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Severe defects in human IFNγ immunity predispose individuals to both Bacillus Calmette-Guérin disease and tuberculosis, whereas milder defects predispose only to tuberculosis1. Here we report two adults with recurrent pulmonary tuberculosis who are homozygous for a private loss-of-function TNF variant. Neither has any other clinical phenotype and both mount normal clinical and biological inflammatory responses. Their leukocytes, including monocytes and monocyte-derived macrophages (MDMs) do not produce TNF, even after stimulation with IFNγ. Blood leukocyte subset development is normal in these patients. However, an impairment in the respiratory burst was observed in granulocyte-macrophage colony-stimulating factor (GM-CSF)-matured MDMs and alveolar macrophage-like (AML) cells2 from both patients with TNF deficiency, TNF- or TNFR1-deficient induced pluripotent stem (iPS)-cell-derived GM-CSF-matured macrophages, and healthy control MDMs and AML cells differentiated with TNF blockers in vitro, and in lung macrophages treated with TNF blockers ex vivo. The stimulation of TNF-deficient iPS-cell-derived macrophages with TNF rescued the respiratory burst. These findings contrast with those for patients with inherited complete deficiency of the respiratory burst across all phagocytes, who are prone to multiple infections, including both Bacillus Calmette-Guérin disease and tuberculosis3. Human TNF is required for respiratory-burst-dependent immunity to Mycobacterium tuberculosis in macrophages but is surprisingly redundant otherwise, including for inflammation and immunity to weakly virulent mycobacteria and many other infectious agents.
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BACKGROUND: Cryptococcosis is a life-threatening disease caused by Cryptococcus neoformans or C. gattii. Neutralizing autoantibodies (auto-Abs) against granulocyte-macrophage colony-stimulating factor (GM-CSF) in otherwise healthy adults with cryptococcal meningitis have been described since 2013. We searched for neutralizing auto-Abs in sera collected from Colombian patients with non-HIV-associated cryptococcosis in a retrospective national cohort from 1997 to 2016. METHODS: We reviewed clinical and laboratory records and assessed the presence of neutralizing auto-Abs against GM-CSF in 30 HIV negative adults with cryptococcosis (13 caused by C. gattii and 17 caused by C. neoformans). RESULTS: We detected neutralizing auto-Abs against GM-CSF in the sera of 10 out of 13 (77%) patients infected with C. gattii and one out of 17 (6%) patients infected with C. neoformans. CONCLUSIONS: We report eleven Colombian patients diagnosed with cryptococcosis who had auto-Abs that neutralize GM-CSF. Among these patients, ten were infected with C. gattii and only one with C. neoformans.
Assuntos
Anticorpos Neutralizantes , Autoanticorpos , Criptococose , Cryptococcus gattii , Cryptococcus neoformans , Fator Estimulador de Colônias de Granulócitos e Macrófagos , Humanos , Fator Estimulador de Colônias de Granulócitos e Macrófagos/imunologia , Autoanticorpos/sangue , Autoanticorpos/imunologia , Masculino , Colômbia , Feminino , Adulto , Cryptococcus gattii/imunologia , Pessoa de Meia-Idade , Cryptococcus neoformans/imunologia , Criptococose/imunologia , Criptococose/diagnóstico , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/imunologia , Estudos Retrospectivos , Soronegatividade para HIV/imunologia , Adulto Jovem , IdosoRESUMO
BACKGROUND: Cryptococcosis is a potentially life-threatening fungal disease caused by encapsulated yeasts of the genus Cryptococcus, mostly C. neoformans or C. gattii. Cryptococcal meningitis is the most frequent clinical manifestation in humans. Neutralizing autoantibodies (auto-Abs) against granulocyte-macrophage colony-stimulating factor (GM-CSF) have recently been discovered in otherwise healthy adult patients with cryptococcal meningitis, mostly caused by C. gattii. We hypothesized that three Colombian patients with cryptococcal meningitis caused by C. neoformans in two of them would carry high plasma levels of neutralizing auto-Abs against GM-CSF. METHODS: We reviewed medical and laboratory records, performed immunological evaluations, and tested for anti-cytokine auto-Abs three previously healthy HIV-negative adults with disseminated cryptococcosis. RESULTS: Peripheral blood leukocyte subset levels and serum immunoglobulin concentrations were within the normal ranges. We detected high levels of neutralizing auto-Abs against GM-CSF in the plasma of all three patients. CONCLUSIONS: We report three Colombian patients with disseminated cryptococcosis associated with neutralizing auto-Abs against GM-CSF. Further studies should evaluate the genetic contribution to anti-GM-CSF autoantibody production and the role of the GM-CSF signaling pathway in the immune response to Cryptococcus spp.
