RESUMO
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection triggers activation of the NLRP3 inflammasome, which promotes inflammation and aggravates severe COVID-19. Here, we report that SARS-CoV-2 induces upregulation and activation of human caspase-4/CASP4 (mouse caspase-11/CASP11), and this process contributes to NLRP3 activation. In vivo infections performed in transgenic hACE2 humanized mice, deficient or sufficient for Casp11, indicate that hACE2 Casp11-/- mice were protected from disease development, with the increased pulmonary parenchymal area, reduced clinical score of the disease, and reduced mortality. Assessing human samples from fatal cases of COVID-19, we found that CASP4 was expressed in patient lungs and correlated with the expression of inflammasome components and inflammatory mediators, including CASP1, IL1B, IL18, and IL6. Collectively, our data establish that CASP4/11 promotes NLRP3 activation and disease pathology, revealing a possible target for therapeutic interventions for COVID-19.
Assuntos
COVID-19 , Inflamassomos , Camundongos , Animais , Humanos , Inflamassomos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Macrófagos/metabolismo , COVID-19/metabolismo , SARS-CoV-2/metabolismo , Camundongos TransgênicosRESUMO
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) induces mild or asymptomatic COVID-19 in most cases, but some patients develop an excessive inflammatory process that can be fatal. As the NLRP3 inflammasome and additional inflammasomes are implicated in disease aggravation, drug repositioning to target inflammasomes emerges as a strategy to treat COVID-19. Here, we performed a high-throughput screening using a 2560 small-molecule compound library and identified FDA-approved drugs that function as pan-inflammasome inhibitors. Our best hit, niclosamide (NIC), effectively inhibits both inflammasome activation and SARS-CoV-2 replication. Mechanistically, induction of autophagy by NIC partially accounts for inhibition of NLRP3 and AIM2 inflammasomes, but NIC-mediated inhibition of NAIP/NLRC4 inflammasome are autophagy independent. NIC potently inhibited inflammasome activation in human monocytes infected in vitro, in PBMCs from patients with COVID-19, and in vivo in a mouse model of SARS-CoV-2 infection. This study provides relevant information regarding the immunomodulatory functions of this promising drug for COVID-19 treatment.
Assuntos
Tratamento Farmacológico da COVID-19 , Inflamassomos , Animais , Humanos , Agentes de Imunomodulação , Camundongos , Proteína 3 que Contém Domínio de Pirina da Família NLR , SARS-CoV-2RESUMO
The successful establishment of HIV-1 infection is related to inflammasome blocking or inactivation, which can result in the viral evasion of the immune responses and formation of reservoirs in several tissues. In this sense, we aimed to evaluate the viral and cellular mechanisms activated during HIV-1 infection in human primary macrophages that allow an effective viral replication in these cells. We found that resting HIV-1-infected macrophages, but not those activated in classical or alternative patterns, released IL-1ß and other pro-inflammatory cytokines, and showed increased CXCL10 expression, without changes in the NLRP3, AIM2 or RIG-I inflammasome pathways. Also, similar levels of Casp-1, phosphorylated NF-κB (p65) and NLRP3 proteins were found in uninfected and HIV-1-infected macrophages. Likewise, no alterations were detected in ASC specks released in the culture supernatant after HIV-1 infection, suggesting that macrophages remain viable after infection. Using in silico prediction studies, we found that the HIV-1 proteins Gag and Vpr interact with several host proteins. Comparable levels of trans-LTB4 were found in the supernatants of uninfected and HIV-1-infected macrophages, whereas ROS production was impaired in infected cells, which was not reversed after the PMA stimulus. Immunofluorescence analysis showed structural alterations in the mitochondrial architecture and an increase of BIM in the cytoplasm of infected cells. Our data suggest that HIV-1 proteins Gag and Vpr, through interacting with cellular proteins in the early steps of infection, preclude the inflammasome activation and the development of effective immune responses, thus allowing the establishment of the infection.
