteínas do Sistema Complemento/análise , Testes Hematológicos/instrumentação , Adulto , Artefatos , Automação Laboratorial/instrumentação , Automação Laboratorial/normas , Análise Química do Sangue/instrumentação , Análise Química do Sangue/métodos , Análise Química do Sangue/normas , Coagulação Sanguínea/fisiologia , Complemento C3/metabolismo , Complemento C4/metabolismo , Proteínas do Sistema Complemento/metabolismo , Contaminação de Equipamentos , Testes Hematológicos/métodos , Testes Hematológicos/normas , Humanos , Padrões de Referência , Reprodutibilidade dos Testes
10.
Int J Mol Sci ; 20(14)2019 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-31331124

RESUMO

Epidermal keratinocyte-derived cutaneous squamous cell carcinoma (cSCC) is the most common metastatic skin cancer with high mortality rates in the advanced stage. Chronic inflammation is a recognized risk factor for cSCC progression and the complement system, as a part of innate immunity, belongs to the microenvironment of tumors. The complement system is a double-edged sword in cancer, since complement activation is involved in anti-tumor cytotoxicity and immune responses, but it also promotes cancer progression directly and indirectly. Recently, the role of several complement components and inhibitors in the regulation of progression of cSCC has been shown. In this review, we will discuss the role of complement system components and inhibitors as biomarkers and potential new targets for therapeutic intervention in cSCC.


Assuntos
Carcinoma de Células Escamosas/etiologia , Proteínas do Sistema Complemento/imunologia , Neoplasias Cutâneas/etiologia , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Carcinoma de Células Escamosas/diagnóstico , Carcinoma de Células Escamosas/epidemiologia , Carcinoma de Células Escamosas/metabolismo , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/imunologia , Transformação Celular Neoplásica/metabolismo , Ativação do Complemento/efeitos dos fármacos , Ativação do Complemento/genética , Ativação do Complemento/imunologia , Proteínas do Sistema Complemento/metabolismo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Queratinócitos/imunologia , Queratinócitos/metabolismo , Queratinócitos/patologia , Terapia de Alvo Molecular , Transdução de Sinais/efeitos dos fármacos , Neoplasias Cutâneas/diagnóstico , Neoplasias Cutâneas/epidemiologia , Neoplasias Cutâneas/metabolismo , Microambiente Tumoral/genética , Microambiente Tumoral/imunologia
11.
Nat Commun ; 10(1): 2961, 2019 07 04.
Artigo em Inglês | MEDLINE | ID: mdl-31273197

RESUMO

Persistent inflammation is a hallmark of many human diseases, including anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) and atherosclerosis. Here, we describe a dominant trigger of inflammation: human serum factor H-related protein FHR1. In vitro, this protein selectively binds to necrotic cells via its N-terminus; in addition, it binds near necrotic glomerular sites of AAV patients and necrotic areas in atherosclerotic plaques. FHR1, but not factor H, FHR2 or FHR3 strongly induces inflammasome NLRP3 in blood-derived human monocytes, which subsequently secrete IL-1ß, TNFα, IL-18 and IL-6. FHR1 triggers the phospholipase C-pathway via the G-protein coupled receptor EMR2 independent of complement. Moreover, FHR1 concentrations of AAV patients negatively correlate with glomerular filtration rates and associate with the levels of inflammation and progressive disease. These data highlight an unexpected role for FHR1 during sterile inflammation, may explain why FHR1-deficiency protects against certain diseases, and identifies potential targets for treatment of auto-inflammatory diseases.


