RESUMO
In this review we discuss the effects of microbial exposure on the B cell repertoire. Neonatal exposure to conserved bacterial carbohydrates and phospholipids permanently reprograms the natural antibody repertoire directed toward these antigens by clonal expansion, alterations in clonal dominance, and increased serum antibody levels. These epitopes are present not only in bacterial cell walls, but also in common environmental allergens. Neonatal immunization with bacterial polysaccharide vaccines results in attenuated allergic airway responses to fungi-, house dust mite-, and cockroach-associated allergens in mouse models. The similarities between mouse and human natural antibody repertoires suggest that reduced microbial exposure in children may have the opposite effect, providing a potential mechanistic explanation for the hygiene hypothesis. We propose that understanding the effects of childhood infections on the natural antibody repertoire and the mechanisms of antibody-mediated immunoregulation observed in allergy models will lead to the development of prevention/interventional strategies for treatment of allergic asthma.
Assuntos
Alérgenos/imunologia , Anticorpos/imunologia , Hipersensibilidade Respiratória/imunologia , Animais , Anticorpos/sangue , Linfócitos B/imunologia , Linfócitos B/metabolismo , Bactérias/imunologia , Interações Hospedeiro-Patógeno/imunologia , Humanos , Hipersensibilidade Respiratória/sangue , Hipersensibilidade Respiratória/metabolismo , Hipersensibilidade Respiratória/microbiologiaRESUMO
Innate lymphoid cells (ILCs) regulate stromal cells, epithelial cells and cells of the immune system, but their effect on B cells remains unclear. Here we identified RORγt(+) ILCs near the marginal zone (MZ), a splenic compartment that contains innate-like B cells highly responsive to circulating T cell-independent (TI) antigens. Splenic ILCs established bidirectional crosstalk with MAdCAM-1(+) marginal reticular cells by providing tumor-necrosis factor (TNF) and lymphotoxin, and they stimulated MZ B cells via B cell-activation factor (BAFF), the ligand of the costimulatory receptor CD40 (CD40L) and the Notch ligand Delta-like 1 (DLL1). Splenic ILCs further helped MZ B cells and their plasma-cell progeny by coopting neutrophils through release of the cytokine GM-CSF. Consequently, depletion of ILCs impaired both pre- and post-immune TI antibody responses. Thus, ILCs integrate stromal and myeloid signals to orchestrate innate-like antibody production at the interface between the immune system and circulatory system.
Assuntos
Formação de Anticorpos , Linfócitos B/imunologia , Linfócitos/imunologia , Plasmócitos/imunologia , Baço/imunologia , Animais , Anticorpos/sangue , Antígenos T-Independentes/imunologia , Proteínas Sanguíneas/imunologia , Moléculas de Adesão Celular , Comunicação Celular/imunologia , Diferenciação Celular , Células Cultivadas , Fator Estimulador de Colônias de Granulócitos e Macrófagos/metabolismo , Humanos , Imunidade Inata , Imunoglobulinas/metabolismo , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos C57BL , Mucoproteínas/metabolismo , Neutrófilos/imunologia , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/metabolismo , Picratos/imunologia , Transdução de Sinais/imunologia , Células Estromais/imunologiaRESUMO
Although maternal antibodies protect newborn babies from infection1,2, little is known about how protective antibodies are induced without prior pathogen exposure. Here we show that neonatal mice that lack the capacity to produce IgG are protected from infection with the enteric pathogen enterotoxigenic Escherichia coli by maternal natural IgG antibodies against the maternal microbiota when antibodies are delivered either across the placenta or through breast milk. By challenging pups that were fostered by either maternal antibody-sufficient or antibody-deficient dams, we found that IgG derived from breast milk was crucial for protection against mucosal disease induced by enterotoxigenic E. coli. IgG also provides protection against systemic infection by E. coli. Pups used the neonatal Fc receptor to transfer IgG from milk into serum. The maternal commensal microbiota can induce antibodies that recognize antigens expressed by enterotoxigenic E. coli and other Enterobacteriaceae species. Induction of maternal antibodies against a commensal Pantoea species confers protection against enterotoxigenic E. coli in pups. This role of the microbiota in eliciting protective antibodies to a specific neonatal pathogen represents an important host defence mechanism against infection in neonates.