Assuntos
Infecções por HIV , HIV-1 , Infecções por HIV/metabolismo , Humanos , Inflamassomos , Interleucina-1beta/metabolismo , Macrófagos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Infecção PersistenteRESUMO
Uncontrolled inflammatory responses play a critical role in coronavirus disease (COVID-19). In this context, because the triggering-receptor expressed on myeloid cells-1 (TREM-1) is considered an intrinsic amplifier of inflammatory signals, this study investigated the role of soluble TREM-1 (sTREM-1) as a biomarker of the severity and mortality of COVID-19. Based on their clinical scores, we enrolled COVID-19 positive patients (n = 237) classified into mild, moderate, severe, and critical groups. Clinical data and patient characteristics were obtained from medical records, and their plasma inflammatory mediator profiles were evaluated with immunoassays. Plasma levels of sTREM-1 were significantly higher among patients with severe disease compared to all other groups. Additionally, levels of sTREM-1 showed a significant positive correlation with other inflammatory parameters, such as IL-6, IL-10, IL-8, and neutrophil counts, and a significant negative correlation was observed with lymphocyte counts. Most interestingly, sTREM-1 was found to be a strong predictive biomarker of the severity of COVID-19 and was related to the worst outcome and death. Systemic levels of sTREM-1 were significantly correlated with the expression of matrix metalloproteinases (MMP)-8, which can release TREM-1 from the surface of peripheral blood cells. Our findings indicated that quantification of sTREM-1 could be used as a predictive tool for disease outcome, thus improving the timing of clinical and pharmacological interventions in patients with COVID-19.
Assuntos
Biomarcadores/sangue , COVID-19/diagnóstico , COVID-19/mortalidade , Leucócitos/metabolismo , Metaloproteinase 8 da Matriz/metabolismo , Índice de Gravidade de Doença , Receptor Gatilho 1 Expresso em Células Mieloides/sangue , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Brasil , Feminino , Humanos , Inflamação , Interleucina-10/sangue , Interleucina-6/sangue , Interleucina-8/sangue , Contagem de Leucócitos , Masculino , Pessoa de Meia-Idade , Neutrófilos/metabolismo , Estudos Prospectivos , SARS-CoV-2 , Receptor Gatilho 1 Expresso em Células Mieloides/metabolismo , Adulto JovemRESUMO
Strategies capable of attenuating TLR4 can attenuate metabolic processes such as inflammation, endoplasmic reticulum (ER) stress, and apoptosis in the body. Physical exercise has been a cornerstone in suppressing inflammation and dysmetabolic outcomes caused by TRL4 activation. Thus, the present study aimed to evaluate the effects of a chronic physical exercise protocol on the TLR4 expression and its repercussion in the inflammation, ER stress, and apoptosis pathways in mice hearts. Echocardiogram, RT-qPCR, immunoblotting, and histological techniques were used to evaluate the left ventricle of wild-type (WT) and Tlr4 knockout (TLR4 KO) mice submitted to a 4-week physical exercise protocol. Moreover, we performed a bioinformatics analysis to expand the relationship of Tlr4 mRNA in the heart with inflammation, ER stress, and apoptosis-related genes of several isogenic strains of BXD mice. The TLR4 KO mice had higher energy expenditure and heart rate in the control state but lower activation of apoptosis and ER stress pathways. The bioinformatics analysis reinforced these data. In the exercised state, the WT mice improved performance and cardiac function. However, these responses were blunted in the KO group. In conclusion, TLR4 has an essential role in the inhibition of apoptosis and ER stress pathways, as well as in the training-induced beneficial adaptations.
