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The skin of fish is a physicochemical barrier that is characterized by being formed by cells that secrete molecules responsible for the first defense against pathogenic organisms. In this study, the biological activity of peptides from mucus of Seriola lalandi and Seriolella violacea were identified and characterized. To this purpose, peptide extraction was carried out from epidermal mucus samples of juveniles of both species, using chromatographic strategies for purification. Then, the peptide extracts were characterized to obtain the amino acid sequence by mass spectrometry. Using bioinformatics tools for predicting antimicrobial and antioxidant activity, 12 peptides were selected that were chemically produced by simultaneous synthesis using the Fmoc-Tbu strategy. The results revealed that the synthetic peptides presented a random coil or extended secondary structure. The analysis of antimicrobial activity allowed it to be discriminated that four peptides, named by their synthesis code 5065, 5069, 5070, and 5076, had the ability to inhibit the growth of Vibrio anguillarum and affected the copepodite stage of C. rogercresseyi. On the other hand, peptides 5066, 5067, 5070, and 5077 had the highest antioxidant capacity. Finally, peptides 5067, 5069, 5070, and 5076 were the most effective for inducing respiratory burst in fish leukocytes. The analysis of association between composition and biological function revealed that the antimicrobial activity depended on the presence of basic and aromatic amino acids, while the presence of cysteine residues increased the antioxidant activity of the peptides. Additionally, it was observed that those peptides that presented the highest antimicrobial capacity were those that also stimulated respiratory burst in leukocytes. This is the first work that demonstrates the presence of functional peptides in the epidermal mucus of Chilean marine fish, which provide different biological properties when the fish face opportunistic pathogens.
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Aquicultura , Peixes , Muco , Animais , Muco/química , Chile , Antioxidantes/farmacologia , Antioxidantes/química , Antioxidantes/isolamento & purificação , Peptídeos/farmacologia , Peptídeos/química , Peptídeos/isolamento & purificação , Vibrio/efeitos dos fármacos , Epiderme/efeitos dos fármacos , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/isolamento & purificaçãoRESUMO
OBJECTIVE: To address the relationship between systemic lupus erythematosus (SLE) disease activity and the functional parameters of the innate immunity. METHODS: We evaluated a cohort of 26 adult SLE patients and 10 sex and age-paired healthy donors. When the patients had a disease flare (baseline) and when they achieve clinical response (follow-up), we assessed the systemic lupus erythematosus disease activity index 2 K (SLEDAI 2 K) and the following parameters with flow cytometry and confocal microscopy: monocyte subsets, their expression of TLR2, phagocytic monocytes and neutrophils using the pHrodo Red E. coli BioParticles, the respiratory burst with 123-dihydrorhodamine in neutrophils, and the spontaneous and lipopolysaccharide (LPS)-induced production of neutrophil extracellular traps (NETs). We used the Wilcoxon test to compare the paired medians with interquartile range (IQR) and the Mann-Whitney U test for independent medians. To assess the effect of prednisone and SLEDAI 2 K on the mentioned parameters, we applied a generalized mixed linear model. RESULTS: Twenty-three patients (88.4%) were women. The SLEDAI 2 K was higher at baseline 8 (6-14) in comparison to that at follow-up (6 (4-8), P = 0.028). At baseline, SLE patients had a decreased percentage of intermediate monocytes, a higher expression of TLR2 in total monocytes, increased phagocytosis in monocytes and neutrophils, a decreased respiratory burst intensity, and an increased production of NETs. In the mix model, the SLEDAI 2 K was the main factor influencing these functional innate immune parameters. CONCLUSION: Disease activity regulates the innate immune function in SLE which may contribute to the clinical features and infection predisposition. Key points ⢠This is the first cohort study addressing the effect of disease activity and prednisone use on the innate immune function of lupus patients. ⢠Our results show that the disease activity is a key regulator of the respiratory burst, phagocytosis, and the production of neutrophil extracellular traps. ⢠Also, we observed a differential proportion of monocyte subsets according to SLE disease activity. ⢠We consider that our manuscript contributes to the evidence addressing the intrinsic immune abnormalities of patients with SLE regardless of the use of immunosuppressants and set the bases for new research work considering the disease activity as an element to decide the prescription and duration of antibiotic prophylaxis in SLE patients, which is of interest to all rheumatologists.
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Lúpus Eritematoso Sistêmico , Receptor 2 Toll-Like , Adulto , Humanos , Feminino , Masculino , Prednisona/uso terapêutico , Estudos de Coortes , Escherichia coli , Lúpus Eritematoso Sistêmico/tratamento farmacológico , ImunidadeRESUMO
The extracellular purinergic agonist uridine diphosphate glucose (UDP-G) activates chemotaxis of human neutrophils (PMN) and the recruitment of PMN at the lung level, via P2Y14 purinergic receptor signaling. This effect is similar to the activation of PMN with N-formyl-methionyl-leucyl-phenylalanine (fMLP), a mechanism that also triggers the production of superoxide anion and hydrogen peroxide via the NADPH oxidase system. However, the effects of UDP-G on this system have not been studied. Defects in the intracellular phagocyte respiratory burst (RB) cause recurrent infections, immunodeficiency, and chronic and severe diseases in affected patients, often with sepsis and hypoxia. The extracellular activation of PMN by UDP-G could affect the RB and oxidative stress (OS) in situations of inflammation, infection and/or sepsis. The association of PMNs activation by UDP-G with OS and RB was studied. OS was evaluated by measuring spontaneous chemiluminescence (CL) of PMNs with a scintillation photon counter, and RB by measuring oxygen consumption with an oxygen Clark electrode at 37 °C, in non-stimulated cells and after activation (15 min) with lipopolysaccharides (LPS, 2 µg/mL), phorbol myristate acetate (PMA, 20 ng/mL), or UDP-G (100 µM). The stimulation index (SI) was calculated in order to establish the activation effect of the three agonists. After stimulation with LPS or PMA, the activated PMNs (0.1 × 106 cells/mL) showed an increase in CL (35%, p < 0.05 and 56%, p < 0.01, SI of 1.56 and 2.20, respectively). Contrariwise, the stimulation with UDP-G led to a decreased CL in a dose-dependent manner (60%, 25 µM, p < 0.05; 90%, 50-150 µM, p < 0.001). Nonetheless, despite the lack of oxidative damage, UDP-G triggered RB (SI 1.8) in a dose-dependent manner (38-50%, 100-200 µM, p < 0.0001). UDP-G is able to trigger NADPH oxidase activation in PMNs. Therefore, the prevention of OS and oxidative damage observed upon PMN stimulation with UDP-G indicates an antioxidant property of this molecule which is likely due to the activation of antioxidant defenses. Altogether, LPS and UDP-G have a synergistic effect, suggesting a key role in infection and/or sepsis.