Assuntos
Anticorpos/imunologia , Escherichia coli Enterotoxigênica/imunologia , Infecções por Escherichia coli/imunologia , Infecções por Escherichia coli/prevenção & controle , Imunidade Materno-Adquirida/imunologia , Recém-Nascido/imunologia , Microbiota/imunologia , Leite Humano/imunologia , Animais , Anticorpos/sangue , Anticorpos/metabolismo , Aleitamento Materno , Reações Cruzadas/imunologia , Infecções por Escherichia coli/microbiologia , Feminino , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Imunoglobulina G/metabolismo , Masculino , Camundongos , Mães , Pantoea/imunologia , Receptores Fc/imunologia , Receptores Fc/metabolismo , Simbiose/imunologiaRESUMO
Heart transplantation is the only cure for patients with terminal cardiac failure, but the supply of allogeneic donor organs falls far short of the clinical need1-3. Xenotransplantation of genetically modified pig hearts has been discussed as a potential alternative4. Genetically multi-modified pig hearts that lack galactose-α1,3-galactose epitopes (α1,3-galactosyltransferase knockout) and express a human membrane cofactor protein (CD46) and human thrombomodulin have survived for up to 945 days after heterotopic abdominal transplantation in baboons5. This model demonstrated long-term acceptance of discordant xenografts with safe immunosuppression but did not predict their life-supporting function. Despite 25 years of extensive research, the maximum survival of a baboon after heart replacement with a porcine xenograft was only 57 days and this was achieved, to our knowledge, only once6. Here we show that α1,3-galactosyltransferase-knockout pig hearts that express human CD46 and thrombomodulin require non-ischaemic preservation with continuous perfusion and control of post-transplantation growth to ensure long-term orthotopic function of the xenograft in baboons, the most stringent preclinical xenotransplantation model. Consistent life-supporting function of xenografted hearts for up to 195 days is a milestone on the way to clinical cardiac xenotransplantation7.
Assuntos
Transplante de Coração , Xenoenxertos/transplante , Papio , Suínos , Transplante Heterólogo , Animais , Anticorpos/análise , Anticorpos/sangue , Proteínas do Sistema Complemento/análise , Enzimas/sangue , Fibrina/análise , Galactosiltransferases/deficiência , Galactosiltransferases/genética , Xenoenxertos/patologia , Humanos , Fígado/enzimologia , Masculino , Proteína Cofatora de Membrana/genética , Proteína Cofatora de Membrana/metabolismo , Miocárdio/enzimologia , Necrose , Perfusão , Contagem de Plaquetas , Tempo de Protrombina , Trombomodulina/genética , Trombomodulina/metabolismo , Fatores de TempoRESUMO
Secondary non-response to infliximab (IFX) occurs in some patients with rheumatoid arthritis (RA). Although therapeutic drug monitoring (TDM) is a useful tool to optimize IFX therapy, it is unclear whether it can help to identify the risk of secondary non-response. This study aimed to explore the utility of serum levels of IFX or other biomarkers to predict IFX discontinuation owing to secondary non-response. A single-center, retrospective study was conducted using the Kyoto University Rheumatoid Arthritis Management Alliance cohort database between 2011 and 2020. Serum IFX levels were measured using liquid chromatography-tandem mass spectrometry. An electrochemiluminescence assay was used to quantify serum levels of tumor necrosis factor-α and interleukin-6 and detect anti-drug antibodies. Eighty-four out of 310 patients were eligible for this study. The cutoff levels of biomarkers were determined by receiver operating characteristic analysis. IFX persistence was similar between groups stratified using IFX levels, tumor necrosis factor-α levels, interleukin-6 levels, and anti-drug antibodies positivity. The group with lower IFX and higher interleukin-6 levels had the worst therapy persistence (p = 0.017) and the most frequent disease worsening (90.0%, p < 0.001). Evaluating both interleukin-6 and IFX levels, not just IFX alone, enabled us to identify patients at risk of discontinuing IFX treatment. These findings support the utility of measuring IFX and interleukin-6 levels for successful maintenance therapy for RA.
Assuntos
Antirreumáticos , Artrite Reumatoide , Infliximab , Interleucina-6 , Humanos , Anticorpos/sangue , Antirreumáticos/uso terapêutico , Artrite Reumatoide/tratamento farmacológico , Biomarcadores , Infliximab/uso terapêutico , Interleucina-6/sangue , Estudos Retrospectivos , Fator de Necrose Tumoral alfaRESUMO
Toward the goal of increasing the throughput of high-resolution mass characterization of intact antibodies, we developed a RapidFire-mass spectrometry (MS) assay using electrospray ionization. We achieved unprecedented screening throughput as fast as 15 s/sample, which is an order of magnitude improvement over conventional liquid chromatography (LC)-MS approaches. The screening enabled intact mass determination as accurate as 7 ppm with baseline resolution at the glycoform level for intact antibodies. We utilized this assay to characterize and perform relative quantitation of antibody species from 248 samples of 62 different cell line clones at four time points in 2 h using RapidFire-time-of-flight MS screening. The screening enabled selection of clones with the highest purity of bispecific antibody production and the results significantly correlated with conventional LC-MS results. In addition, analyzing antibodies from a complex plasma sample using affinity-RapidFire-MS was also demonstrated and qualified. In summary, the platform affords high-throughput analyses of antibodies, including bispecific antibodies and potential mispaired side products, in cell culture media, or other complex matrices.