Assuntos
Apoptose/genética , Estresse do Retículo Endoplasmático/genética , Metabolismo Energético/genética , Ventrículos do Coração , Condicionamento Físico Animal , Receptor 4 Toll-Like/genética , Função Ventricular , Animais , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , Ecocardiografia , Deleção de Genes , Glicogênio/metabolismo , Frequência Cardíaca , Inflamação/genética , Inflamação/patologia , Camundongos , Camundongos Knockout , RNA Mensageiro/metabolismoRESUMO
Interleukin-6 (IL-6) is associated with pathological cardiac hypertrophy and can be dramatically increased in serum after an acute strenuous exercise session. However, IL-6 is also associated with the increased production and release of anti-inflammatory cytokines and the inhibition of tumor necrosis factor-alpha (TNF-α) after chronic moderate exercise. To elucidate the relevance of IL-6 in inflammatory and hypertrophic signaling in the heart in response to an acute strenuous exercise session, we combined transcriptome analysis using the BXD mice database and exercised IL-6 knockout mice (IL-6KO). Bioinformatic analysis demonstrated that low or high-levels of Il6 mRNA in the heart did not change the inflammation- and hypertrophy-related genes in BXD mice strains. On the other hand, bioinformatic analysis revealed a strong positive correlation between Il6 gene expression in skeletal muscle with inflammation-related genes in cardiac tissue in several BXD mouse strains, suggesting that skeletal muscle-derived IL-6 could alter the heart's intracellular signals, particularly the inflammatory signaling. As expected, an acute strenuous exercise session increased IL-6 levels in wild-type, but not in IL-6KO mice. Despite not showing morphofunctional differences in the heart at rest, the IL-6KO group presented a reduction in physical performance and attenuated IL-6, TNF-α, and IL-1beta kinetics in serum, as well as lower p38MAPK phosphorylation, Ampkalpha expression, and higher Acta1 and Tnf gene expressions in the left ventricle in the basal condition. In response to strenuous exercise, IL-6 ablation was linked to a reduction in the pro-inflammatory response and higher activation of classical physiological cardiac hypertrophy proteins.
Assuntos
Biomarcadores/metabolismo , Coração/fisiopatologia , Inflamação/patologia , Interleucina-6/deficiência , Condicionamento Físico Animal , Adenilato Quinase/metabolismo , Animais , Biomarcadores/sangue , Cardiomegalia/sangue , Cardiomegalia/genética , Eletrocardiografia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Coração/diagnóstico por imagem , Interleucina-6/genética , Interleucina-6/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Músculo Esquelético/metabolismo , Fosforilação , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Descanso , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismoRESUMO
Severe cases of COVID-19 are characterized by a strong inflammatory process that may ultimately lead to organ failure and patient death. The NLRP3 inflammasome is a molecular platform that promotes inflammation via cleavage and activation of key inflammatory molecules including active caspase-1 (Casp1p20), IL-1ß, and IL-18. Although participation of the inflammasome in COVID-19 has been highly speculated, the inflammasome activation and participation in the outcome of the disease are unknown. Here we demonstrate that the NLRP3 inflammasome is activated in response to SARS-CoV-2 infection and is active in COVID-19 patients. Studying moderate and severe COVID-19 patients, we found active NLRP3 inflammasome in PBMCs and tissues of postmortem patients upon autopsy. Inflammasome-derived products such as Casp1p20 and IL-18 in the sera correlated with the markers of COVID-19 severity, including IL-6 and LDH. Moreover, higher levels of IL-18 and Casp1p20 are associated with disease severity and poor clinical outcome. Our results suggest that inflammasomes participate in the pathophysiology of the disease, indicating that these platforms might be a marker of disease severity and a potential therapeutic target for COVID-19.