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Introducción: La enfermedad granulomatosa crónica es una inmunodeficiencia primaria congénita del sistema inmune innato, originada por defectos en el complejo enzimático nicotinamida adenina dinucleótido fosfato oxidasa presente en células fagocíticas. Estos defectos funcionales causan incapacidad para producir especies reactivas del oxígeno en los fagocitos, que afectan la eliminación de algunos microorganismos patógenos dentro del fagolisosoma. El diagnóstico de esta enfermedad se realiza actualmente mediante la prueba de 1,2,3-dihidrorodamina asistida por citometría de flujo multiparamétrica, o la tinción de fagocitos con nitroazul de tetrazolio asistida por microscopio óptico. Objetivos: Describir los aspectos fisiopatológicos y moleculares de la enfermedad granulomatosa crónica; y discutir aspectos relacionados con las pruebas de diagnóstico antes mencionadas. Métodos: Se realizó una investigación bibliográfica-documental a partir de artículos científicos publicados desde 1933 hasta 2018, para ello fueron consultadas las bases de datos SciELO, PubMed y Springer. Desarrollo: Se exponen las características fisiopatológicas de la enfermedad granulomatosa crónica, así como la relación entre las mutaciones genéticas más abundantes en la población afectada y la gravedad de las manifestaciones clínicas que presentan los pacientes. Además, se analizan críticamente los beneficios y las deficiencias de dos técnicas que se utilizan actualmente para diagnosticar la enfermedad. Conclusiones: La enfermedad granulomatosa crónica puede generar consecuencias inmunológicas e inflamatorias graves, que se hallan en consonancia con las características genéticas expresadas en el complejo enzimático dañado. El diagnóstico de la enfermedad resulta más confiable, exhaustivo y específico, mediante la citometría de flujo y su prueba de 1,2,3-dihidrorodamina(AU)
Introduction: Chronic granulomatous disease is a congenital primary immunodeficiency of the innate immune system, caused by defects in the nicotinamide adenine dinucleotide phosphate oxidase enzyme complex present in phagocytic cells. These functional defects cause inability to produce reactive oxygen species in phagocytes, affecting the elimination of some pathogenic microorganisms within the phagolysosome. The diagnosis of this disease is currently made by means of the 1,2,3-dihydrorodamine test assisted by multiparametric flow cytometry, or the staining of phagocytes with nitro-blue tetrazolium assisted by light microscopy. Objectives: To characterize molecular and pathophysiologically the chronic granulomatous disease; and to discuss aspects related to the aforementioned diagnostic tests. Methods: In this work, a bibliographic-documentary research was carried out from scientific articles published from 1933 to 2018, for which the SciELO, PubMed and Springer databases were consulted. Development: The pathophysiological characteristics of chronic granulomatous disease are exposed, as well as the relationship between the most abundant genetic mutations in the affected population, and the severity of the clinical manifestations presented by the patients. In addition, the benefits and deficiencies of two techniques currently used to diagnose the disease are critically analyzed. Conclusions: Chronic granulomatous disease can generate severe immunological and inflammatory consequences, which are in line with the genetic characteristics expressed in the damaged enzyme complex. The diagnosis of the disease is more reliable, exhaustive and specific, using flow cytometry and its 1,2,3-dihydrorodamine test(AU)
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Humanos , Espécies Reativas de Oxigênio , Testes Diagnósticos de Rotina , Nitroazul de Tetrazólio/uso terapêutico , Técnicas e Procedimentos Diagnósticos , Citometria de Fluxo/métodos , Doença Granulomatosa Crônica/fisiopatologia , Doença Granulomatosa Crônica/genéticaRESUMO
BACKGROUND: Silver sulfadiazine (SSD) has been widely used in burned patients for the prevention of local infections. To be biologically active and exert antimicrobial properties, silver needs to be present in the form of silver ions (Ag1+) that bind to negatively charged proteins, namely, the RNA and DNA in microorganisms. However, previous published studies conducted with SSD in the 1990s reported a high level of silver absorption through damaged skin and noted the potential cytotoxicity of Ag1+ to human cells. SSD toxicity, however, had been described in cell cultures using arbitrary silver concentrations. In the present study, we determined the serum silver levels in burned patients treated with SSD and, taking into account the molar Ag1+ concentrations found in these patients, we evaluated the Ag1+ toxicity effects on inflammatory cells (ROS and cytokine production) in vitro. METHODS: Twenty patients with an average burned body surface area of 27.68% were included in this study. RESULTS: Patients' Ag1+ serum levels reached up to 558 times those of the unexposed controls. Ag1+ was then added to inflammatory cells in vitro at levels up to 2000 times the level of the control, and there was no effect on the viability of the cells nor on the rate of apoptosis. We observed a decrease in reactive oxygen species production by mononuclear (MN) and polymorphonuclear (PMN) cells, as well as a substantial decrease in cytokines IL-1ß, IL-6, IL-8, IL-10, and TNF-α production by leukocytes (MN and PNM). CONCLUSION: These findings suggest that Ag1+ may contribute to negative outcomes after burns, decreasing the primary defense mechanism (respiratory burst) and altering cytokine production.