Assuntos
Anticorpos Biespecíficos/sangue , Anticorpos/sangue , Ensaios de Triagem em Larga Escala/métodos , Espectrometria de Massas por Ionização por Electrospray/métodos , Anticorpos/isolamento & purificação , Anticorpos Biespecíficos/isolamento & purificação , Linhagem Celular , Cromatografia Líquida/métodos , HumanosRESUMO
One of the main issues of the peculiarities of the immune reactions of the gastrointestinal tract is the mechanisms of ensuring tolerance to food antigens. Concentrations of antibodies to food antigens actually reflect the state of the intestinal mucosa barrier function, and the degree of penetration of antigens into the blood determines the level of immune response to them. The aim of the study was to determine the risk criteria for violation of tolerance to food antigens. Material and methods. The study included the results of a survey and examination of 1334 adults living in the north of the European part of the Russian Federation, including 1100 born in the North, of which 970 were women and 364 were men. The average age of the respondents was 45.5±1.0 years. The comparison group consisted of 344 patients with pathology of the gastrointestinal tract who applied to the medical company "Biocor". The content of immunoglobulins (Ig) G to food antigens, total IgA, cytokines (tumor necrosis factor α, interleukin-6, interleukin-4) in blood serum were determined by enzyme immunoassay. Results. Rural residents often (more than 28%) have elevated concentrations of IgG to potato, river fish, wheat and rye antigens. Urban residents have the most pronounced decrease in tolerance to food antigens of chicken, cod, beef and pork. In healthy individuals, elevated (>100 ME/ml) concentrations of antibodies to meat products are recorded in the range of 11.3-13.9%, to dairy antigens - 11.5-14.1%, cereals - 11.9-13.4%. Slightly less frequently, elevated concentrations of antibodies to fish antigens (7.5-10.1%), vegetables (3.8-7.0%) and fruits (4.9-6.5%) are detected. In inflammatory and oncological diseases of the gastrointestinal tract, the content of antibodies to food antigens increases sharply. On average, the frequency of impaired tolerance to food antigens in patients is 2.7-6.1 times higher than in healthy individuals. Conclusion. Violation of tolerance to food antigens is associated with an increase in blood pro-inflammatory cytokines, mainly interleukin-6. In practically healthy individuals, a decrease in tolerance to food antigens is associated with a deficiency of blood IgA. The risk criteria for violation of the diet or consumption of low-quality foods may be an increase in the frequency of detection of elevated concentrations of antibodies to meat products in 14.6±3.0%, fish - 10.7±2.3%, cereals - 13.7±1.6%, dairy products - 14.8±1.5%, vegetables - 7.8±2.4% and fruits - 6.9±5.8%.
Assuntos
Anticorpos , Antígenos , Alimentos , Tolerância Imunológica , Imunoglobulina A , Interleucina-6 , Feminino , Humanos , Masculino , Citocinas/sangue , Citocinas/imunologia , Grão Comestível , Frutas , Imunoglobulina A/sangue , Imunoglobulina A/imunologia , Interleucina-6/sangue , Interleucina-6/imunologia , Verduras , Adulto , Pessoa de Meia-Idade , Antígenos/sangue , Antígenos/imunologia , Tolerância Imunológica/imunologia , Anticorpos/sangue , Anticorpos/imunologia , Medição de RiscoRESUMO
Neisseria meningitidis serogroup B (MenB) is the leading cause of meningococcal meningitis and sepsis in industrialized countries, with the highest incidence in infants and adolescents. Two recombinant protein vaccines that protect against MenB are now available (i.e. 4CMenB and MenB-fHbp). Both vaccines contain the Factor H Binding Protein (fHbp) antigen, which can bind the Human Factor H (fH), the main negative regulator of the alternative complement pathway, thus enabling bacterial survival in the blood. fHbp is present in meningococcal strains as three main variants which are immunologically distinct. Here we sought to obtain detailed information about the epitopes targeted by anti-fHbp antibodies induced by immunization with the 4CMenB multicomponent vaccine. Thirteen anti-fHbp human monoclonal antibodies (mAbs) were identified in a library of over 100 antibody fragments (Fabs) obtained from three healthy adult volunteers immunized with 4CMenB. Herein, the key cross-reactive mAbs were further characterized for antigen binding affinity, complement-mediated serum bactericidal activity (SBA) and the ability to inhibit binding of fH to live bacteria. For the first time, we identified a subset of anti-fHbp mAbs able to elicit human SBA against strains with all three variants and able to compete with human fH for fHbp binding. We present the crystal structure of fHbp v1.1 complexed with human antibody 4B3. The structure, combined with mutagenesis and binding studies, revealed the critical cross-reactive epitope. The structure also provided the molecular basis of competition for fH binding. These data suggest that the fH binding site on fHbp v1.1 can be accessible to the human immune system upon immunization, enabling elicitation of human mAbs broadly protective against MenB. The novel structural, biochemical and functional data are of great significance because the human vaccine-elicited mAbs are the first reported to inhibit the binding of fH to fHbp, and are bactericidal with human complement. Our studies provide molecular insights into the human immune response to the 4CMenB meningococcal vaccine and fuel the rationale for combined structural, immunological and functional studies when seeking deeper understanding of the mechanisms of action of human vaccines.