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Criptococose , Cryptococcus neoformans , Meningite Criptocócica , Adulto , Humanos , Fator Estimulador de Colônias de Granulócitos e Macrófagos , Meningite Criptocócica/diagnóstico , Autoanticorpos , Colômbia , Criptococose/diagnósticoRESUMO
Germline mutations in CYBB, the human gene encoding the gp91(phox) subunit of the phagocyte NADPH oxidase, impair the respiratory burst of all types of phagocytes and result in X-linked chronic granulomatous disease (CGD). We report here two kindreds in which otherwise healthy male adults developed X-linked recessive Mendelian susceptibility to mycobacterial disease (MSMD) syndromes. These patients had previously unknown mutations in CYBB that resulted in an impaired respiratory burst in monocyte-derived macrophages but not in monocytes or granulocytes. The macrophage-specific functional consequences of the germline mutation resulted from cell-specific impairment in the assembly of the NADPH oxidase. This 'experiment of nature' indicates that CYBB is associated with MSMD and demonstrates that the respiratory burst in human macrophages is a crucial mechanism for protective immunity to tuberculous mycobacteria.
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Genes Ligados ao Cromossomo X , Predisposição Genética para Doença , Macrófagos/imunologia , Glicoproteínas de Membrana/genética , NADPH Oxidases/genética , Tuberculose/genética , Animais , Células CHO , Cricetinae , Cricetulus , Humanos , Masculino , Mutação , NADPH Oxidase 2 , NADPH Oxidases/imunologiaRESUMO
Phagocyte NADPH oxidase plays a key role in pathogen clearance via reactive oxygen species (ROS) production. Defects in oxidase function result in chronic granulomatous disease with hallmark recurrent microbial infections and inflammation. The oxidase's role in the adaptive immune response is not well understood. Class II presentation of cytoplasmic and exogenous Ag to CD4(+) T cells was impaired in human B cells with reduced oxidase p40(phox) subunit expression. Naturally arising mutations, which compromise p40(phox) function in a chronic granulomatous disease patient, also perturbed class II Ag presentation and intracellular ROS production. Reconstitution of patient B cells with a wild-type, but not a mutant, p40(phox) allele restored exogenous Ag presentation and intracellular ROS generation. Remarkably, class II presentation of epitopes from membrane Ag was robust in p40(phox)-deficient B cells. These studies reveal a role for NADPH oxidase and p40(phox) in skewing epitope selection and T cell recognition of self Ag.
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Apresentação de Antígeno/imunologia , Subpopulações de Linfócitos B/imunologia , Subpopulações de Linfócitos B/metabolismo , Antígenos HLA-DR/metabolismo , NADPH Oxidases/fisiologia , Apresentação de Antígeno/genética , Subpopulações de Linfócitos B/enzimologia , Linhagem Celular Transformada , Humanos , Líquido Intracelular/enzimologia , Líquido Intracelular/imunologia , Líquido Intracelular/metabolismo , Ativação Linfocitária/genética , Ativação Linfocitária/imunologia , Fosfoproteínas/biossíntese , Fosfoproteínas/deficiência , Fosfoproteínas/genética , Espécies Reativas de Oxigênio/metabolismo , Regulação para Cima/genética , Regulação para Cima/imunologiaRESUMO
Background: Cryptococcosis is a life-threatening disease caused by Cryptococcus neoformans or C. gattii. Autoantibodies (auto-Abs) neutralizing granulocyte-macrophage colony-stimulating factor (GM-CSF) in otherwise healthy adults with cryptococcal meningitis have been described since 2013. We searched for neutralizing auto-Abs in sera from Colombian patients with non-HIV related cryptococcosis in a retrospective national cohort collected from 1997 to 2016. Methods: We reviewed clinical and laboratory records and assessed the presence of neutralizing auto-Abs in 30 HIV (-) adults presenting cryptococcosis (13 by C. gattii, and 17 by C. neoformans). Results: We detected auto-Abs neutralizing GM-CSF in the plasma of 9 out of 13 (69%) patients infected with C. gattii and 1 out of 17 (6%) patients with C. neoformans. Conclusions: We report ten Colombian patients with cryptococcosis due to auto-Abs neutralizing GM-CSF. Nine of the ten patients were infected with C. gattii, and only one with C. neoformans.