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Anti-Infecciosos Locais/toxicidade , Anti-Infecciosos Locais/uso terapêutico , Queimaduras/tratamento farmacológico , Leucócitos Mononucleares/efeitos dos fármacos , Neutrófilos/efeitos dos fármacos , Nitrato de Prata/toxicidade , Sulfadiazina de Prata/uso terapêutico , Prata/sangue , Adulto , Apoptose/efeitos dos fármacos , Superfície Corporal , Sobrevivência Celular/efeitos dos fármacos , Feminino , Humanos , Técnicas In Vitro , Interleucina-10/metabolismo , Interleucina-1beta/efeitos dos fármacos , Interleucina-1beta/metabolismo , Interleucina-6/metabolismo , Interleucina-8/efeitos dos fármacos , Interleucina-8/metabolismo , Leucócitos Mononucleares/metabolismo , Masculino , Neutrófilos/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Fator de Necrose Tumoral alfa/efeitos dos fármacos , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Here we report the effects of exogenous and endogenous galectin-1 (Gal-1) in modulating the functional responses of human and murine neutrophils at different stages of activation, i.e. naive, primed, and activated. Exposure to Gal-1 did not induce ROS production in either naive or N-formyl-methionyl-leucyl-phenylalanine-primed (fMLP; 10-9 M) neutrophils. However, Gal-1 elicited a concentration-dependent ROS production in neutrophils activated with fMLP at concentrations ranging from 10-8 M to 10-6 M. Additional fMLP (10-7 M) stimulation of fMLP-activated neutrophils increased ROS production, whose intensity was inversely related to the fMLP concentration used in the first activation step (10-8 M to 10-6 M), and was not influenced by the presence of Gal-1. Naive neutrophils treated with Gal-1 and then exposed to fMLP (10-6 M) or phorbol-12-myristate-13-acetate (10-7 M) produced less ROS, as compared to naive neutrophils not treated with Gal-1. Interestingly, these in vitro Gal-1 effects were associated with Gal-1 carbohydrate-binding activity and the ability to decrease FPR-1 (formyl peptide receptor 1) expression in naive human neutrophils. Conversely, positive ROS modulation by Gal-1 in activated neutrophils was not associated with FPR-1 expression but it was related to its carbohydrate recognition. In vitro, fMLP stimulation of Gal-1-/- mouse neutrophils produced more ROS than fMLP stimulation of Gal-1+/+ neutrophils and this effect may be associated with increased FPR-1 expression. Exogenous Gal-1 induced ROS production in Gal-1-/- mouse neutrophils more effectively than in Gal-1+/+ mouse neutrophils. Compared to Gal-1+/+ mice, Gal-1-/- mice exhibited lower bacterial load in the peritoneal fluid and peripheral blood, thus indicating a greater bactericidal activity in vivo. These findings demonstrate that endogenous Gal-1 restricts ROS generation that correlates with bacterial killing capacity in inflammatory neutrophils. Thus, endogenous and exogenous Gal-1 may either positively or negatively modulate the effector functions of neutrophils according to the cell activation stage.
Assuntos
Galectina 1/farmacologia , Neutrófilos/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Adulto , Animais , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , N-Formilmetionina Leucil-Fenilalanina/farmacologia , Ativação de Neutrófilo/efeitos dos fármacos , Receptores de Formil Peptídeo/metabolismo , Adulto JovemRESUMO
The epidemic clone of Klebsiella pneumoniae (Kpn), sequence type 258 (ST258), carbapenamase producer (KPC), commonly infects hospitalized patients that are left with scarce therapeutic option since carbapenems are last resort antibiotics for life-threatening bacterial infections. To improve prevention and treatment, we should better understand the biology of Kpn KPC ST258 infections. Our hypothesis was that Kpn KPC ST258 evade the first line of defense of innate immunity, the polymorphonuclear neutrophil (PMN), by decreasing its functional response. Therefore, our aim was to evaluate how the ST258 Kpn clone affects PMN responses, focusing on the respiratory burst, compared to another opportunistic pathogen, Escherichia coli (Eco). We found that Kpn KPC ST258 was unable to trigger bactericidal responses as reactive oxygen species (ROS) generation and NETosis, compared to the high induction observed with Eco, but both bacterial strains were similarly phagocytized and cause increases in cell size and CD11b expression. The absence of ROS induction was also observed with other Kpn ST258 strains negative for KPC. These results reflect certain selectivity in terms of the functions that are triggered in PMN by Kpn, which seems to evade specifically those responses critical for bacterial survival. In this sense, bactericidal mechanisms evasion was associated with a higher survival of Kpn KPC ST258 compared to Eco. To investigate the mechanisms and molecules involved in ROS inhibition, we used bacterial extracts (BE) and found that BE were able to inhibit ROS generation triggered by the well-known ROS inducer, fMLP. A sequence of experiments led us to elucidate that the polysaccharide part of LPS was responsible for this inhibition, whereas lipid A mediated the other responses that were not affected by bacteria, such as cell size increase and CD11b up-regulation. In conclusion, we unraveled a mechanism of immune evasion of Kpn KPC ST258, which may contribute to design more effective strategies for the treatment of these multi-resistant bacterial infections.