Assuntos
Anticorpos/imunologia , Antígenos de Bactérias/metabolismo , Proteínas de Bactérias/metabolismo , Meningite Meningocócica/imunologia , Vacinas Meningocócicas/administração & dosagem , Neisseria meningitidis/imunologia , Adulto , Anticorpos/sangue , Antígenos de Bactérias/imunologia , Proteínas de Bactérias/imunologia , Fator H do Complemento/imunologia , Fator H do Complemento/metabolismo , Humanos , Meningite Meningocócica/metabolismo , Meningite Meningocócica/microbiologia , Meningite Meningocócica/prevenção & controleRESUMO
Prompt diagnostic evaluation of suspected heparin-induced thrombocytopenia (HIT) is critical for guiding initial patient management. We assessed the performance of 3 immunoassays detecting anti-platelet factor 4 (PF4)/heparin antibodies, derived a diagnostic algorithm with a short analytical turnaround time (TAT), and prospectively validated the algorithm. Plasma samples were analyzed by Zymutest-HIA-IgG, HemosIL-AcuStar-HIT-IgG, and ID-H/PF4-PaGIA in retrospective (n = 221) and prospective (n = 305) derivation cohorts. We calculated likelihood ratios of result intervals and cutoff values with 100% negative (NPV) and positive (PPV) predictive values for a positive gold standard functional assay (heparin-induced platelet activation [HIPA]). A diagnostic algorithm was established based on the Bayesian combination of pretest probability and likelihood ratios of first- and second-line immunoassays. Cutoffs with 100% PPV for positive HIPA were >3.0 U/mL (HemosIL-AcuStar-HIT-IgG) and titer ≥16 (ID-H/PF4-PaGIA); cutoffs with 100% NPV were <0.13 U/mL and ≤1, respectively. During the prospective validation of the derived algorithm (n = 687), HemosIL-AcuStar-HIT-IgG was used as unique testing in 566 (82.4%) of 687 cases (analytical TAT, 30 minutes). In 121 (17.6%) of 687 unresolved cases, ID-H/PF4-PaGIA was used as second-line testing (additional TAT, 30 minutes). The algorithm accurately predicted HIT in 51 (7.4%) of 687 patients and excluded it in 604 (87.9%) of 687 patients, leaving only 20 (2.9%) cases unresolved. We also identified 12 (1.7%) of 687 positive predictions not confirmed by HIPA: 10 patients with probable HIT despite negative HIPA and 2 possible false-positive algorithm predictions. The combination of pretest probability with first- and second-line immunoassays for anti-PF4/heparin antibodies is accurate for ruling in or out HIT in ≥95% of cases within 60 minutes. This diagnostic approach improves initial management of patients with suspected HIT.
Assuntos
Anticorpos/sangue , Anticoagulantes/efeitos adversos , Heparina/efeitos adversos , Trombocitopenia/induzido quimicamente , Trombocitopenia/diagnóstico , Idoso , Anticorpos/imunologia , Anticoagulantes/imunologia , Teorema de Bayes , Ensaio de Imunoadsorção Enzimática/economia , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Heparina/imunologia , Humanos , Imunoensaio/economia , Imunoensaio/métodos , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Masculino , Fator Plaquetário 4/imunologia , Estudos Prospectivos , Estudos Retrospectivos , Sensibilidade e Especificidade , Trombocitopenia/sangue , Fatores de TempoRESUMO
OBJECTIVE: To describe onset clinical features predicting time to first relapse and time to long-term visual, motor and cognitive disabilities in paediatric-onset aquaporin-4 antibody (AQP4-IgG) neuromyelitis optica spectrum disorders (NMOSDs). METHODS: In this retrospective UK multicentre cohort study, we recorded clinical data of paediatric-onset AQP4-IgG NMOSD. Univariate and exploratory multivariable Cox proportional hazard models were used to identify long-term predictors of permanent visual disability, Expanded Disability Status Scale (EDSS) score of 4 and cognitive impairment. RESULTS: We included 49 paediatric-onset AQP4-IgG patients (38.8% white, 34.7% black, 20.4% Asians and 6.1% mixed), mean onset age of 12±4.1 years, and 87.7% were female. Multifocal onset presentation occurred in 26.5% of patients, and optic nerve (47%), area postrema/brainstem (48.9%) and encephalon (28.6%) were the most involved areas. Overall, 52.3% of children had their first relapse within 1 year from disease onset. Children with onset age <12 years were more likely to have an earlier first relapse (p=0.030), despite showing no difference in time to immunosuppression compared with those aged 12-18 years at onset. At the cohort median disease duration of 79 months, 34.3% had developed permanent visual disability, 20.7% EDSS score 4 and 25.8% cognitive impairment. Visual disability was associated with white race (p=0.032) and optic neuritis presentations (p=0.002). Cognitive impairment was predicted by cerebral syndrome presentations (p=0.048), particularly if resistant to steroids (p=0.034). CONCLUSIONS: Age at onset, race, onset symptoms and resistance to acute therapy at onset attack predict first relapse and long-term disabilities. The recognition of these predictors may help to power future paediatric clinical trials and to direct early therapeutic decisions in AQP4-IgG NMOSD.