Assuntos
COVID-19/patologia , COVID-19/virologia , Inflamassomos/metabolismo , SARS-CoV-2/fisiologia , Índice de Gravidade de Doença , Apoptose , Comorbidade , Citocinas/biossíntese , Humanos , Pulmão/patologia , Monócitos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Mudanças Depois da Morte , Resultado do TratamentoRESUMO
Tuberculosis (TB) is the leading cause of mortality among infectious diseases worldwide. The study of molecular targets for therapy and diagnosis suggested that Notch signaling is an important pathway for the maintenance of the immune response during Mycobacterium tuberculosis (Mtb) infection. We evaluated the participation of the Notch pathway in the modulation of immune response during Mtb infection, and observed that patients with active TB had increased DLL4 expression in intermediate and non-classic monocytes. Further, patients with moderate and advanced lung injury have higher Notch1 expression in CD4+ T cells when compared to patients with a minimal lung injury. When we considered the severity of disease in active TB patients, the expression of the DLL4 in intermediate monocytes and the expression of Notch1 in CD4+ T cells are positively correlated with the degree of lung injury. In vitro, PBMCs treated with the Notch pharmacological inhibitor reduced the production of IL-17A and IL-2, whereas anti-hDLL4 treatment promoted a significant increase in TNF-α and phagocytosis. We suggest that Notch1 and DLL4 are associated with immune response activation in human tuberculosis, and can be a novel target to be exploited in the future in the searching of biomarkers.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Linfócitos T CD4-Positivos/metabolismo , Proteínas de Ligação ao Cálcio/metabolismo , Pulmão/metabolismo , Mycobacterium tuberculosis/imunologia , Receptor Notch1/metabolismo , Tuberculose Pulmonar/metabolismo , Adulto , Biomarcadores/metabolismo , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/microbiologia , Estudos de Casos e Controles , Células Cultivadas , Citocinas/metabolismo , Progressão da Doença , Feminino , Interações Hospedeiro-Patógeno , Humanos , Pulmão/imunologia , Pulmão/microbiologia , Masculino , Pessoa de Meia-Idade , Fagocitose , Índice de Gravidade de Doença , Transdução de Sinais , Tuberculose Pulmonar/imunologia , Tuberculose Pulmonar/microbiologia , Adulto JovemRESUMO
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
RESUMO
BACKGROUND: Toll-like receptor 4 (Tlr4) is recognized due to its role in the immune response. Also, this protein can participate in the signaling pathway of events triggered by physical exercise such as apoptosis, inflammation, and endoplasmic reticulum (ER) stress. The main objective of this study was to evaluate the role of Tlr4 in the markers of these events in the myocardium of mice submitted to acute physical exercise (APE) protocols at different intensities. METHODS: Echocardiogram, RT-qPCR, and immunoblotting technique were used to evaluate the left ventricle of wild-type (WT) and Tlr4 knockout (Tlr4 KO) submitted to APE protocols at 45, 60, and 75% of their maximal velocity. Also, we performed the bioinformatics analysis to establish the connection of heart mRNA levels of Tlr4 with heart genes of inflammation and ER stress of several isogenic strains of BXD mice. RESULTS: Under basal conditions, the Tlr4 deletion diminished the performance, and expression of inflammation and ER stress genes in the left ventricle, but increased the serum levels of CK, Il-17, and Tnf-alpha. Under the same exercise conditions, the Tlr4 deletion reduced the glycemia, serum levels of CK, Il-17, and Tnf-alpha, as well as genes and/or proteins related to apoptosis, inflammation and ER stress in the left ventricle, but increased the levels of CK-mb and LDH, as well as other genes related to apoptosis, inflammation, and ER stress in the left ventricle. CONCLUSION: Altogether, the current findings highlighted the effects of different acute exercise intensities were attenuated in the heart of Tlr4 KO mice.
Assuntos
Apoptose/fisiologia , Estresse do Retículo Endoplasmático/fisiologia , Coração/fisiologia , Inflamação , Esforço Físico/fisiologia , Receptor 4 Toll-Like/fisiologia , Animais , Apoptose/genética , Biologia Computacional , Creatina Quinase/sangue , Ecocardiografia , Estresse do Retículo Endoplasmático/genética , Coração/diagnóstico por imagem , Interleucina-17/sangue , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Esforço Físico/genética , Transdução de Sinais/fisiologia , Receptor 4 Toll-Like/genética , Fator de Necrose Tumoral alfa/sangueRESUMO
OBJECTIVE AND DESIGN: Investigate survival outcomes, and immunological and metabolomic effects of hyaluronidase (Hz) treatment during mouse models of acute inflammation and sepsis. METHODS: Survival of C57Bl/6 mice was monitored after lethal challenge with lipopolysaccharide (LPS) or cecal and ligation puncture (CLP)-induced sepsis and treated with Hz or saline. Mice were also challenged with LPS and treated with Hz for leukocyte counting, cytokine quantification and determination of metabolomic profiles in the peritoneal fluid. RESULTS: Hz treatment improved survival outcomes after lethal challenge with LPS or CLP-induced sepsis. LPS challenge promoted acute neutrophil accumulation and production of interleukin-1ß (IL-1ß) and IL-6 in the peritoneum, whereas Hz treatment suppressed neutrophil infiltration and cytokine production. We further characterized the metabolomic alterations caused by LPS challenge, which predicted activity of metabolic pathways related to fatty acids and eicosanoids. Hz treatment had a profound effect over the metabolic response, reflected by reductions of the relative levels of fatty acids. CONCLUSION: Collectively, these data demonstrate that Hz treatment is associated with metabolic reprogramming of pathways that sustain the inflammatory response.