Assuntos
Infecções por Klebsiella/imunologia , Klebsiella pneumoniae/imunologia , Neutrófilos/imunologia , Explosão Respiratória/imunologia , Antígeno CD11b/imunologia , Escherichia coli/imunologia , Humanos , Espécies Reativas de Oxigênio/imunologia , Regulação para Cima/imunologiaRESUMO
Uric acid is the final product of purine metabolism in humans and is considered to be quantitatively the main antioxidant in plasma. In vitro studies showed that the oxidation of uric acid by peroxidases, in presence of superoxide, generates urate free radical and urate hydroperoxide. Urate hydroperoxide is a strong oxidant and might be a relevant intermediate in inflammatory conditions. However, the identification of urate hydroperoxide in cells and biological samples has been a challenge due to its high reactivity. By using mass spectrometry, we undoubtedly demonstrated the formation of urate hydroperoxide and its corresponding alcohol, hydroxyisourate during the respiratory burst in peripheral blood neutrophils and in human leukemic cells differentiated in neutrophils (dHL-60). The respiratory burst was induced by phorbol myristate acetate (PMA) and greatly increased oxygen consumption and superoxide production. Both oxygen consumption and superoxide production were further augmented by incubation with uric acid. Conversely, uric acid significantly decreased the levels of HOCl, probably because of the competition with chloride by the catalysis of myeloperoxidase. In spite of the decrease in HOCl, the overall oxidative status, measured by GSH/GSSG ratio, was augmented in the presence of uric acid. In summary, the present results support the formation of urate hydroperoxide, a novel oxidant in neutrophils oxidative burst. Urate hydroperoxide is a strong oxidant and alters the redox balance toward a pro-oxidative environment. The production of urate hydroperoxide in inflammatory conditions could explain, at least in part, the harmful effect associated to uric acid.
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Inflamação/sangue , Neutrófilos/metabolismo , Peróxidos/metabolismo , Espécies Reativas de Oxigênio/sangue , Ácido Úrico/análogos & derivados , Catálise , Linhagem Celular Tumoral , Radicais Livres/química , Radicais Livres/metabolismo , Humanos , Inflamação/patologia , Espectrometria de Massas , Neutrófilos/química , Oxirredução , Peroxidase/genética , Peroxidase/metabolismo , Peróxidos/química , Peróxidos/isolamento & purificação , Espécies Reativas de Oxigênio/isolamento & purificação , Superóxidos/química , Superóxidos/metabolismo , Ácido Úrico/química , Ácido Úrico/isolamento & purificação , Ácido Úrico/metabolismoRESUMO
Introducción: El estallido respiratorio (ER) de neutrófilos es fundamental para la defensa contra infecciones, proceso ausente o ineficaz en la EGC, una inmunodeficiencia primaria (IDP) diagnosticada mediante la prueba del NBT. Actualmente se destacan las técnicas por citometría de flujo como la DHR, realizada únicamente en el Instituto de Investigaciones en Ciencias de la Salud (IICS), habiendo sido aplicada sólo en niños sanos. Objetivo: Evaluar el ER de neutrófilos por las técnicas NBT y DHR en niños con sospecha clínica de EGC y describir sus características clínico-demográficas. Materiales y Métodos: Se incluyeron 36 niños de ambos sexos, menores de 17 años de edad, remitidos al IICS entre el 2014-2015 por médicos especialistas. Se extrajo sangre para evaluación del ER de neutrófilos y se aplicó un cuestionario. Resultados: La mediana de edad fue de 4 años, 56% varones. Predominaron los pacientes hospitalizados, la sepsis y forunculosis cutánea fueron las manifestaciones clínicas más frecuentes y un 72% presentó recurrencia de infecciones con mediana de 3 episodios/año. El promedio para el IE de neutrófilos fue de 38,1±13,7 en el ensayo DHR, y 87±17% de activación para la prueba del NBT. En 8 pacientes los valores fueron inferiores al considerado normal y en un niño se confirmó EGC, observándose un patrón de herencia ligada al X. Conclusión: La evaluación del ER de neutrófilos permitió detectar un caso de EGC, determinándose el patrón hereditario mediante la técnica DHR por primera vez en el país. Es esencial el empleo de herramientas diagnósticas disponibles en niños con sospecha clínica de IDPs, para la detección y tratamiento oportunos que mejoran su calidad de vida y reducen la mortalidad.
Introduction: The neutrophil`s respiratory burst (RB) is essential for the defense against infections, this process is absent or ineffective in the CGD, a primary immunodeficiency (PID) diagnosed by the NBT test. Techniques that used flow cytometry such as DHR, performed only at the Instituto de Investigaciones en Ciencias de la Salud (IICS), currently stand out, having been applied only to healthy children. Objective: To evaluate the neutrophil`s RB using the NBT and DHR techniques in children with clinical suspicion of CGD and to describe their clinical and demographic characteristics. Materials and methods: 36 children of both sexes, with less than 17 years of age, that were referred to the IICS by specialists physicians between the years 2014-2015 were included. A blood sample was obtained to evaluate the neutrophil`s RB and a questionnaire was applied. Results: The median age was of 4 years and 56 % were males. Predominantly the patients were hospitalized, being sepsis and cutanueos furunculosis the most frequent clinical manifestations and a 72 % presented recurrent infection with a median of 3 episodes/year. The average for the neutrophil´s stimulation index (EI) was 38,1±13,7 with the DHR test, and 87±17% of activation for the NBT test. In 8 patients the values obtained were below the ones considered as normal and in one child CGD was confirmed, in which an X-linked inheritance pattern was observed. Conclusion: The evaluation of the neutrophil`s RB allowed the detection of one case of CGD, and the inheritance pattern was determined by the DHR test for the first time in our country. The use of available diagnostic tools in children with clinical suspicion of PID is essential for the appropriate detection and treatment that improve the quality of life and reduce mortality.