Assuntos
Aquaporina 4 , Pessoas com Deficiência/estatística & dados numéricos , Neuromielite Óptica/diagnóstico , Adolescente , Adulto , Idade de Início , Anticorpos/sangue , Povo Asiático/estatística & dados numéricos , População Negra/estatística & dados numéricos , Encéfalo/patologia , Criança , Estudos de Coortes , Avaliação da Deficiência , Progressão da Doença , Feminino , Humanos , Imunoglobulina G/uso terapêutico , Masculino , Pessoa de Meia-Idade , Nervo Óptico/patologia , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Reino Unido , População Branca/estatística & dados numéricos , Adulto JovemRESUMO
MOTIVATION: A comprehensive characterization of the humoral response towards a specific antigen requires quantification of the B-cell receptor repertoire by next-generation sequencing (BCR-Seq), as well as the analysis of serum antibodies against this antigen, using proteomics. The proteomic analysis is challenging since it necessitates the mapping of antigen-specific peptides to individual B-cell clones. RESULTS: The PASA web server provides a robust computational platform for the analysis and integration of data obtained from proteomics of serum antibodies. PASA maps peptides derived from antibodies raised against a specific antigen to corresponding antibody sequences. It then analyzes and integrates proteomics and BCR-Seq data, thus providing a comprehensive characterization of the humoral response. The PASA web server is freely available at https://pasa.tau.ac.il and open to all users without a login requirement.
Assuntos
Anticorpos , Internet , Proteômica/métodos , Software , Animais , Anticorpos/sangue , Anticorpos/imunologia , Antígenos/imunologia , Linfócitos B/imunologia , Bases de Dados de Proteínas , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , CamundongosRESUMO
Heparin-induced thrombocytopenia is an immune-mediated disorder caused by antibodies that recognize complexes of platelet factor 4 and heparin. Thrombosis is a central and unpredictable feature of this syndrome. Despite optimal management, disease morbidity and mortality from thrombosis remain high. The hypercoagulable state in heparin-induced thrombocytopenia is biologically distinct from other thrombophilic disorders in that clinical complications are directly attributable to circulating ultra-large immune complexes. In some individuals, ultra-large immune complexes elicit unchecked cellular procoagulant responses that culminate in thrombosis. To date, the clinical and biologic risk factors associated with thrombotic risk in heparin-induced thrombocytopenia remain elusive. This review will summarize our current understanding of thrombosis in heparin-induced thrombocytopenia with attention to its clinical features, cellular mechanisms, and its management.
Assuntos
Anticorpos/sangue , Anticoagulantes/administração & dosagem , Coagulação Sanguínea , Heparina/efeitos adversos , Fator Plaquetário 4/imunologia , Trombocitopenia/induzido quimicamente , Trombose/induzido quimicamente , Animais , Anticoagulantes/imunologia , Antitrombinas/uso terapêutico , Coagulação Sanguínea/efeitos dos fármacos , Inibidores do Fator Xa/uso terapêutico , Heparina/imunologia , Humanos , Fatores de Risco , Trombocitopenia/sangue , Trombocitopenia/tratamento farmacológico , Trombocitopenia/imunologia , Trombose/sangue , Trombose/tratamento farmacológico , Trombose/imunologiaRESUMO
[Figure: see text].