Assuntos
Proteínas Inativadoras do Complemento C3b/metabolismo , Inflamassomos/metabolismo , Monócitos/metabolismo , Monócitos/patologia , Doenças Vasculares/metabolismo , Doenças Vasculares/patologia , Proteína C-Reativa/metabolismo , Proteínas do Sistema Complemento/metabolismo , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Proteínas Imobilizadas/metabolismo , Inflamação/metabolismo , Inflamação/patologia , Mediadores da Inflamação/metabolismo , Interleucina-1beta/metabolismo , Lipoproteínas LDL/metabolismo , Malondialdeído/metabolismo , Modelos Biológicos , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Necrose , Ligação Proteica , Receptores Acoplados a Proteínas-G/metabolismo , Soro/metabolismo , Fosfolipases Tipo C/metabolismo
12.
PLoS Biol ; 17(6): e3000323, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31216278

RESUMO

Multidrug-resistant Neisseria gonorrhoeae is a global health problem. Monoclonal antibody (mAb) 2C7 recognizes a gonococcal lipooligosaccharide epitope that is expressed by >95% of clinical isolates and hastens gonococcal vaginal clearance in mice. Chimeric mAb 2C7 (human immunoglobulin G1 [IgG1]) with an E430G Fc modification that enhances Fc:Fc interactions and hexamerization following surface-target binding and increases complement activation (HexaBody technology) showed significantly greater C1q engagement and C4 and C3 deposition compared to mAb 2C7 with wild-type Fc. Greater complement activation by 2C7-E430G Fc translated to increased bactericidal activity in vitro and, consequently, enhanced efficacy in mice, compared with "Fc-unmodified" chimeric 2C7. Gonococci bind the complement inhibitors factor H (FH) and C4b-binding protein (C4BP) in a human-specific manner, which dampens antibody (Ab)-mediated complement-dependent killing. The variant 2C7-E430G Fc overcame the barrier posed by these inhibitors in human FH/C4BP transgenic mice, for which a single 1 µg intravenous dose cleared established infection. Chlamydia frequently coexists with and exacerbates gonorrhea; 2C7-E430G Fc also proved effective against gonorrhea in gonorrhea/chlamydia-coinfected mice. Complement activation alone was necessary and sufficient for 2C7 function, evidenced by the fact that (1) "complement-inactive" Fc modifications that engaged Fc gamma receptor (FcγR) rendered 2C7 ineffective, nonetheless; (2) 2C7 was nonfunctional in C1q-/- mice, when C5 function was blocked, or in C9-/- mice; and (3) 2C7 remained effective in neutrophil-depleted mice and in mice treated with PMX205, a C5a receptor (C5aR1) inhibitor. We highlight the importance of complement activation for antigonococcal Ab function in the genital tract. Elucidating the correlates of protection against gonorrhea will inform the development of Ab-based gonococcal vaccines and immunotherapeutics.


Assuntos
Ativação do Complemento/imunologia , Gonorreia/imunologia , Neisseria gonorrhoeae/imunologia , Animais , Anticorpos Antibacterianos/imunologia , Anticorpos Monoclonais/metabolismo , Antígenos de Bactérias , Proteína de Ligação ao Complemento C4b/imunologia , Fator H do Complemento/imunologia , Proteínas do Sistema Complemento/imunologia , Proteínas do Sistema Complemento/metabolismo , Epitopos/imunologia , Feminino , Voluntários Saudáveis , Humanos , Imunoglobulina G/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Neisseria gonorrhoeae/patogenicidade
13.
Artigo em Inglês | MEDLINE | ID: mdl-31157175