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Neutrophils participate in innate immunity as the first line of host defense against microorganisms. However, exacerbated neutrophil activity can be harmful to surrounding tissues; this is important in a range of diseases, including allergic asthma and chronic obstructive pulmonary disease in humans, and equine asthma (also known as recurrent airway obstruction (RAO). Tamoxifen (TX) is a non-steroidal estrogen receptor modulator with effects on cell growth and survival. Previous preliminary studies showed that TX treatment in horses with induced acute pulmonary inflammation promoted early apoptosis of blood and BALF neutrophils, reduction of BALF neutrophils, and improvement in animals' clinical status. The aim of this study was to evaluate the in vitro effect of TX on functional tests in equine peripheral blood neutrophils. Chemotaxis, respiratory burst production and phagocytosis assays were performed on neutrophils isolated from peripheral blood samples from 10 healthy horses. Results showed that IL-8 stimulated cells decrease their chemotactic index when treated with TX (1 and 10µM). Respiratory burst production was also dampened after treatment with TX. In conclusion, these results confirm that tamoxifen has a direct action on equine peripheral blood neutrophils. However, more in vivo and in vitro studies are required to fully understand the mechanisms of action of TX on neutrophils, in order to elucidate if it can be used as treatment in disorders such as allergic asthma in humans and horses.
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Antineoplásicos Hormonais/efeitos adversos , Cavalos/fisiologia , Neutrófilos/efeitos dos fármacos , Tamoxifeno/efeitos adversos , Animais , Quimiotaxia/efeitos dos fármacos , Feminino , Masculino , Neutrófilos/fisiologia , Fagocitose/efeitos dos fármacos , Explosão Respiratória/efeitos dos fármacosRESUMO
Copper (Cu) deficiency increases occurrence of certain infectious diseases in animals, including infectious keratoconjunctivitis in bovines, a bacterial ocular inflammation caused by Moraxella bovis. Neutrophil leukocytes constitute the first phagocytic cells to arrive at infection sites for bacterial neutralization. The objective of this work was to evaluate whether the functionality of neutrophils against M. bovis is impaired in experimentally induced Cu deficiency in bovines using high molybdenum and sulfur levels in the diet. The Cu tissue values and the periocular achromotrichia observed in +Mo animals showed that the clinic phase of Cu deficiency was reached in this group. Instead, +Cu animals have not evidenced clinical signs or biochemical parameters of hypocuprosis. On the basis of our observations, we concluded that Cu deficiency has no effect on phagocytic and bactericidal activities of neutrophils against M. bovis. However, superoxide dismutase activity and peroxide hydrogen generation were significantly different between groups. Therefore, additional research to explain these results is merited to fully characterize the consequences of Cu status on the risk for infections under field conditions.
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Antibacterianos/farmacologia , Cobre/deficiência , Cobre/metabolismo , Peróxido de Hidrogênio/farmacologia , Moraxella bovis/efeitos dos fármacos , Neutrófilos/efeitos dos fármacos , Superóxido Dismutase/metabolismo , Animais , Antibacterianos/análise , Bovinos , Sobrevivência Celular/efeitos dos fármacos , Ativação Enzimática , Peróxido de Hidrogênio/análise , Neutrófilos/microbiologia , Fagocitose/efeitos dos fármacosRESUMO
Among the uremic toxins proven to affect the neutrophil function in humans with chronic kidney disease(CKD), guanidine compounds stand out. To achieve a clearer understanding of the mechanisms thataffect the immunity of uremic patients, the hypothesis that guanidine acetic acid (GAA) contributesto the inhibition of oxidative metabolism and an increase in neutrophil apoptosis in healthy dogswas investigated in vitro. To this end, neutrophils isolated from ten healthy dogs were incubated inpure RPMI 1640 (control) and enriched with 5 mg/L of GAA. Capillary flow cytometry was usedto quantify superoxide production in neutrophils with the probe (hydroethidine), in the presenceand absence of phorbol-12-myristate-13-acetate (PMA), in order to assess oxidative metabolism.Apoptotic indices were quantified using the Annexin V-PE system, with and without the inductiveeffect of camptothecin. Neutrophils isolated and incubated in a GAA-enriched medium producedsmaller amounts of superoxide (p 0.001) when activated with PMA, however, this inhibition ofoxidative metabolism occurred without significantly altering their viability or rate of apoptosis. Thus, the results show guanidine compounds contribute to immunosuppression in dogs with CKD.(AU)
Dentre as toxinas urêmicas que comprovadamente afetam a função neutrofílica na doença renalcrônica (DRC) em humanos, destacam-se os compostos guanidínicos. A fim de melhor entenderos mecanismos que afetam a imunidade de pacientes urêmicos, no presente estudo foi investigadain vitro a hipótese de que o composto guanidínico ácido guanidinicoacético (AGA) contribui parainibição do metabolismo oxidativo, aumentando a apoptose dos neutrófilos de cães saudáveis. Paratal, neutrófilos isolados de dez cães saudáveis foram incubados em meio de cultura RPMI 1640puro (controle) e enriquecido com 5 mg/L de AGA. Utilizando-se citometria de fluxo capilar paraa avaliação do metabolismo oxidativo, quantificou-se a produção de superóxido dos neutrófilosempregando-se a sonda hidroetidina, com e sem a presença do estímulo com acetato miristato deforbol (PMA). O índice apoptótico foi quantificado utilizando-se o sistema Anexina V-PE, com e semo efeito indutor da camptotecina. Os neutrófilos isolados e incubados em meio enriquecido com AGA,quando ativados com PMA, produziram uma menor quantidade de superóxido (p 0,001), porém talinibição do metabolismo oxidativo ocorreu sem alterar significativamente a viabilidade e a taxa deapoptose. Assim, os resultados evidenciam que os compostos guanidínicos podem contribuir paraimunossupressão de cães com DRC.(AU)