Assuntos
Aorta/efeitos dos fármacos , Doenças da Aorta/prevenção & controle , Aterosclerose/prevenção & controle , Colesterol/metabolismo , Proteínas de Choque Térmico/administração & dosagem , Chaperonas Moleculares/administração & dosagem , Pró-Proteína Convertase 9/metabolismo , Receptores de LDL/metabolismo , Vacinas Sintéticas/administração & dosagem , Idoso , Idoso de 80 Anos ou mais , Animais , Anticorpos/sangue , Aorta/enzimologia , Aorta/imunologia , Aorta/patologia , Doenças da Aorta/enzimologia , Doenças da Aorta/imunologia , Doenças da Aorta/patologia , Aterosclerose/enzimologia , Aterosclerose/imunologia , Aterosclerose/patologia , Estudos de Casos e Controles , Modelos Animais de Doenças , Feminino , Proteínas de Choque Térmico/imunologia , Proteínas de Choque Térmico/metabolismo , Células Hep G2 , Humanos , Imunogenicidade da Vacina , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout para ApoE , Pessoa de Meia-Idade , Chaperonas Moleculares/imunologia , Chaperonas Moleculares/metabolismo , Placa Aterosclerótica , Receptores de LDL/genética , Vacinação , Vacinas Sintéticas/imunologiaRESUMO
The aim of this study was to establish a time-resolved fluorescent immunoassay (TRFIA) for the detection of serum Galectin-3 (Gal-3) and apply this method to evaluate the clinical significance of serum Gal-3 in predicting Idiopathic Membranous Nephropathy (IMN) progression. The Gal-3-TRFIA was established using the double antibody sandwich method, with the capture antibodies coated on a 96-well microplate and the detection antibodies chelated with Europium (III) (Eu3+). Serum Gal-3 was detected in 81 patients with IMN and 123 healthy controls to further evaluate the value of the Gal-3 in staging of IMN. The sensitivity of the Gal-3-TRFIA assay was 0.85 ng/mL, and the detection range was 0.85-1000 ng/mL. The Gal-3 intra-batch and inter-batch coefficients of variation were 3.45% and 5.12%, respectively. The correlation coefficient (R) between the Gal-3-TRFIA assay and commercially available enzyme-linked immunosorbent assay kits was 0.83. The serum Gal-3 concentration was higher in patients with IMN (65.57 ± 55.90 ng/mL) compared to healthy controls (16.29 ± 9.91 ng/mL, P < 0.0001). In this study, a wide detection range Gal-3-TRFIA assay was developed using lanthanide (Eu3+) chelates for the detection of Gal-3 concentrations in serum. Gal-3 concentration is elevated in patients with IMN.
Assuntos
Fluorimunoensaio/métodos , Galectina 3/sangue , Glomerulonefrite Membranosa/sangue , Glomerulonefrite Membranosa/diagnóstico , Anticorpos/sangue , Progressão da Doença , Ensaio de Imunoadsorção Enzimática , Galectina 3/imunologia , Humanos , Estudos Prospectivos , Sensibilidade e Especificidade , Fatores de TempoRESUMO
BACKGROUND: The role of angiotensin II type 1 receptor antibodies (AT1R-Ab) in pediatric renal transplantation is unclear. Here, we evaluated pre-transplant AT1R-Ab on transplant outcomes in the first 5 years. Secondary analysis compared pre-transplant AT1R-Ab levels by age. METHODS: Thirty-six patients, 2-20 years old, were divided into two groups: pre-transplant AT1R-Ab- (<17 U/ml; n = 18) and pre-transplant AT1R-Ab+ (≥17 U/ml; n = 18). eGFR was determined at 6-month, 1-, 2-, and 4-year post-transplant. Allograft biopsies were performed in the setting of strong HLA-DSA (MFI > 10 000), AT1R-Ab ≥17 U/ml, and/or elevated creatinine. RESULTS: Mean age in pre-transplant AT1R-Ab- was 13.3 years vs. 11.0 in pre-transplant AT1R-Ab+ (p = 0.16). At 6 months, mean eGFR was 111.3 ml/min/1.73 m2 in pre-transplant AT1R-Ab- vs. 100.2 in pre-transplant AT1R-Ab + at 1 year, 103.6 ml/min/1.73 m2 vs. 100.5; at 2 years, 98.9 ml/min/1.73 m2 vs. and 93.7; at 4 years, 72.6 ml/min/1.73 m2 vs. 80.9. 11/36 patients had acute rejection (6 in pre-transplant AT1R-Ab-, 5 in pre-transplant AT1R-Ab + ). There was no difference in rejection rates. All 6 subjects with de novo HLA-DSA and AT1R-Ab ≥17 U/ml at the time of biopsy experienced rejection. Mean age in those with the AT1R-Ab ≥40 U/ml was 10.0 years vs. 13.2 in those <40 U/ml (p = 0.07). CONCLUSION: In our small cohort, pre-transplant AT1R-Ab ≥17 U/ml was not associated with reduced graft function or rejection. The pathogenicity of pre-transplant AT1R-Ab in pediatric kidney transplantation requires further investigation.
