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1.
Nat Prod Res ; 36(5): 1337-1341, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33380215

RESUMO

Tuberculosis (TB) remains a worldwide public health threat because of the emergence of resistant strains and subsequent inappropriate response to current therapy. We have been studying the restinga plants' antimycobacterial and anti-inflammatory potential. Dichloromethane fraction (DCM) from Vitex polygama Cham. showed high activity against Mycobacterium tuberculosis (Mtb) H37Rv. In this context, DCM fraction and isolated compounds were investigated against Mtb H37Rv and M299 (MDR strain) and for their immunomodulatory and cytotoxicity actions. Orientin showed the best antimycobacterial effect against Mtb M299 MDR strain (MIC50 15.4 ± 1.6 µg/mL), capacity of inhibiting NO production by macrophages (IC50 6.5 ± 1.2 µg/mL) and no significant cytotoxicity. The antimycobacterial effect of orientin was also observed on Mtb H37Rv intracellular growth in RAW 264.7 macrophages (MIC50 3.5 ± 1.1 and MIC90 9.1 ± 1.0 µg/mL). This is the first report describing the antimycobacterial effect of orientin, in both extra- and intracellular growth.[Formula: see text].


Assuntos
Produtos Biológicos , Mycobacterium tuberculosis , Vitex , Anti-Inflamatórios/farmacologia , Antituberculosos/farmacologia , Produtos Biológicos/farmacologia , Testes de Sensibilidade Microbiana
2.
Bioorg Med Chem ; 53: 116506, 2022 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-34890996

RESUMO

Tuberculosis (TB) remains a serious public health problem and one of the main concern is the emergence of multidrug-resistant and extensively resistant TB. Hyper-reactive patients develop inflammatory necrotic lung lesions that aggravate the pathology and facilitate transmission of mycobacteria. Treatment of severe TB is a major clinical challenge that has few effective solutions and patients face a poor prognosis, years of treatment and different adverse drug reactions. In this work, fifteen novel and thirty-one unusual thiourea derivatives were synthesized and evaluated in vitro for their antimycobacterial and anti-inflammatory potential and, in silico for ADMET parameters and for structure-activity relationship (SAR). Thioureas derivatives 10, 15, 16, 28 and 29 that had shown low cytotoxicity and high activities were selected for further investigation, after SAR study. These five thioureas derivatives inhibited Mtb H37Rv growth in bacterial culture and in infected macrophages, highlighting thiourea derivative 28 (MIC50 2.0 ± 1.1 and 2.3 ± 1.1 µM, respectively). Moreover, these compounds were active against the hypervirulent clinical Mtb strain M299, in bacterial culture, especially 16, 28 and 29, and in extracellular clumps, highlighting 29, with MIC50 5.6 ± 1.2 µM. Regarding inflammation, they inhibited NO through the suppression of iNOS expression, and also inhibited the production of TNF-α and IL-1ß. In silico studies were carried out suggesting that these five compounds could be administered by oral route and have low toxicological effects when compared to rifampicin. In conclusion, our data show that, at least, thiourea derivatives 16, 28 and 29 are promising antimycobacterial and anti-inflammatory agents, and candidates for further prospective studies aiming new anti-TB drugs, that can be used on a dual approach for the treatment of severe TB cases associated with exacerbated inflammation.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Antituberculosos/farmacologia , Mycobacterium tuberculosis/efeitos dos fármacos , Tioureia/farmacologia , Tuberculose Pulmonar/tratamento farmacológico , Anti-Inflamatórios não Esteroides/síntese química , Anti-Inflamatórios não Esteroides/química , Antituberculosos/síntese química , Antituberculosos/química , Relação Dose-Resposta a Droga , Humanos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Índice de Gravidade de Doença , Relação Estrutura-Atividade , Tioureia/síntese química , Tioureia/química , Tuberculose Pulmonar/microbiologia
3.
J Pharm Pharmacol ; 74(3): 446-457, 2022 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-34850064