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Animais , Cães , Explosão Respiratória , Insuficiência Renal Crônica/patologia , Imunidade/imunologia , Uremia/patologia , Superóxidos , NeutrófilosRESUMO
Abstract Among the uremic toxins proven to affect the neutrophil function in humans with chronic kidney disease (CKD), guanidine compounds stand out. To achieve a clearer understanding of the mechanisms that affect the immunity of uremic patients, the hypothesis that guanidine acetic acid (GAA) contributes to the inhibition of oxidative metabolism and an increase in neutrophil apoptosis in healthy dogs was investigated in vitro. To this end, neutrophils isolated from ten healthy dogs were incubated in pure RPMI 1640 (control) and enriched with 5 mg/L of GAA. Capillary flow cytometry was used to quantify superoxide production in neutrophils with the probe (hydroethidine), in the presence and absence of phorbol-12-myristate-13-acetate (PMA), in order to assess oxidative metabolism. Apoptotic indices were quantified using the Annexin V-PE system, with and without the inductive effect of camptothecin. Neutrophils isolated and incubated in a GAA-enriched medium produced smaller amounts of superoxide (p 0.001) when activated with PMA, however, this inhibition of oxidative metabolism occurred without significantly altering their viability or rate of apoptosis. Thus, the results show guanidine compounds contribute to immunosuppression in dogs with CKD.
Resumo Dentre as toxinas urêmicas que comprovadamente afetam a função neutrofílica na doença renal crônica (DRC) em humanos, destacam-se os compostos guanidínicos. A fim de melhor entender os mecanismos que afetam a imunidade de pacientes urêmicos, no presente estudo foi investigada in vitro a hipótese de que o composto guanidínico ácido guanidinicoacético (AGA) contribui para inibição do metabolismo oxidativo, aumentando a apoptose dos neutrófilos de cães saudáveis. Para tal, neutrófilos isolados de dez cães saudáveis foram incubados em meio de cultura RPMI 1640 puro (controle) e enriquecido com 5 mg/L de AGA. Utilizando-se citometria de fluxo capilar para a avaliação do metabolismo oxidativo, quantificou-se a produção de superóxido dos neutrófilos empregando-se a sonda hidroetidina, com e sem a presença do estímulo com acetato miristato de forbol (PMA). O índice apoptótico foi quantificado utilizando-se o sistema Anexina V-PE, com e sem o efeito indutor da camptotecina. Os neutrófilos isolados e incubados em meio enriquecido com AGA, quando ativados com PMA, produziram uma menor quantidade de superóxido (p 0,001), porém tal inibição do metabolismo oxidativo ocorreu sem alterar significativamente a viabilidade e a taxa de apoptose. Assim, os resultados evidenciam que os compostos guanidínicos podem contribuir para imunossupressão de cães com DRC.
RESUMO
Among the uremic toxins proven to affect the neutrophil function in humans with chronic kidney disease(CKD), guanidine compounds stand out. To achieve a clearer understanding of the mechanisms thataffect the immunity of uremic patients, the hypothesis that guanidine acetic acid (GAA) contributesto the inhibition of oxidative metabolism and an increase in neutrophil apoptosis in healthy dogswas investigated in vitro. To this end, neutrophils isolated from ten healthy dogs were incubated inpure RPMI 1640 (control) and enriched with 5 mg/L of GAA. Capillary flow cytometry was usedto quantify superoxide production in neutrophils with the probe (hydroethidine), in the presenceand absence of phorbol-12-myristate-13-acetate (PMA), in order to assess oxidative metabolism.Apoptotic indices were quantified using the Annexin V-PE system, with and without the inductiveeffect of camptothecin. Neutrophils isolated and incubated in a GAA-enriched medium producedsmaller amounts of superoxide (p 0.001) when activated with PMA, however, this inhibition ofoxidative metabolism occurred without significantly altering their viability or rate of apoptosis. Thus, the results show guanidine compounds contribute to immunosuppression in dogs with CKD.
Dentre as toxinas urêmicas que comprovadamente afetam a função neutrofílica na doença renalcrônica (DRC) em humanos, destacam-se os compostos guanidínicos. A fim de melhor entenderos mecanismos que afetam a imunidade de pacientes urêmicos, no presente estudo foi investigadain vitro a hipótese de que o composto guanidínico ácido guanidinicoacético (AGA) contribui parainibição do metabolismo oxidativo, aumentando a apoptose dos neutrófilos de cães saudáveis. Paratal, neutrófilos isolados de dez cães saudáveis foram incubados em meio de cultura RPMI 1640puro (controle) e enriquecido com 5 mg/L de AGA. Utilizando-se citometria de fluxo capilar paraa avaliação do metabolismo oxidativo, quantificou-se a produção de superóxido dos neutrófilosempregando-se a sonda hidroetidina, com e sem a presença do estímulo com acetato miristato deforbol (PMA). O índice apoptótico foi quantificado utilizando-se o sistema Anexina V-PE, com e semo efeito indutor da camptotecina. Os neutrófilos isolados e incubados em meio enriquecido com AGA,quando ativados com PMA, produziram uma menor quantidade de superóxido (p 0,001), porém talinibição do metabolismo oxidativo ocorreu sem alterar significativamente a viabilidade e a taxa deapoptose. Assim, os resultados evidenciam que os compostos guanidínicos podem contribuir paraimunossupressão de cães com DRC.