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Multisystem inflammatory syndrome in children (MIS-C) is a rare and severe condition that follows benign COVID-19. We report autosomal recessive deficiencies of OAS1, OAS2, or RNASEL in five unrelated children with MIS-C. The cytosolic double-stranded RNA (dsRNA)-sensing OAS1 and OAS2 generate 2'-5'-linked oligoadenylates (2-5A) that activate the single-stranded RNA-degrading ribonuclease L (RNase L). Monocytic cell lines and primary myeloid cells with OAS1, OAS2, or RNase L deficiencies produce excessive amounts of inflammatory cytokines upon dsRNA or severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) stimulation. Exogenous 2-5A suppresses cytokine production in OAS1-deficient but not RNase L-deficient cells. Cytokine production in RNase L-deficient cells is impaired by MDA5 or RIG-I deficiency and abolished by mitochondrial antiviral-signaling protein (MAVS) deficiency. Recessive OAS-RNase L deficiencies in these patients unleash the production of SARS-CoV-2-triggered, MAVS-mediated inflammatory cytokines by mononuclear phagocytes, thereby underlying MIS-C.
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COVID-19 , Citocinas , Endorribonucleases , SARS-CoV-2 , Síndrome de Resposta Inflamatória Sistêmica , Criança , Humanos , COVID-19/imunologia , Citocinas/genética , Citocinas/imunologia , Endorribonucleases/genética , Endorribonucleases/metabolismo , RNA de Cadeia Dupla , SARS-CoV-2/genética , Síndrome de Resposta Inflamatória Sistêmica/genéticaRESUMO
Chronic granulomatous disease (CGD), an immunodeficiency with recurrent pyogenic infections and granulomatous inflammation, results from loss of phagocyte superoxide production by recessive mutations in any 1 of 4 genes encoding subunits of the phagocyte NADPH oxidase. These include gp91(phox) and p22(phox), which form the membrane-integrated flavocytochrome b, and cytosolic subunits p47(phox) and p67(phox). A fifth subunit, p40(phox), plays an important role in phagocytosis-induced superoxide production via a phox homology (PX) domain that binds to phosphatidylinositol 3-phosphate (PtdIns(3)P). We report the first case of autosomal recessive mutations in NCF4, the gene encoding p40(phox), in a boy who presented with granulomatous colitis. His neutrophils showed a substantial defect in intracellular superoxide production during phagocytosis, whereas extracellular release of superoxide elicited by phorbol ester or formyl-methionyl-leucyl-phenylalanine (fMLF) was unaffected. Genetic analysis of NCF4 showed compound heterozygosity for a frameshift mutation with premature stop codon and a missense mutation predicting a R105Q substitution in the PX domain. Parents and a sibling were healthy heterozygous carriers. p40(phox)R105Q lacked binding to PtdIns(3)P and failed to reconstitute phagocytosis-induced oxidase activity in p40(phox)-deficient granulocytes, with premature loss of p40(phox)R105Q from phagosomes. Thus, p40(phox) binding to PtdIns(3)P is essential for phagocytosis-induced oxidant production in human neutrophils and its absence can be associated with disease.