RESUMO

OBJECTIVES: This study aimed to evaluate endophytic fungi isolated from Tocoyena bullata and Humiria balsamifera plant species for their antimycobacterial and anti-inflammatory activities, focusing on severe pulmonary tuberculosis cases which are often associated with exacerbated inflammation. METHODS: Mycobacterium suspensions were incubated with the samples for 5 days. RAW 264.7 macrophages stimulated with LPS were also incubated with them for 24 h to assess the inhibition of inflammatory mediator production and cytotoxicity. C57BL/6 mice were infected with Mtb M299 and treated for 15 days with lasiodiplodin (Lasio). KEY FINDINGS: Endophytic fungus Sordaria tamaensis, obtained from T. bullata, was the most promising. Its ethanolic extract impaired mycobacterial growth with MIC50 (µg/ml): 1.5 ± 0.6 (BCG), 66.8 ± 0.1 (H37Rv) and 80.0 ± 0.1 (M299). (R)-(+)-Lasio showed MIC50 92.2 ± 1.8 µg/ml (M299). In addition, Lasio was able to inhibit NO, IL-1ß and TNF-α production and was not cytotoxic for macrophages. M. tuberculosis-infected C57BL/6 animals treated by Lasio reduced the number of acid-fast bacilli, lung pathology, leucocyte influx and proinflammatory cytokine production in the lungs. The class IIa fructose 1,6-bisphosphate aldolase was the predicted hypothetical target of Lasio. CONCLUSIONS: (R)-(+)-Lasio stood out as a promising anti-TB compound, exhibiting anti-inflammatory and antimycobacterial effects, as well as low cytotoxicity.


Assuntos
Anti-Inflamatórios/farmacologia , Antituberculosos/farmacologia , Sordariales/química , Zearalenona/análogos & derivados , Animais , Anti-Inflamatórios/isolamento & purificação , Antituberculosos/isolamento & purificação , Células CACO-2 , Humanos , Inflamação/tratamento farmacológico , Lipopolissacarídeos , Macrófagos/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Mycobacterium tuberculosis/efeitos dos fármacos , Células RAW 264.7 , Rubiaceae/microbiologia , Sordariales/isolamento & purificação , Tuberculose Pulmonar/tratamento farmacológico , Tuberculose Pulmonar/microbiologia , Zearalenona/isolamento & purificação , Zearalenona/farmacologia
4.
Front Microbiol ; 12: 718477, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34504483

RESUMO

Among non-tuberculous mycobacteria, Mycobacterium kansasii is one of the most pathogenic, able to cause pulmonary disease indistinguishable from tuberculosis in immunocompetent susceptible adults. The lack of animal models that reproduce human-like lung disease, associated with the necrotic lung pathology, impairs studies of M. kansasii virulence and pathogenicity. In this study, we examined the ability of the C57BL/6 mice, intratracheally infected with highly virulent M. kansasii strains, to produce a chronic infection and necrotic lung pathology. As a first approach, we evaluated ten M. kansasii strains isolated from Brazilian patients with pulmonary disease and the reference strain M. kansasii ATCC 12478 for virulence-associated features in macrophages infected in vitro; five of these strains differing in virulence were selected for in vivo analysis. Highly virulent isolates induced progressive lung disease in mice, forming large encapsulated caseous granulomas in later stages (120-150 days post-infection), while the low-virulent strain was cleared from the lungs by day 40. Two strains demonstrated increased virulence, causing premature death in the infected animals. These data demonstrate that C57BL/6 mice are an excellent candidate to investigate the virulence of M. kansasii isolates. We observed considerable heterogeneity in the virulence profile of these strains, in which the presence of highly virulent strains allowed us to establish a clinically relevant animal model. Comparing public genomic data between Brazilian isolates and isolates from other geographic regions worldwide demonstrated that at least some of the highly pathogenic strains isolated in Brazil display remarkable genomic similarities with the ATCC strain 12478 isolated in the United States 70 years ago (less than 100 SNPs of difference), as well as with some recent European clinical isolates. These data suggest that few pathogenic clones have been widely spread within M. kansasii population around the world.