Assuntos
Hialuronoglucosaminidase/farmacologia , Sepse/imunologia , Sepse/metabolismo , Doença Aguda , Animais , Líquido Ascítico/citologia , Líquido Ascítico/imunologia , Líquido Ascítico/metabolismo , Modelos Animais de Doenças , Eicosanoides/metabolismo , Ácidos Graxos/metabolismo , Imunomodulação , Interleucina-1beta/imunologia , Interleucina-6/imunologia , Contagem de Leucócitos , Lipopolissacarídeos , Masculino , Redes e Vias Metabólicas/efeitos dos fármacos , Metabolômica , Camundongos Endogâmicos C57BLRESUMO
Leishmania RNA virus (LRV) is an important virulence factor associated with the development of mucocutaneous Leishmaniasis, a severe form of the disease. LRV-mediated disease exacerbation relies on TLR3 activation, but downstream mechanisms remain largely unexplored. Here, we combine human and mouse data to demonstrate that LRV triggers TLR3 and TRIF to induce type I IFN production, which induces autophagy. This process results in ATG5-mediated degradation of NLRP3 and ASC, thereby limiting NLRP3 inflammasome activation in macrophages. Consistent with the known restricting role of NLRP3 for Leishmania replication, the signaling pathway triggered by LRV results in increased parasite survival and disease progression. In support of this data, we find that lesions in patients infected with LRV+ Leishmania are associated with reduced inflammasome activation and the development of mucocutaneous disease. Our findings reveal the mechanisms triggered by LRV that contribute to the development of the debilitating mucocutaneous form of Leishmaniasis.
Assuntos
Imunidade Inata/imunologia , Inflamassomos/imunologia , Leishmania/imunologia , Leishmaniose Mucocutânea/imunologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/imunologia , Vírus de RNA/imunologia , Receptor 3 Toll-Like/imunologia , Animais , Autofagia/imunologia , Humanos , Interleucina-1beta/imunologia , Interleucina-1beta/metabolismo , Leishmania/fisiologia , Leishmania/virologia , Leishmaniose Mucocutânea/parasitologia , Leishmaniose Mucocutânea/virologia , Macrófagos/imunologia , Camundongos , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Vírus de RNA/fisiologia , Transdução de Sinais/imunologia , Receptor 3 Toll-Like/metabolismoRESUMO
The aim of this study was to evaluate the immunomodulatory effects of two toxins from Bothrops snake venoms (the P-I metalloprotease Batroxase and the thrombin-like serine protease Moojase) on human peripheral blood mononuclear cells (PBMC), also investigating changes in the expression of genes related to epigenetic alterations and their immunotherapeutic potential. After 24â¯h of PBMC stimulation, Batroxase (2⯵g/mL) and Moojase (4⯵g/mL) increased some cytokine levels (including IL-6 and IL-10), but did not promote cell death processes (apoptosis/necrosis) or alterations in the global DNA methylation levels. Gene expression experiments (RT-qPCR) showed that most of the genes with altered transcript levels encode enzymes that act on histones, such as acetyltransferases (HAT1), deacetylases (HDACs), methyltransferases (DOT1L) or demethylases (KDM5B), indicating that these toxins may alter gene regulation through epigenetic changes mainly related to histones and to methyl-CpG binding proteins (MECP2). Subsequently, the immunotherapeutic potential of these toxins was evaluated using in vitro cytotoxicity assays with NK cells and K562 leukemic cells. Both toxins were able to potentiate the NK cell cytotoxic effects against K562 tumor cells, and the effect of Batroxase was dependent on the concomitant stimulus with IL-2, whereas Moojase increased the NK cytotoxicity independently of IL-2. Thus, Batroxase and Moojase presented interesting immunomodulatory effects that could be explored for the development of new strategies in anticancer immunotherapies.