Assuntos
Anticorpos , Rejeição de Enxerto , Transplante de Rim , Receptor Tipo 1 de Angiotensina , Adolescente , Adulto , Criança , Pré-Escolar , Humanos , Adulto Jovem , Anticorpos/sangue , Estudos de Coortes , Rejeição de Enxerto/sangue , Rejeição de Enxerto/imunologia , Antígenos HLA/imunologia , Rim/patologia , Receptor Tipo 1 de Angiotensina/imunologiaRESUMO
BACKGROUND: There is a need to assess the long-term outcomes of survivors of critical illness from COVID-19. METHODS: Ninety-two survivors of critical illness from COVID-19 from four hospitals in Hubei Province, China participated in this prospective cohort study. Multiple characteristics, including lung function (lung volumes, diffusing capacity for carbon monoxide, chest computed tomography scores, and walking capacity); immune status (SARS-CoV-2-neutralising antibody and all subtypes of immunoglobulin (Ig) G against SARS-CoV-2, immune cells in response to ex vivo antigen peptide stimuli, and lymphocyte count and its subtypes); liver, coagulation, and kidney functions; quality of life; cognitive function; and mental status, were assessed after 3, 6, and 12 months of follow-up. RESULTS: Amongst the 92 enrolled survivors, 72 (78%) patients required mechanical ventilation. At 12 months, the predicted percentage diffusing capacity of lung for carbon monoxide was 82% (inter-quartile range [IQR]: 76-97%) with a residual volume of 77 (64-88)%. Other lung function parameters and the 6-min walk test improved gradually over time and were almost back to normal by 12 months. The titres of IgG and neutralising antibody to COVID-19 remained high at 12 months compared with those of controls who were not infected with COVID-19, although IgG titres decreased significantly from 34.0 (IQR: 23.8-74.3) to 15.0 (5.8-24.3) AU ml-1 (P<0.001), whereas neutralising antibodies decreased from 29.99 (IQR: 19.43-53.93) AU ml-1 at 6 months to 19.75 (13.1-29.8) AU ml-1 (P<0.001) at 12 months. In general, liver, kidney, physical, and mental functions also improved over time. CONCLUSIONS: Survivors of critical illness from COVID-19 show some persistent long-term impairments in lung function. However, a majority of these tests were normal by 12 months. These patients still had detectable levels of neutralising antibodies against SARS-CoV-2 and all types of IgG at 12 months, but the levels had declined over this time period. CLINICAL TRIAL REGISTRATION: None.
Assuntos
Anticorpos/sangue , COVID-19/diagnóstico , COVID-19/imunologia , Sobreviventes , Idoso , Anticorpos Neutralizantes/sangue , COVID-19/sangue , China , Estado Terminal , Citocinas/sangue , Feminino , Humanos , Rim/fisiopatologia , Fígado/fisiopatologia , Pulmão/diagnóstico por imagem , Pulmão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Prospectivos , Qualidade de Vida , Testes de Função Respiratória , SARS-CoV-2/imunologia , Tomografia Computadorizada por Raios X , Teste de CaminhadaRESUMO
Much of our knowledge of the drivers of immune variation, and how these responses vary over time, comes from humans, domesticated livestock or laboratory organisms. While the genetic basis of variation in immune responses have been investigated in these systems, there is a poor understanding of how genetic variation influences immunity in natural, untreated populations living in complex environments. Here, we examine the genetic architecture of variation in immune traits in the Soay sheep of St Kilda, an unmanaged population of sheep infected with strongyle gastrointestinal nematodes. We assayed IgA, IgE and IgG antibodies against the prevalent nematode Teladorsagia circumcincta in the blood plasma of > 3,000 sheep collected over 26 years. Antibody levels were significantly heritable (h2 = 0.21 to 0.57) and highly stable over an individual's lifespan. IgA levels were strongly associated with a region on chromosome 24 explaining 21.1% and 24.5% of heritable variation in lambs and adults, respectively. This region was adjacent to two candidate loci, Class II Major Histocompatibility Complex Transactivator (CIITA) and C-Type Lectin Domain Containing 16A (CLEC16A). Lamb IgA levels were also associated with the immunoglobulin heavy constant loci (IGH) complex, and adult IgE levels and lamb IgA and IgG levels were associated with the major histocompatibility complex (MHC). This study provides evidence of high heritability of a complex immunological trait under natural conditions and provides the first evidence from a genome-wide study that large effect genes located outside the MHC region exist for immune traits in the wild.
Assuntos
Animais Selvagens/imunologia , Imunidade Inata , Ovinos/imunologia , Infecções por Strongylida/imunologia , Animais , Animais Selvagens/sangue , Anticorpos/sangue , Anticorpos/imunologia , Helmintos/imunologia , Helmintos/patogenicidade , Imunoglobulina A/sangue , Imunoglobulina A/imunologia , Imunoglobulina E/sangue , Imunoglobulina E/imunologia , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Ovinos/sangue , Infecções por Strongylida/sangueRESUMO
BACKGROUND: Circulating anti-HLA donor-specific antibodies (HLA-DSA) are often absent in kidney transplant recipients with microvascular inflammation (MVI). Missing self, the inability of donor endothelial cells to provide HLA I-mediated signals to inhibitory killer cell Ig-like receptors (KIRs) on recipient natural killer cells, can cause endothelial damage in vitro, and has been associated with HLA-DSA-negative MVI. However, missing self's clinical importance as a nonhumoral trigger of allograft rejection remains unclear. METHODS: In a population-based study of 924 consecutive kidney transplantations between March 2004 and February 2013, we performed high-resolution donor and recipient HLA typing and recipient KIR genotyping. Missing self was defined as the absence of A3/A11, Bw4, C1, or C2 donor genotype, with the presence of the corresponding educated recipient inhibitory KIR gene. RESULTS: We identified missing self in 399 of 924 transplantations. Co-occurrence of missing self types had an additive effect in increasing MVI risk, with a threshold at two concurrent types (hazard ratio [HR], 1.78; 95% confidence interval [95% CI], 1.26 to 2.53), independent of HLA-DSA (HR, 5.65; 95% CI, 4.01 to 7.96). Missing self and lesions of cellular rejection were not associated. No HLA-DSAs were detectable in 146 of 222 recipients with MVI; 28 of the 146 had at least two missing self types. Missing self associated with transplant glomerulopathy after MVI (HR, 2.51; 95% CI, 1.12 to 5.62), although allograft survival was better than with HLA-DSA-associated MVI. CONCLUSION: Missing self specifically and cumulatively increases MVI risk after kidney transplantation, independent of HLA-DSA. Systematic evaluation of missing self improves understanding of HLA-DSA-negative MVI and might be relevant for improved diagnostic classification and patient risk stratification.