Assuntos
Animais , Cães , Explosão Respiratória , Imunidade/imunologia , Insuficiência Renal Crônica/patologia , Uremia/patologia , Neutrófilos , SuperóxidosRESUMO
Due to the constant evolution of industrial poultry production and the global emergence of bacterial resistance to antibiotics there has been an increasing interest in alternatives for the treatment of poultry salmonellosis, such as phage therapy and probiotics. The present study evaluated the effects of the oral administration of the bacteriophage P22 and of a probiotic, consisting of four Lactobacillus species, on the level of circulating heterophils containing a superoxide anion of one-day-old broilers challenged with Salmonella Typhimurium for seven days. It was concluded that the treatment with a probiotic with lactobacilli of broilers experimentally infected with Salmonella spp eliminates this pathogen by increasing the circulating levels of reactive heterophils. When chicks are treated with a probiotic and a bacteriophage, the agent is eliminated with no changes in circulating reactive heterophil counts. It is also concluded that the heterophils of day-old chicks are not capable of producing superoxide anion. However, this capacity is detected after 48 h of life, indicating that heterophils mature as birds age.(AU)
Assuntos
Animais , Aves Domésticas/anormalidades , Aves Domésticas/microbiologia , Lactobacillus , Salmonella typhimurium , Infecções por SalmonellaRESUMO
We tested whether diethylcarbamazine (DEC) or ivermectin (IVM), both antiparasitic drugs with reported immunomodulatory properties, were able to affect the immune system to potentiate host defense mechanisms and protect against actinomycetoma in a mouse model. Male BALB/c mice of 10-12 weeks of age were injected with either Nocardia brasiliensis or saline solution. Recorded were the effects of a treatment by DEC (6 mg/kg per os daily for one week) or IVM (200 µg/kg subcutaneously on days 1 and 3) on (i) the development of mycetoma lesion, (ii) the expression of reactive oxygen intermediates (ROI) by phagocytes, (iii) the proliferation index of lymphocytes and (iv) antibody production of IgG and IgM. After an initial lesion in all mice, DEC inhibited a full development and progression of actinomycetoma resulting in a reduced lesion size (p < 0.001). IVM had no inhibitory effect on the development of mycetoma. Furthermore, DEC treatment was associated with a significant enhancement of ROI expression (p < 0.05) by polymorphonuclear neutrophils at day 3 after infection. Lymphocyte proliferation in response to N. brasiliensis antigens and concanavalin A in DEC-treated group was higher than in non-treated group at day 21 and 28 postinfection (p < 0.01). Significant changes in antibody response were not observed. By all parameters tested, DEC was superior to IVM regarding immunostimulatory potency. In conclusion, DEC expressed an in vivo influence on the immune status during the infection by N. brasiliensis leading to retrogression of the mycetoma and increasing cellular immune responses. Our findings may indicate a potential use of DEC as a putative adjuvant in infectious disease or vaccination.
Assuntos
Antiparasitários/administração & dosagem , Dietilcarbamazina/administração & dosagem , Ivermectina/administração & dosagem , Micetoma/tratamento farmacológico , Neutrófilos/efeitos dos fármacos , Nocardia/imunologia , Animais , Formação de Anticorpos/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Modelos Animais de Doenças , Humanos , Imunomodulação , Ativação Linfocitária/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Micetoma/imunologia , Neutrófilos/fisiologia , Espécies Reativas de Oxigênio/metabolismoRESUMO
Effects of β-glucan on innate immune responses and survival were studied in pacu experimentally infected with Aeromonas hydrophila. Fish fed diets containing 0, 0.1% and 1% β-glucan were injected with A. hydrophila. β-glucan enhanced fish survival in both treated groups (26.7% and 21.2% of the control, respectively). Leukocyte respiratory burst and alternative complement pathway activities were elevated after bacterial challenge regardless the β-glucan concentration. Lysozyme activity was higher after infection and showed a gradual increase as β-glucan concentration increased. A significant elevation in WBC count was observed either after bacterial challenge or by influence of β-glucan separately. The same response was observed in the number of thrombocytes, lymphocytes, eosinophils, LG-PAS positive cell and monocytes. It can be concluded that feeding pacu with β-glucan can increase protection against A. hydrophila, due to changes in non-specific immune responses.
Os efeitos da β-glucana sobre as respostas imunes inatas e a sobrevivência foram estudados em pacu experimentalmente infectado com Aeromonas hydrophila. Peixes alimentados com dietas contendo 0,1% e 1% de β-glucana foram injetados com 1 × 108 CFU de A. hydrophila após 7 dias de alimentação. A sobrevivência de peixes foi maior nos dois grupos tratados em comparação ao grupo controle (26,7% e 21,2%, respectivamente). A atividade respiratória de leucócitos e a atividade hemolítica do complemento – via alternativa estavam elevadas após desafio bacteriano independentemente da concentração de β-glucana. A atividade de lisozima foi maior após a infecção e mostrou um aumento gradual de acordo com a concentração do imunoestimulante. Observou-se um aumento significativo na contagem de leucócitos totais após o desafio bacteriano e influência de β-glucana. A mesma resposta foi observada para trombócitos, linfócitos, eosinófilos, leucócito PAS positivo e monócitos. Com exceção de neutrófilos, que diminuíram frente ao mais alto nível do imunoestimulante e não se alteraram após a infecção, as outras células aumentaram após a exposição à A. hydrophila. A β-glucana não afetou os níveis de proteína total do soro, que aumentaram após o desafio bacteriano. Conclui-se que a administração de β-glucana em pacu pode aumentar a proteção contra A. hydrophila, por alterações nas respostas imunes de não-específicas.