Assuntos
Venenos de Crotalídeos/toxicidade , Fatores Imunológicos/toxicidade , Leucócitos Mononucleares/efeitos dos fármacos , Metaloproteases/toxicidade , Proteínas de Répteis/toxicidade , Adulto , Animais , Bothrops , Sobrevivência Celular , Citocinas/metabolismo , Epigênese Genética/efeitos dos fármacos , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Células K562 , Células Matadoras Naturais , Leucócitos Mononucleares/metabolismo , Masculino , Adulto JovemRESUMO
The endoplasmic reticulum (ER) stress and inflammation relationship occurs at different levels and is essential for the adequate homeostatic function of cellular systems, becoming harmful when chronically engaged. Intense physical exercise enhances serum levels of interleukin 6 (IL-6). In response to a chronic exhaustive physical exercise protocol, our research group verified an increase of the IL-6 concentration and ER stress proteins in extensor digitorium longus (EDL) and soleus. Based on these results, we hypothesized that IL-6-knockout mice would demonstrate a lower modulation in the ER stress proteins compared to the wild-type mice. To clarify the relationship between exercise-induced IL-6 increased and ER stress, we studied the effects of an acute exhaustive physical exercise protocol on the levels of ER stress proteins in the skeletal muscles of IL-6-knockout (KO) mice. The WT group displayed a higher exhaustion time compared to the IL-6 KO group. After 1 h of the acute exercise protocol, the serum levels of IL-6 and IL-10 were enhanced in the WT group. Independent of the experimental group, the CHOP and cleaved caspase 12/total caspase 12 ratio in EDL as well as ATF6 and CHOP in soleus were sensitive to the acute exercise protocol. Compared to the WT group, the oscillation patterns over time of BiP in EDL and soleus as well as of peIF2-alpha/eIF2-alpha ratio in soleus were attenuated for the IL-6 KO group. In conclusion, IL-6 seems to be related with the ER stress homeostasis, once knockout mice presented attenuation of BiP in EDL and soleus as well as of pEiF2-alpha/EiF2-alpha ratio in soleus after the acute exhaustive physical exercise protocol.
Assuntos
Estresse do Retículo Endoplasmático/fisiologia , Interleucina-6/metabolismo , Músculo Esquelético/metabolismo , Condicionamento Físico Animal/fisiologia , Fator 6 Ativador da Transcrição/metabolismo , Animais , Western Blotting , Caspases/metabolismo , Estresse do Retículo Endoplasmático/genética , Interleucina-10/sangue , Interleucina-10/metabolismo , Interleucina-6/sangue , Interleucina-6/genética , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fator de Transcrição CHOP/metabolismoRESUMO
Infection with Schistosoma mansoni causes a chronic parasitic disease that progress to severe liver and gastrointestinal damage, and eventually death. During its development into mammalian hosts, immature schistosomula transit through the lung vasculature before they reach the liver to mature into adult worms. A low grade inflammatory reaction is induced during this process. However, molecules that are required for efficient leukocyte accumulation in the lungs of S. mansoni-infected subjects are unknown. In addition, specific leukocyte subsets that mediate pulmonary response during S. mansoni migration through the lung remain to be elucidated. ß2 integrins are fundamental regulators of leukocyte trans-endothelial migration and function. Therefore, we investigated their role during experimental schistosomiasis. Mice that express low levels of CD18 (the common ß2 integrin subunit) and wild type C57BL/6 mice were subcutaneously infected with S. mansoni cercariae. Cellular profiles of lungs and livers were evaluated in different time points after infection by flow cytometry. Low levels of CD18 affected the accumulation of patrolling Ly6Clow, intermediate Ly6Cinter monocytes, monocyte-derived macrophages and monocyte-derived dendritic cells in the lungs 7 days after infection. This correlated with increased TNF-α levels. Strikingly, low CD18 expression resulted in monocytopenia both in the peripheral blood and bone marrow during acute infection. After 48 days, S. mansoni worm burdens were higher in the hepatic portal system of CD18low mice, which also displayed reduced hepatic accumulation of patrolling Ly6Clow and intermediate Ly6Cinter, but not inflammatory Ly6Chigh monocytes. Higher parasite burden resulted in increased granulomatous lesions in the liver, increased egg deposition and enhanced mortality. Overall, our data point for a fundamental role of CD18 for monocyte hematopoiesis during infection, which promotes an efficient host response against experimental schistosomiasis.