5.
Front Cell Infect Microbiol ; 11: 672472, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34026666

RESUMO

The risk of developing severe forms of tuberculosis has increased by the acquired immunodeficiency syndrome (AIDS) epidemic, lack of effective drugs to eliminate latent infection and the emergence of drug-resistant mycobacterial strains. Excessive inflammatory response and tissue damage associated with severe tuberculosis contribute to poor outcome of the disease. Our previous studies using mice deficient in the ATP-gated ionotropic P2X7 receptor suggested this molecule as a promising target for host-directed therapy in severe pulmonary tuberculosis. In this study, we assessed the effects of P2X7 pharmacological blockade on disease severity. First, we observed an increase in P2RX7 gene expression in the peripheral blood of tuberculosis patients compared to healthy donors. Lung leukocytes of mice infected with hypervirulent mycobacteria also showed increased expression of the P2X7 receptor. P2X7 blockade in mice with advanced tuberculosis recapitulated in many aspects the disease in P2X7-deficient mice. P2X7-directed therapy reduced body weight loss and the development of inflammatory and necrotic lung lesions, as well as delayed mycobacterial growth. Lower TNF-α production by lung cells and a substantial reduction in the lung GR-1+ myeloid cell population were observed after P2X7 inhibition. The effector CD4+ T cell population also decreased, but IFN-γ production by lung cells increased. The presence of a large population with characteristics of myeloid dendritic cells, as well as the increase in IL-6 production by lung cells, also indicate a qualitative improvement in the pulmonary immune response due to P2X7 inhibition. These findings support the use of drugs that target the P2X7 receptor as a therapeutic strategy to improve the outcome of pulmonary tuberculosis.


Assuntos
Pneumonia , Tuberculose Pulmonar , Tuberculose , Animais , Humanos , Pulmão , Camundongos , Camundongos Endogâmicos C57BL , Necrose , Receptores Purinérgicos P2X7
6.
J Infect Dis ; 223(3): 494-507, 2021 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-33206171

RESUMO

BACKGROUND: The role of myeloid-derived suppressor cells (MDSCs) in patients with severe tuberculosis who suffer from uncontrolled pulmonary inflammation caused by hypervirulent mycobacterial infection remains unclear. METHODS: This issue was addressed using C57BL/6 mice infected with highly virulent Mycobacterium bovis strain MP287/03. RESULTS: CD11b+GR1int population increased in the bone marrow, blood and lungs during advanced disease. Pulmonary CD11b+GR1int (Ly6GintLy6Cint) cells showed granularity similar to neutrophils and expressed immature myeloid cell markers. These immature neutrophils harbored intracellular bacilli and were preferentially located in the alveoli. T-cell suppression occurred concomitantly with CD11b+GR1int cell accumulation in the lungs. Furthermore, lung and bone marrow GR1+ cells suppressed both T-cell proliferation and interferon γ production in vitro. Anti-GR1 therapy given when MDSCs infiltrated the lungs prevented expansion and fusion of primary pulmonary lesions and the development of intragranulomatous caseous necrosis, along with increased mouse survival and partial recovery of T-cell function. Lung bacterial load was reduced by anti-GR1 treatment, but mycobacteria released from the depleted cells proliferated extracellularly in the alveoli, forming cords and clumps. CONCLUSIONS: Granulocytic MDSCs massively infiltrate the lungs during infection with hypervirulent mycobacteria, promoting bacterial growth and the development of inflammatory and necrotic lesions, and are promising targets for host-directed therapies.