RESUMO

In pathogens that produce lipooligosaccharide (LOS), sugar residues within the surface-exposed LOS outer core mediate interactions with components of the host immune system, promoting bacterial infection. Many LOS structures are controlled by phase variation mediated by random slipped-strand base mispairing, which can reversibly switch gene expression on or off. Phase variation diversifies the LOS, however its adaptive role is not well-understood. Nontypeable Haemophilus influenzae (NTHi) is an important pathogen that causes a range of illnesses in the upper and lower respiratory tract. In NTHi a phase variable galactosyltransferase encoded by lic2A initiates galactose chain extension of the LOS outer core. The donor substrate for Lic2A, UDP-galactose, is generated from UDP-glucose by UDP-galactose epimerase encoded by galE. Our previous fitness profiling of H. influenzae mutants in a murine lung model showed that the galE mutant had a severe survival defect, while the lic2A mutant's defect was modest, leading us to postulate that unidentified factors act as suppressors of potential defects in a lic2A mutant. Herein we conducted a genome-wide genetic interaction screen to identify genes epistatic on lic2A for survival in the murine lung. An unexpected finding was that galE mutants exhibited restored virulence properties in a lic2A mutant background. We identified an alternative antibody epitope generated by Lic2A in the galE mutant that increased sensitivity to classical complement mediated killing in human serum. Deletion of lic2A or restoration of UDP-galactose synthesis alleviated the galE mutant's virulence defects. These studies indicate that when deprived of its galactosyl substrate, Lic2A acquires an alternative activity leading to increased recognition of NTHi by IgM and decreased survival in the lung model. Biofilm formation was increased by deletion of galE and by increased availability of UDP-GlcNAc precursors that can compete with UDP-galactose production. NTHi's ability to reversibly inactivate lic2A by phase-variation may influence survival in niches of infection in which UDP-Galactose levels are limiting.


Assuntos
Glicosiltransferases/metabolismo , Infecções por Haemophilus/imunologia , Haemophilus influenzae/imunologia , Evasão da Resposta Imune , Imunoglobulina M/imunologia , Lipopolissacarídeos/metabolismo , Pulmão/metabolismo , UDPglucose 4-Epimerase/metabolismo , Animais , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Biofilmes/crescimento & desenvolvimento , Proteínas do Sistema Complemento/metabolismo , Modelos Animais de Doenças , Deleção de Genes , Expressão Gênica , Infecções por Haemophilus/metabolismo , Infecções por Haemophilus/microbiologia , Haemophilus influenzae/genética , Haemophilus influenzae/patogenicidade , Humanos , Pulmão/microbiologia , Camundongos , UDPglucose 4-Epimerase/genética , Difosfato de Uridina/metabolismo , Uridina Difosfato Galactose/metabolismo , Uridina Difosfato Glucose/metabolismo , Virulência/genética
14.
J Med Case Rep ; 13(1): 190, 2019 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-31228952

RESUMO

BACKGROUND: Thrombotic thrombocytopenic purpura and hemolytic uremic syndrome are two forms of thrombotic microangiopathies. They are characterized by severe thrombocytopenia, microangiopathic hemolysis, and thrombosis, leading to a systemic inflammatory response and organ failure. Plasmapheresis is used to treat thrombotic microangiopathies. A different entity known as atypical hemolytic uremic syndrome has garnered more clinical recognition because reported cases have described that it does not respond to standard plasmapheresis. Diclofenac potassium is a non-steroidal anti-inflammatory drug that is used to treat pain. CASE REPORT: A 35-year-old Hispanic man presented to our emergency department with complaints of generalized malaise, fever, and an evanescent skin rash. During admission, he reported the use of diclofenac potassium for back pain on a daily basis for 1 week. He was noted to have peripheral eosinophilia, so he was admitted for suspected drug reaction involving eosinophilia and systemic symptoms. His initial laboratory work-up showed microangiopathic hemolytic anemia and thrombocytopenia. He also experienced a seizure, encephalopathy, and had a PLASMIC score of 7, thus raising concerns for thrombotic thrombocytopenic purpura. He underwent emergent plasmapheresis, which improved his clinical condition. The diagnosis was confirmed by assessing the levels of disintegrin and metalloproteinase with thrombospondin type 1 motif, member 13, which was less than 3%. In addition, his skin biopsy was positive for patchy complement deposition, demonstrating complement dysregulation. CONCLUSION: Thrombotic thrombocytopenic purpura is a rare condition that can be acquired. Our case is rare because it represents the first report of diclofenac potassium-induced thrombotic thrombocytopenic purpura with subjacent complement activation and dysregulation. Early recognition and aggressive management led to a favorable outcome.