Assuntos
Antígenos CD18/metabolismo , Leucócitos Mononucleares/fisiologia , Pulmão/imunologia , Schistosoma mansoni/fisiologia , Esquistossomose mansoni/imunologia , Animais , Antígenos Ly/metabolismo , Antígenos CD18/genética , Movimento Celular , Resistência à Doença , Hematopoese , Humanos , Imunidade Inata , Pulmão/parasitologia , Ativação Linfocitária , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Modelos Animais , Mutação/genética , Contagem de Ovos de ParasitasRESUMO
Monocytes are key cells in the immune dysregulation observed during human immunodeficiency virus (HIV) infection. The events that take place specifically in monocytes may contribute to the systemic immune dysfunction characterized by excessive immune activation in infected individuals, which directly correlates with pathogenesis and progression of the disease. Here, we investigated the immune dysfunction in monocytes from untreated and treated HIV + patients and associated these findings with epigenetic changes. Monocytes from HIV patients showed dysfunctional ability of phagocytosis and killing, and exhibited dysregulated cytokines and reactive oxygen species production after M. tuberculosis challenge in vitro. In addition, we showed that the expression of enzymes responsible for epigenetic changes was altered during HIV infection and was more prominent in patients that had high levels of soluble CD163 (sCD163), a newly identified plasmatic HIV progression biomarker. Among the enzymes, histone acetyltransferase 1 (HAT1) was the best epigenetic biomarker correlated with HIV - sCD163 high patients. In conclusion, we confirmed that HIV impairs effector functions of monocytes and these alterations are associated with epigenetic changes that once identified could be used as targets in therapies aiming the reduction of the systemic activation state found in HIV patients.
Assuntos
Epigênese Genética , Infecções por HIV/genética , Infecções por HIV/imunologia , HIV-1/fisiologia , Monócitos/imunologia , Adolescente , Adulto , Idoso , Antígenos CD/metabolismo , Antígenos de Diferenciação Mielomonocítica/metabolismo , Progressão da Doença , Ativação Enzimática , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Monócitos/metabolismo , Fagocitose/genética , Receptores de Superfície Celular/metabolismo , Adulto JovemRESUMO
Snake venoms are complex mixtures of organic and inorganic compounds, including proteins belonging to the protease (serine and metalloproteinases), oxidase (L-amino acid oxidases), and phospholipase (especially phospholipases A2) enzyme classes. These toxins account for the serious deleterious effects of snake envenomations, such as tissue necrosis, neurotoxicity, and hemorrhage. In addition to their toxic effects, snake venom toxins have served as important tools for investigating the mechanisms underlying envenomation and discovering new pharmacologically active compounds with immunotherapeutic potential. In this sense, the present review discusses the new findings and therapeutic perspectives in the immune modulating potential of enzymatic toxins from snake venoms belonging to the classes metalloproteinase, serine protease, L-amino acid oxidase, and phospholipase A2.