Assuntos
Rejeição de Enxerto/imunologia , Antígenos HLA/genética , Antígenos HLA/imunologia , Células Matadoras Naturais/imunologia , Receptores KIR/genética , Vasculite/genética , Adulto , Idoso , Anticorpos/sangue , Feminino , Genótipo , Sobrevivência de Enxerto , Antígeno HLA-A11/genética , Antígeno HLA-A11/imunologia , Antígeno HLA-A3/genética , Antígeno HLA-A3/imunologia , Antígenos HLA-B/genética , Antígenos HLA-B/imunologia , Antígenos HLA-C/genética , Antígenos HLA-C/imunologia , Teste de Histocompatibilidade , Humanos , Transplante de Rim , Masculino , Microvasos , Pessoa de Meia-Idade , Receptores KIR2DL2/genética , Receptores KIR2DL3/genética , Doadores de Tecidos , Transplantados , Vasculite/complicaçõesRESUMO
BACKGROUND AND OBJECTIVES: Adverse environmental factors in tunnels increase the occurrence of respiratory and intestinal inflammatory disease, which is seriously harmful to worker health. It is reported that medium-chain triglycerides (MCT) can improve immune status and alter the gut microflora. This study investigates MCT effects on immune status and gut microbiota among tunnel workers. METHODS AND STUDY DESIGN: Forty-five workers were randomly divided into an MCT group (n=30) and control group (n=15), where they ingested MCT-milk or a placebo milk for 12 weeks, respectively. The primary outcome measure was the incidence of respiratory infection and diarrhea. Secondary outcomes were changes in serum immune-related markers and changes in gut microbiota. RESULTS: The incidence of diarrhea in MCT group was significantly decreased after 4 weeks (p<0.01), with no significant differences in the control group. MCT reduced the level of pro-inflammatory cytokines (TNF-α, CRP, and IL-6) and enhanced the anti-inflammatory cytokines (IL-10, C3, C4, IgA, IgG, and IgM), respectively (p<0.01). The Chao index was reduced (p<0.01) and microbiota composition changed significantly after 12 weeks of MCT intervention. MCT reduced the abundance of Bacteroides, Roseburia, Ruminococcus_1, Lachnospira and increased that of Blautia and Fusicatenibacter at the genus level (p<0.01). CONCLUSIONS: The consumption of MCT reduces diarrhea occurrence and improves serum immune profiles together with gut microbiomics in tunnel workers.
Assuntos
Diarreia , Microbioma Gastrointestinal , Enteropatias , Triglicerídeos , Anticorpos/sangue , China , Citocinas/sangue , Diarreia/terapia , Humanos , Inflamação/terapia , Enteropatias/terapia , Doenças Profissionais/terapia , Triglicerídeos/administração & dosagemRESUMO
ABSTRACT: Antibodies are a fundamental tool to fight infections but are intrinsically built as a double-edged sword. One side recognizes the microbial antigen, and the other gives a call to arms to fight infection by recruiting immune cells and triggering inflammation. A balanced immune response must combine a potent neutralizing antibody and a swift disposal of the invading agent by innate immune cells with the least tissue damage possible. The longer the immune system takes to control the infection, the higher the possibility for a self-sustaining inflammatory process with potentially fatal consequences for the host. In addition to quantity, the quality of antibodies also matters, because posttranslational modifications altering the N-glycan composition in Fc fractions may help tilt the balance to the effector side, by modifying their affinity for Fc receptors in immune cells. The COVID-19 pandemic has provided a wealth of data bolstering our understanding of the rules governing the production of protective and nonprotective antibodies. Also, it has broadened our understanding of the role of viruses in triggering autoimmunity and inflammation, and widened our knowledge of the different mechanisms that can be activated by viral infection and lead to autoantibody production, inflammation, and progressive tissue damage. In addition, the COVID-19 infection has contributed a great deal to our comprehension of the role of antibodies in the causation of cytokine storms and systemic inflammatory response syndrome, also seen in patients with systemic autoimmune diseases.