Assuntos
Anti-Inflamatórios não Esteroides/efeitos adversos , Diclofenaco/efeitos adversos , Síndrome de Hipersensibilidade a Medicamentos/etiologia , Púrpura Trombocitopênica Trombótica/induzido quimicamente , Adulto , Proteínas do Sistema Complemento/metabolismo , Síndrome de Hipersensibilidade a Medicamentos/metabolismo , Humanos , Masculino , Plasmaferese , Púrpura Trombocitopênica Trombótica/metabolismo
15.
Nat Commun ; 10(1): 2727, 2019 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-31227708

RESUMO

A fundamental challenge in medical microbiology is to characterize the dynamic protein-protein interaction networks formed at the host-pathogen interface. Here, we generate a quantitative interaction map between the significant human pathogen, Streptococcus pyogenes, and proteins from human saliva and plasma obtained via complementary affinity-purification and bacterial-surface centered enrichment strategies and quantitative mass spectrometry. Perturbation of the network using immunoglobulin protease cleavage, mixtures of different concentrations of saliva and plasma, and different S. pyogenes serotypes and their isogenic mutants, reveals how changing microenvironments alter the interconnectivity of the interaction map. The importance of host immunoglobulins for the interaction with human complement proteins is demonstrated and potential protective epitopes of importance for phagocytosis of S. pyogenes cells are localized. The interaction map confirms several previously described protein-protein interactions; however, it also reveals a multitude of additional interactions, with possible implications for host-pathogen interactions involving other bacterial species.


Assuntos
Anticorpos Antibacterianos/metabolismo , Proteínas de Bactérias/metabolismo , Interações Hospedeiro-Patógeno/imunologia , Infecções Estreptocócicas/imunologia , Streptococcus pyogenes/imunologia , Anticorpos Antibacterianos/imunologia , Antígenos de Bactérias/imunologia , Antígenos de Bactérias/metabolismo , Proteínas de Bactérias/imunologia , Cromatografia de Afinidade , Proteínas do Sistema Complemento/imunologia , Proteínas do Sistema Complemento/metabolismo , Mapeamento de Epitopos , Voluntários Saudáveis , Humanos , Espectrometria de Massas , Proteínas Opsonizantes/imunologia , Proteínas Opsonizantes/metabolismo , Ligação Proteica , Mapeamento de Interação de Proteínas , Mapas de Interação de Proteínas/imunologia , Infecções Estreptocócicas/sangue , Infecções Estreptocócicas/microbiologia , Streptococcus pyogenes/metabolismo
16.
J Neuroinflammation ; 16(1): 104, 2019 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-31103039

RESUMO

BACKGROUND: Hypoxia-ischemia (HI) during the perinatal period is one of the most common causes of acute mortality and chronic neurologic morbidity. Hydrogen-rich saline (HS) treatment in neonatal mice has been reported to alleviate brain injury following HI, but the mechanisms involved are not known. METHODS: A modified version of the Rice-Vannucci method for the induction of neonatal HI brain injury was performed on postnatal day 7 mouse pups. Animals or BV2-cells received HS and an AMPK inhibitor at indicative time post-injury. RESULTS: In the current study, we show that HS treatment attenuated the accumulation of CD11b+/CD45high cells, suppressed HI-induced neuro-inflammation, induced microglial anti-inflammatory M2 polarization, was associated with promoting AMPK activation, and inhibited nuclear factor-κB activation as demonstrated both in vivo and in vitro. In addition, HS treatment reversed HI-induced neurological disabilities, was associated with improving damaged synapses, and restored the expression levels of synaptophysin and postsynaptic density protein 95 following HI insult. Furthermore, HI insult which increased levels of complement component C1q, C3, and C3aR1 was observed. Importantly, C1q deposited in the infarct core and lesion boundary zone following HI injury, was found to co-localize within regions of synapse loss, whereas HS treatment reversed these effects of HI on synapse loss and complement component levels. Notably, the AMPK inhibitor reversed the beneficial effects of HS as described above. CONCLUSIONS: These results demonstrate that HS restored behavioral deficits after HI in neonatal mice. These beneficial effects, in part, involve promoting microglia M2 polarization and complement-mediated synapse loss via AMPK activation.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Proteínas do Sistema Complemento/metabolismo , Hipóxia-Isquemia Encefálica/metabolismo , Microglia/metabolismo , Solução Salina/administração & dosagem , Sinapses/metabolismo , Animais , Animais Recém-Nascidos , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Linhagem Celular , Polaridade Celular/efeitos dos fármacos , Polaridade Celular/fisiologia , Ativação Enzimática/efeitos dos fármacos , Ativação Enzimática/fisiologia , Feminino , Hidrogênio/administração & dosagem , Hipóxia-Isquemia Encefálica/tratamento farmacológico , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Aprendizagem em Labirinto/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Microglia/efeitos dos fármacos , Gravidez , Distribuição Aleatória , Sinapses/efeitos dos fármacos
17.
Colloids Surf B Biointerfaces ; 181: 125-133, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31128512