Assuntos
Granulócitos , Pulmão/metabolismo , Mycobacterium bovis , Células Supressoras Mieloides , Tuberculose , Animais , Antígenos Ly , Medula Óssea , Antígeno CD11b , Proliferação de Células , Modelos Animais de Doenças , Granulócitos/imunologia , Imunomodulação , Pulmão/patologia , Camundongos , Camundongos Endogâmicos C57BL , Mycobacterium bovis/patogenicidade , Células Mieloides , Células Supressoras Mieloides/imunologia , Células Supressoras Mieloides/patologia , Neutrófilos , Tuberculose/patologia
7.
J Infect Dis ; 219(6): 964-974, 2019 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-30307561

RESUMO

BACKGROUND: Tuberculous pneumonia, necrotic granulomatous lesions, and bacterial dissemination characterize severe forms of mycobacterial infection. METHODS: To evaluate the pulmonary CD4+ T-cell response during severe tuberculosis, C57BL/6 mice were infected with approximately 100 bacilli of 3 hypervirulent mycobacterial isolates (Mycobacterium tuberculosis strain Beijing 1471 and Mycobacterium bovis strains B2 and MP287/03) or the H37Rv M tuberculosis strain as reference for mycobacterial virulence. Because high expression of both CD39 and CD73 ectonucleotidases was detected on parenchymal CD4+ T cells, we investigated whether CD4+ T-cell suppression in the context of severe disease was due to the extracellular adenosine accumulation that resulted from tissue damage. RESULTS: Lowest expression of CD69, which is an activation marker implicated in maintaining cells in tissues, was observed in lungs from mice displaying the most severe pulmonary pathology. Reduced interferon (IFN)γ-producing CD4+ T cells were also found in the lung of these mice. Intranasal administration of the adenosine receptor antagonist caffeine substantially enhanced the frequency and number of parenchymal CD4+ T cells as well as both CD69 expression and IFNγ production. CONCLUSIONS: These results indicate that adenosine, which may be generated by extracellular adenosine triphosphate degradation, impairs the parenchymal CD4+ T-cell response and contributes to the development of severe tuberculosis.


Assuntos
Linfócitos T CD4-Positivos/patologia , Pulmão/patologia , Tuberculose Pulmonar/patologia , 5'-Nucleotidase/metabolismo , Animais , Antígenos CD/metabolismo , Antígenos de Diferenciação de Linfócitos T/metabolismo , Cafeína/farmacologia , Interferon gama/metabolismo , Lectinas Tipo C/metabolismo , Pulmão/microbiologia , Camundongos Endogâmicos C57BL , Mycobacterium bovis/patogenicidade , Mycobacterium tuberculosis/patogenicidade , Antagonistas de Receptores Purinérgicos P1/farmacologia , Receptores Purinérgicos P1/metabolismo , Transdução de Sinais , Tuberculose Pulmonar/microbiologia
8.
Pathog Dis ; 76(6)2018 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-30053011

RESUMO

Paratuberculosis (PTB) or Johne's disease is a chronic intestinal infection of ruminants, caused by Mycobacterium avium subsp. paratuberculosis. The shedding of mycobacteria in the feces starts at the initial stages and increases with disease progression, suggesting that antigens secreted by mycobacteria could be excreted in the feces. Previously, we demonstrated that the alanine and proline-rich antigen (Apa), a secretory antigen of Map, could be detected in the intestine of cows with PTB using a monoclonal antibody. In this study, we verified whether this protein can be found in consistently detectable levels in the feces of cattle with PTB. Feces were obtained from cows with Johne's disease confirmed by laboratory tests, cows with suspected PTB based on seropositivity and from PTB-free control cows. Samples were immunoprecipitated using anti-Apa monoclonal antibody and analyzed by immunoblot. The Apa was detected as a 60/70 kDa doublet band in all samples obtained from animals with laboratory-confirmed disease and in a substantial proportion of seropositive asymptomatic animals, but not in the control samples. Additionally, the antigen was detected in the feces of animals with Johne's disease by ELISA. This study strongly suggests that Apa is a potential fecal biomarker of Johne's disease that could serve for immunodiagnosis.