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Códon de Terminação , Genes Recessivos , Doenças Genéticas Inatas/enzimologia , Doenças Genéticas Inatas/genética , Doença Granulomatosa Crônica/enzimologia , Doença Granulomatosa Crônica/genética , Mutação de Sentido Incorreto , NADPH Oxidases/genética , NADPH Oxidases/metabolismo , Neutrófilos/enzimologia , Adulto , Substituição de Aminoácidos , Carcinógenos , Linhagem Celular Tumoral , Criança , Análise Mutacional de DNA , Feminino , Doença Granulomatosa Crônica/patologia , Heterozigoto , Humanos , Masculino , N-Formilmetionina Leucil-Fenilalanina/farmacologia , Neutrófilos/patologia , Fagocitose/genética , Ésteres de Forbol , Fosfatos de Fosfatidilinositol , Superóxidos/metabolismoAssuntos
Neutrófilos/metabolismo , Fosfatos de Fosfatidilinositol/metabolismo , Fosfoproteínas/fisiologia , Explosão Respiratória/fisiologia , Superóxidos/metabolismo , Animais , Aspergilose/metabolismo , Aspergilose/microbiologia , Aspergilose/patologia , Aspergillus fumigatus , Humanos , Camundongos , Mutação/genética , NADPH Oxidases/metabolismo , Neutrófilos/microbiologia , Neutrófilos/patologiaRESUMO
Background Abdominal obesity (AO) is linked to inflammation and insulin resistance (IR). However, there is limited information on whether preschoolers with AO present these risk factors. We evaluated the association between AO and cardiovascular risk factors in preschoolers. Methods We enrolled 232 children (2-5 years), of whom 50% had AO. Serum total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-c), high-density lipoprotein-cholesterol (HDL-c), triglycerides (TG), apolipoprotein B (Apo-B) and apolipoprotein A-1 (Apo-A1), glucose, insulin, high-sensitivity C-reactive protein (hs-CRP), tumor necrosis factor-alpha (TNF-α), interleukin (IL)-6, IL-1ß, monocyte chemoattractant protein (MCP-1/CCL2), leptin, adiponectin, vascular cell adhesion molecule (VCAM-1/CD106) and intercellular adhesion molecule (ICAM-1/CD54) were measured. The homeostatic model assessment of IR (HOMA-IR) was calculated. We analyzed these variables according to the presence of AO and other metabolic syndrome (MetS) components. Results A total of 75.8% of children with AO had one or more risk factors for MetS. Children with AO had significantly higher body mass indexes (BMIs), insulin, HOMA-IR, TG, very low-density lipoprotein-cholesterol (VLDL-c) and TC/HDL-c ratio and lower HDL-c, compared to children without AO; but there were no differences in inflammatory markers. After adjusting for BMI, sex and age, the differences between groups were not significant for any variable. Waist circumference (WC) was correlated with insulin (r=0.547; p<0.001), TG (r=0.207; p=0.001), ICAM-1 (r=0.213; p=0.039), hs-CRP (r=0.189; p=0.015) and glucose (r=0.187; p=0.004). After adjusting for BMI, age and sex, AO plus one MetS component contributed to individual variation in glucose, insulin, HOMA-IR and TG. Conclusions AO in preschool children is associated with greater IR and atherogenic lipid profiles, although these findings seem to be more related to general obesity than just central obesity. In addition, our data suggest that IR may precede the elevation of systemic cytokines in obese children, unlike findings in adults. More studies in pediatric populations are needed to elucidate these associations.
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Doenças Cardiovasculares/sangue , Resistência à Insulina/fisiologia , Síndrome Metabólica/sangue , Obesidade Abdominal/sangue , Apolipoproteínas/sangue , Biomarcadores/sangue , Glicemia , Índice de Massa Corporal , Doenças Cardiovasculares/etiologia , Pré-Escolar , Colesterol/sangue , Colômbia , Estudos Transversais , Citocinas/sangue , Feminino , Humanos , Insulina/sangue , Masculino , Síndrome Metabólica/etiologia , Obesidade Abdominal/complicações , Fatores de Risco , Triglicerídeos/sangueRESUMO
Patients with epidermodysplasia verruciformis (EV) and biallelic null mutations of TMC6 (encoding EVER1) or TMC8 (EVER2) are selectively prone to disseminated skin lesions due to keratinocyte-tropic human ß-papillomaviruses (ß-HPVs), which lack E5 and E8. We describe EV patients homozygous for null mutations of the CIB1 gene encoding calcium- and integrin-binding protein-1 (CIB1). CIB1 is strongly expressed in the skin and cultured keratinocytes of controls but not in those of patients. CIB1 forms a complex with EVER1 and EVER2, and CIB1 proteins are not expressed in EVER1- or EVER2-deficient cells. The known functions of EVER1 and EVER2 in human keratinocytes are not dependent on CIB1, and CIB1 deficiency does not impair keratinocyte adhesion or migration. In keratinocytes, the CIB1 protein interacts with the HPV E5 and E8 proteins encoded by α-HPV16 and γ-HPV4, respectively, suggesting that this protein acts as a restriction factor against HPVs. Collectively, these findings suggest that the disruption of CIB1-EVER1-EVER2-dependent keratinocyte-intrinsic immunity underlies the selective susceptibility to ß-HPVs of EV patients.