RESUMO

One of the events occurring when a biomaterial is implanted in an host is the protein deposition onto its surface, which might regulate cell responses. When a biomaterial displays a compromised biocompatibility, distinct complement pathways can be activated to produce a foreign body reaction. In this article, we have designed different types of biomaterial surfaces to study the inflammation process. Here, we used different concentrations of (3-glycidoxypropyl)-trimethoxysilane (GPTMS), an organically-modified alkoxysilane as a precursor for the synthesis of various types of sol-gel materials functionalizing coatings for titanium implants to regulate biological responses. Our results showed that greater GPTMS surface concentrations induced greater secretion of TNF-α and IL-10 on RAW 264.7 macrophages. When implanted into rabbit tibia, osseointegration decreased with higher GPTMS concentrations. Interestingly, higher deposition of complement-related proteins C-reactive protein (CRP) and ficolin-2 (FCN2), two main activators of distinct complement pathways, was observed. Taking all together, inflammatory potential increase seems to be GPTMS concentration-dependent. Our results show that a greater adsorption of complement proteins can condition macrophage polarization.


Assuntos
Materiais Biocompatíveis/farmacologia , Proteínas do Sistema Complemento/metabolismo , Macrófagos/efeitos dos fármacos , Silanos/farmacologia , Titânio/farmacologia , Animais , Materiais Biocompatíveis/síntese química , Materiais Biocompatíveis/química , Interleucina-10/biossíntese , Macrófagos/metabolismo , Camundongos , Tamanho da Partícula , Células RAW 264.7 , Coelhos , Silanos/síntese química , Silanos/química , Propriedades de Superfície , Tíbia/efeitos dos fármacos , Tíbia/metabolismo , Titânio/química , Fator de Necrose Tumoral alfa/biossíntese
18.
Immunobiology ; 224(4): 511-517, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31109748

RESUMO

Factor I was first discovered in 1966. Its importance became apparent with the description of the original Factor I deficient patient in Boston in 1967. This patient presented with a hyperactive alternative complement pathway resulting in secondary complement deficiency due to continuous complement consumption. On the basis of these findings, the mechanism of the alternative pathway was worked out. In 1975, the surprise finding was made that elevating levels of Factor I in plasma down-regulated the alternative pathway. Attempts to exploit this finding for clinical use had a long and frustrating history and it was not until 2019 that the first patient was treated with the gene therapy vector for age related macular degeneration by Professor Sir Robert MacLaren in Oxford. This review follows the long and contorted course from initial observations to clinical use of complement Factor I.


Assuntos
Fator I do Complemento/fisiologia , Animais , Ativação do Complemento/genética , Ativação do Complemento/imunologia , Fator I do Complemento/química , Fator I do Complemento/uso terapêutico , Via Alternativa do Complemento/genética , Via Alternativa do Complemento/imunologia , Proteínas do Sistema Complemento/genética , Proteínas do Sistema Complemento/imunologia , Proteínas do Sistema Complemento/metabolismo , Suscetibilidade a Doenças , Humanos , Imunoconglutininas/imunologia , Transdução de Sinais , Relação Estrutura-Atividade
19.
PLoS One ; 14(4): e0214753, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30958840