Assuntos
Enzimas/química , Enzimas/metabolismo , Venenos de Serpentes/química , Venenos de Serpentes/enzimologia , Toxinas Biológicas/química , Toxinas Biológicas/metabolismo , Animais , Enzimas/imunologia , Humanos , Imunomodulação , Mordeduras de Serpentes/imunologia , Mordeduras de Serpentes/metabolismo , Mordeduras de Serpentes/patologia , Mordeduras de Serpentes/terapia , Venenos de Serpentes/imunologia , Venenos de Serpentes/uso terapêutico , Toxinas Biológicas/imunologiaRESUMO
Overtraining (OT) may be defined as an imbalance between excessive training and adequate recovery period. Recently, a downhill running-based overtraining (OTR/down) protocol induced the nonfunctional overreaching state, which is defined as a performance decrement that may be associated with psychological and hormonal disruptions and promoted intramuscular and systemic inflammation. To discriminate the eccentric contraction effects on interleukin 1beta (IL-1ß), IL-6, IL-10, IL-15, and SOCS-3, we compared the release of these cytokines in OTR/down with other two OT protocols with the same external load (i.e., the product between training intensity and volume), but performed in uphill (OTR/up) and without inclination (OTR). Also, we evaluated the effects of these OT models on the muscle morphology and fiber type composition, serum levels of fatigue markers and corticosterone, as well as androgen receptor (AR) and glucocorticoid receptor (GR) expressions. For extensor digitorum longus (EDL), OTR/down and OTR groups increased the cytokines and exhibited micro-injuries with polymorphonuclear infiltration. While OTR/down group increased the cytokines in soleus muscle, OTR/up group only increased IL-6. All OT groups presented micro-injuries with polymorphonuclear infiltration. In serum, while OTR/down and OTR/up protocols increased IL-1ß, IL-6, and tumor necrosis factor alpha, OTR group increased IL-1ß, IL-6, IL-15, and corticosterone. The type II fibers in EDL and soleus, total and phosphorylated AR levels in soleus, and total GR levels in EDL and soleus were differentially modulated by the OT protocols. In summary, the proinflammatory cytokines were more sensitive for OTR/down than for OTR/up and OTR. Also, the specific treadmill inclination of each OT model influenced most of the other evaluated parameters.
RESUMO
Snake venom toxins that activate coagulation factors are key players in the process of venom-induced coagulopathy, and account for severe clinical manifestations. The present study applies a variety of biochemical, hematological, and histopathological approaches to broadly investigate the intravascular and systemic effects of moojenactivase (MooA), the first described PIIId subclass metalloprotease isolated from Bothrops sp. venom that activates coagulation factors. MooA induced consumption coagulopathy with high toxic potency, characterized by prolongation of prothrombin and activated partial thromboplastin time, consumption of fibrinogen and the plasma coagulation factors X and II, and thrombocytopenia. MooA promoted leukocytosis and expression of the proinflammatory cytokines interleukin-6 and tumor necrosis factor-α, accompanied by tissue factor-dependent procoagulant activity in peripheral blood mononuclear cells. This metalloprotease also caused intravascular hemolysis, elevated plasma levels of creatine kinase-MB, aspartate transaminase, and urea/creatinine, and induced morphopathological alterations in erythrocytes, heart, kidney, and lungs associated with thrombosis and hemorrhage. Diagnosis of MooA-induced disseminated intravascular coagulation represents an important approach to better understand the pathophysiology of Bothrops envenomation and develop novel therapeutic strategies targeting hemostatic disturbances.
Assuntos
Coagulação Sanguínea/efeitos dos fármacos , Venenos de Crotalídeos/farmacologia , Coagulação Intravascular Disseminada/induzido quimicamente , Coagulação Intravascular Disseminada/fisiopatologia , Metaloendopeptidases/farmacologia , Venenos de Serpentes/enzimologia , Animais , Biomarcadores/sangue , Coagulação Intravascular Disseminada/sangue , Coagulação Intravascular Disseminada/metabolismo , Relação Dose-Resposta a Droga , Eritrócitos/efeitos dos fármacos , Masculino , Ratos , Ratos Wistar , Fatores de TempoRESUMO
Oral tolerance (OT) is characterized as a peripheral immune tolerance form, in which, mature lymphocytes in lymphoid tissues associated with mucosa, become non-functional or hypo responsive due to prior oral administration of antigen. OT is an important immunological phenomenon due to its therapeutic potential in inflammatory processes and others diseases. Here we evaluated leukotriene role in the induction of OT, as well as, the production of cytokines IL-5 and IFN-γ in leukotriene deficient animals (knock-out). Our results suggested that even in the presence of OT and leukotrienes absence, cytokine IFN-γ remains being secreted, which gives us an indication of immune system specificity and also that IFN-γ participates in various immune processes.