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Betapapillomavirus/imunologia , Proteínas de Ligação ao Cálcio/imunologia , Epidermodisplasia Verruciforme/imunologia , Imunidade Inata , Queratinócitos/imunologia , Proteínas de Membrana/imunologia , Complexos Multiproteicos/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Adesão Celular/imunologia , Movimento Celular/imunologia , Epidermodisplasia Verruciforme/patologia , Feminino , Papillomavirus Humano 16/imunologia , Humanos , Queratinócitos/patologia , Masculino , Pessoa de Meia-Idade , Proteínas Oncogênicas Virais/imunologiaRESUMO
Biallelic loss-of-function (LOF) mutations of the NCF4 gene, encoding the p40phox subunit of the phagocyte NADPH oxidase, have been described in only 1 patient. We report on 24 p40phox-deficient patients from 12 additional families in 8 countries. These patients display 8 different in-frame or out-of-frame mutations of NCF4 that are homozygous in 11 of the families and compound heterozygous in another. When overexpressed in NB4 neutrophil-like cells and EBV-transformed B cells in vitro, the mutant alleles were found to be LOF, with the exception of the p.R58C and c.120_134del alleles, which were hypomorphic. Particle-induced NADPH oxidase activity was severely impaired in the patients' neutrophils, whereas PMA-induced dihydrorhodamine-1,2,3 (DHR) oxidation, which is widely used as a diagnostic test for chronic granulomatous disease (CGD), was normal or mildly impaired in the patients. Moreover, the NADPH oxidase activity of EBV-transformed B cells was also severely impaired, whereas that of mononuclear phagocytes was normal. Finally, the killing of Candida albicans and Aspergillus fumigatus hyphae by neutrophils was conserved in these patients, unlike in patients with CGD. The patients suffer from hyperinflammation and peripheral infections, but they do not have any of the invasive bacterial or fungal infections seen in CGD. Inherited p40phox deficiency underlies a distinctive condition, resembling a mild, atypical form of CGD.
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Doença Granulomatosa Crônica/genética , Mutação com Perda de Função , Fosfoproteínas/deficiência , Fosfoproteínas/genética , Adolescente , Adulto , Alelos , Criança , Pré-Escolar , Feminino , Técnicas de Inativação de Genes , Doença Granulomatosa Crônica/diagnóstico , Doença Granulomatosa Crônica/metabolismo , Células HEK293 , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas Mutantes/genética , Proteínas Mutantes/metabolismo , NADPH Oxidases/genética , NADPH Oxidases/metabolismo , Linhagem , Fagócitos/imunologia , Fagócitos/metabolismo , Fagócitos/microbiologia , Fenótipo , Fosfoproteínas/metabolismo , Prognóstico , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transdução Genética , Adulto JovemRESUMO
Previous studies have shown that heat stress triggers a process of programmed cell death in Leishmania infantum promastigotes that resembles apoptosis in higher eukaryotes. Even though this cell death process takes about 40 h to be completed, several early changes in the heat-stressed cells can be observed. Hyperpolarization of the parasite mitochondrion is the earliest event detected, which correlates with an increase in respiration rates and a concomitant increase in superoxide radical production. Induction of oxidative stress seems to mediate the heat-induced cell death process, as indicated by the partial prevention of parasite death observed when cell cultures are supplemented with N-acetyl-cysteine or glutathione. These antioxidants are able to diminish the concentration of superoxide radical but they do not prevent mitochondrial hyperpolarization. Treatment of the heat stressed parasites with the inhibitors of the mitochondrial respiration TTFA, antimycin A and KCN significantly decreases the production of superoxide radicals, which confirms the mitochondrial origin of this reactive oxygen species.