Assuntos
Animais , Aeromonas hydrophila , Ração Animal , Resistência à Doença/imunologia , Doenças dos Peixes/imunologia , Infecções por Bactérias Gram-Negativas/veterinária , beta-Glucanas/administração & dosagem , Resistência à Doença/efeitos dos fármacos , Infecções por Bactérias Gram-Negativas/imunologia , Análise de SobrevidaRESUMO
Effects of β-glucan on innate immune responses and survival were studied in pacu experimentally infected with Aeromonas hydrophila. Fish fed diets containing 0, 0.1% and 1% β-glucan were injected with A. hydrophila. β-glucan enhanced fish survival in both treated groups (26.7% and 21.2% of the control, respectively). Leukocyte respiratory burst and alternative complement pathway activities were elevated after bacterial challenge regardless the β-glucan concentration. Lysozyme activity was higher after infection and showed a gradual increase as β-glucan concentration increased. A significant elevation in WBC count was observed either after bacterial challenge or by influence of β-glucan separately. The same response was observed in the number of thrombocytes, lymphocytes, eosinophils, LG-PAS positive cell and monocytes. It can be concluded that feeding pacu with β-glucan can increase protection against A. hydrophila, due to changes in non-specific immune responses.(AU)
Os efeitos da β-glucana sobre as respostas imunes inatas e a sobrevivência foram estudados em pacu experimentalmente infectado com Aeromonas hydrophila. Peixes alimentados com dietas contendo 0,1% e 1% de β-glucana foram injetados com 1 × 108 CFU de A. hydrophila após 7 dias de alimentação. A sobrevivência de peixes foi maior nos dois grupos tratados em comparação ao grupo controle (26,7% e 21,2%, respectivamente). A atividade respiratória de leucócitos e a atividade hemolítica do complemento via alternativa estavam elevadas após desafio bacteriano independentemente da concentração de β-glucana. A atividade de lisozima foi maior após a infecção e mostrou um aumento gradual de acordo com a concentração do imunoestimulante. Observou-se um aumento significativo na contagem de leucócitos totais após o desafio bacteriano e influência de β-glucana. A mesma resposta foi observada para trombócitos, linfócitos, eosinófilos, leucócito PAS positivo e monócitos. Com exceção de neutrófilos, que diminuíram frente ao mais alto nível do imunoestimulante e não se alteraram após a infecção, as outras células aumentaram após a exposição à A. hydrophila. A β-glucana não afetou os níveis de proteína total do soro, que aumentaram após o desafio bacteriano. Conclui-se que a administração de β-glucana em pacu pode aumentar a proteção contra A. hydrophila, por alterações nas respostas imunes de não-específicas.(AU)
Assuntos
Animais , Aeromonas hydrophila , Ração Animal , Resistência à Doença/imunologia , Doenças dos Peixes/imunologia , Infecções por Bactérias Gram-Negativas/veterinária , beta-Glucanas/administração & dosagem , Infecções por Bactérias Gram-Negativas/imunologia , Análise de SobrevidaRESUMO
Dystroglycan has recently been characterized in blood tissue cells, as part of the dystrophin glycoprotein complex but to date nothing is known of its role in the differentiation process of neutrophils. We have investigated the role of dystroglycan in the human promyelocytic leukemic cell line HL-60 differentiated to neutrophils. Depletion of dystroglycan by RNAi resulted in altered morphology and reduced properties of differentiated HL-60 cells, including chemotaxis, respiratory burst, phagocytic activities and expression of markers of differentiation. These findings strongly implicate dystroglycan as a key membrane adhesion protein involved in the differentiation process in HL-60 cells.
Assuntos
Diferenciação Celular/fisiologia , Distroglicanas/fisiologia , Neutrófilos/citologia , Neutrófilos/fisiologia , Biomarcadores/metabolismo , Movimento Celular , Quimiotaxia de Leucócito , Distroglicanas/antagonistas & inibidores , Distroglicanas/genética , Células HL-60 , Humanos , Fagocitose , Fenótipo , Interferência de RNA , RNA Interferente Pequeno/genética , Explosão RespiratóriaRESUMO
Due to the constant evolution of industrial poultry production and the global emergence of bacterial resistance to antibiotics there has been an increasing interest in alternatives for the treatment of poultry salmonellosis, such as phage therapy and probiotics. The present study evaluated the effects of the oral administration of the bacteriophage P22 and of a probiotic, consisting of four Lactobacillus species, on the level of circulating heterophils containing a superoxide anion of one-day-old broilers challenged with Salmonella Typhimurium for seven days. It was concluded that the treatment with a probiotic with lactobacilli of broilers experimentally infected with Salmonella spp eliminates this pathogen by increasing the circulating levels of reactive heterophils. When chicks are treated with a probiotic and a bacteriophage, the agent is eliminated with no changes in circulating reactive heterophil counts. It is also concluded that the heterophils of day-old chicks are not capable of producing superoxide anion. However, this capacity is detected after 48 h of life, indicating that heterophils mature as birds age.