RESUMO

The complement-like pathway of the African malaria mosquito Anopheles gambiae provides protection against infection by diverse pathogens. A functional requirement for a core set of proteins during infections by rodent and human malaria parasites, bacteria, and fungi suggests a similar mechanism operates against different pathogens. However, the extent to which the molecular mechanisms are conserved is unknown. In this study we probed the biochemical responses of complement-like pathway to challenge by the Gram-positive bacterium Staphyloccocus aureus. Western blot analysis of the hemolymph revealed that S. aureus challenge activates a TEP1 convertase-like activity and promotes the depletion of the protein SPCLIP1. S. aureus challenge did not lead to an apparent change in the abundance of the LRIM1/APL1C complex compared to challenge by the Gram-negative bacterium, Escherichia coli. Following up on this observation using a panel of LRIM1 and APL1C antibodies, we found that E. coli challenge, but not S. aureus, specifically activates a protease that cleaves the C-terminus of APL1C. Inhibitor studies in vivo and in vitro protease assays suggest that a serine protease is responsible for APL1C cleavage. This study reveals that despite different challenges converging on activation of a TEP1 convertase-like activity, the mosquito complement-like pathway also includes pathogen-specific reactions.


Assuntos
Anopheles/metabolismo , Proteínas de Insetos/metabolismo , Animais , Anticorpos/análise , Anticorpos/imunologia , Proteínas do Sistema Complemento/metabolismo , Dimerização , Escherichia coli/patogenicidade , Hemolinfa/metabolismo , Proteínas de Insetos/genética , Proteínas de Insetos/imunologia , Inibidores de Proteases/farmacologia , Proteólise/efeitos dos fármacos , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Proteínas de Ligação a RNA/antagonistas & inibidores , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Serina Proteases/metabolismo , Staphylococcus aureus/patogenicidade , Especificidade por Substrato
20.
Int J Nanomedicine ; 14: 2055-2067, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30988608

RESUMO

Background: Understanding of iron oxide nanoparticles (IONP) interaction with the body milieu is crucial to guarantee their efficiency and biocompatibility in nanomedicine. Polymer coating to IONP, with polyethyleneglycol (PEG) and polyvinylpyrrolidone (PVP), is an accepted strategy to prevent toxicity and excessive protein binding. Aim: The aim of this study was to investigate the feature of IONP adsorption of complement proteins, their activation and consequent inflammatory response as a strategy to further elucidate their biocompatibility. Methods: Three types of IONP with different surface characteristics were used: bare (IONP-bare), coated with PVP (IONP-PVP) and PEG-coated (IONP-PEG). IONPs were incubated with human plasma and adsorbed proteins were identified. BALB/c mice were intravenously exposed to IONP to evaluate complement activation and proinflammatory response. Results: Protein corona fingerprinting showed that PEG surface around IONP promoted a selective adsorption of complement recognition molecules which would be responsible for the complement system activation. Furthermore, IONP-PEG activated in vitro, the complement system and induced a substantial increment of C3a and C4a anaphylatoxins while IONP-bare and IONP-PVP did not. In vivo IONP-PEG induced an increment in complement activation markers (C5a and C5b-9), and proinflammatory cytokines (IL-1ß, IL-6, TNF-α). Conclusion: The engineering of nanoparticles must incorporate the association between complement proteins and nanomedicines, which will regulate the immunostimulatory effects through a selective adsorption of plasma proteins and will enable a safer application of IONP in human therapy.


Assuntos
Proteínas Sanguíneas/metabolismo , Proteínas do Sistema Complemento/metabolismo , Compostos Férricos/química , Inflamação/patologia , Nanopartículas/química , Polietilenoglicóis/química , Adsorção , Anafilatoxinas/metabolismo , Animais , Ativação do Complemento , Humanos , Interleucina-1beta/metabolismo , Masculino , Camundongos Endogâmicos BALB C , Nanopartículas/ultraestrutura , Povidona/química , Coroa de Proteína/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
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