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Apoptose , Resposta ao Choque Térmico , Leishmania infantum/metabolismo , Mitocôndrias/metabolismo , Superóxidos/metabolismo , Animais , Antioxidantes/farmacologia , Citometria de Fluxo , Leishmania infantum/efeitos dos fármacos , Potencial da Membrana Mitocondrial , Estresse Oxidativo , Oxigênio/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/metabolismo , Fatores de TempoRESUMO
RESUMEN Antecedentes el síndrome metabólico en niños aumenta el riesgo de diabetes mellitus tipo 2 y enfermedad cardiovascular en la adultez. Objetivo describir los componentes del síndrome metabólico en niños, su prevalencia y criterios diagnósticos propuestos por diferentes organizaciones y autores. Materiales y métodos se realizó una búsqueda bibliográfica en las siguientes bases de datos: Pubmed, Science Direct, Embase, Lilacs y Scielo. Resultados y discusión varias organizaciones han establecido definiciones para diagnosticar el síndrome metabólico en niños, algunas abordando criterios utilizados en adultos o adoptando puntos de corte derivados de poblaciones seleccionadas como niños obesos o sin incluir niños pre-adolescentes, aduciendo en estos últimos una baja prevalencia de alteraciones. Así, la prevalencia de este síndrome en una misma población puede variar (0,9 a 11,4%) según la definición empleada. Sin embargo, dicha prevalencia aumenta con el grado de obesidad infantil y se han demostrado prevalencias altas en pre-púberes, independiente de la clasificación empleada. Recientemente, se propuso usar puntajes continuos para mejorar la evaluación en niños. Conclusión los puntos de corte actualmente empleados ponderan de forma diferente los componentes del síndrome metabólico. Por tanto, se recomienda emplear percentiles según edad, sexo y población para cada componente y evaluar la utilidad de puntajes continuos en esta población.
ABSTRACT Background The metabolic syndrome in children increases the risk for type 2 diabetes and cardiovascular disease in adulthood. Aim To describe the components of metabolic syndrome in children, their prevalence, and diagnostic criteria proposed by different authors and organizations. Materials and methods A literature search of articles published in Pubmed, Science Direct, Embase, Lilacs and Scielo databases was conducted. Results and discussion: Several organizations have established definitions for metabolic syndrome diagnosis in children, some including criteria used for adults or adopting cutoffs derived from selected populations such as obese children or without including pre-adolescent children, arguing a low prevalence of alterations in these. Thus, the prevalence of metabolic syndrome in a particular population varies (0,9% to 11,4%) according to the definition used. However, this prevalence increases according to the obesity grade, and a high prevalence in pre-pubers has been reported, independent of the classification used. Recently, it was proposed the use of a continuous score to improve the metabolic syndrome evaluation in children. Conclusion: The cutoffs currently used give different weighting for each component of metabolic syndrome. Therefore, it is recommended the use of percentiles according to sex and age and population for each component and to evaluate the utility of continuous scores in this population.
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The phagocytic NADPH-oxidase is a multiprotein system activated during the inflammatory response to produce superoxide anion (O2-), which is the substrate for formation of additional reactive oxygen species (ROS). The importance of this system for innate immunity is established by chronic granulomatous disease (CGD), a primary immunodeficiency caused by defects in the NADPH oxidase. In this review, we present and discuss recent knowledge about p40phox, the last NADPH oxidase component to be identified. Furthermore, its interaction with cellular pathways outside of the NADPH oxidase is discussed. Described in this review is evidence that p40phox participates in NADPH oxidase dynamics within cells, what is known about its role in the oxidase, the possibility that p40phox participates in non-NADPH oxidase processes in phagocytic and non-phagocytic cells and whether p40phox could mediate a similar function in other NADPH oxidases. An improved understanding of p40phox should provide new insights about NADPH oxidase, the physiology of phagocytic cells and the innate immune system.