Assuntos
Antígenos de Bactérias/análise , Proteínas de Bactérias/análise , Biomarcadores/análise , Doenças dos Bovinos/diagnóstico , Fezes/química , Mycobacterium avium subsp. paratuberculosis/química , Paratuberculose/diagnóstico , Animais , Bovinos , Doenças dos Bovinos/patologia , Ensaio de Imunoadsorção Enzimática , Fezes/microbiologia , Immunoblotting , Paratuberculose/patologia
11.
Pathog Dis, v. 76, n. 6, fty063, ago. 2018
Artigo em Inglês | Sec. Est. Saúde SP, SESSP-IBPROD, Sec. Est. Saúde SP | ID: bud-2633

RESUMO

Paratuberculosis (PTB) or Johne's disease is a chronic intestinal infection of ruminants, caused by Mycobacterium avium subsp. paratuberculosis. The shedding of mycobacteria in the feces starts at the initial stages and increases with disease progression, suggesting that antigens secreted by mycobacteria could be excreted in the feces. Previously, we demonstrated that the alanine and proline-rich antigen (Apa), a secretory antigen of Map, could be detected in the intestine of cows with PTB using a monoclonal antibody. In this study, we verified whether this protein can be found in consistently detectable levels in the feces of cattle with PTB. Feces were obtained from cows with Johne's disease confirmed by laboratory tests, cows with suspected PTB based on seropositivity and from PTB-free control cows. Samples were immunoprecipitated using anti-Apa monoclonal antibody and analyzed by immunoblot. The Apa was detected as a 60/70 kDa doublet band in all samples obtained from animals with laboratory-confirmed disease and in a substantial proportion of seropositive asymptomatic animals, but not in the control samples. Additionally, the antigen was detected in the feces of animals with Johne's disease by ELISA. This study strongly suggests that Apa is a potential fecal biomarker of Johne's disease that could serve for immunodiagnosis.

12.
Pathog Dis ; 76(6): fty063, 2018.
Artigo em Inglês | Sec. Est. Saúde SP, SESSP-IBPROD, Sec. Est. Saúde SP | ID: but-ib15751

RESUMO

Paratuberculosis (PTB) or Johne's disease is a chronic intestinal infection of ruminants, caused by Mycobacterium avium subsp. paratuberculosis. The shedding of mycobacteria in the feces starts at the initial stages and increases with disease progression, suggesting that antigens secreted by mycobacteria could be excreted in the feces. Previously, we demonstrated that the alanine and proline-rich antigen (Apa), a secretory antigen of Map, could be detected in the intestine of cows with PTB using a monoclonal antibody. In this study, we verified whether this protein can be found in consistently detectable levels in the feces of cattle with PTB. Feces were obtained from cows with Johne's disease confirmed by laboratory tests, cows with suspected PTB based on seropositivity and from PTB-free control cows. Samples were immunoprecipitated using anti-Apa monoclonal antibody and analyzed by immunoblot. The Apa was detected as a 60/70 kDa doublet band in all samples obtained from animals with laboratory-confirmed disease and in a substantial proportion of seropositive asymptomatic animals, but not in the control samples. Additionally, the antigen was detected in the feces of animals with Johne's disease by ELISA. This study strongly suggests that Apa is a potential fecal biomarker of Johne's disease that could serve for immunodiagnosis.

13.
Rev. bras. farmacogn ; 27(6): 702-710, Nov.-Dec. 2017. tab, graf
Artigo em Inglês | LILACS | ID: biblio-898725

RESUMO

ABSTRACT In general, Passiflora species have been reported for their folk medicinal use as sedative and anti-inflammatory. However, P. caerulea has already been reported to treat pulmonary diseases. Severe pulmonary tuberculosis, generally caused by Mycobacterium tuberculosis strains resistant to multiple drugs, can lead to deleterious inflammation and high mortality, encouraging new approaches in drug discovery. Thus, the aim of this work was to evaluate the Passiflora mucronata Lam., Passifloraceae, potential for tuberculosis treatment. Specifically, related to antimycobacterial activity and anti-inflammatory related effects (based on inhibition of nitric oxide, tumor necrosis factor-alpha production and antioxidant potential), as well as the chemical profile of P. mucronata. High performance liquid chromatography coupled with diode-array ultraviolet and mass spectrometer analyses of crude hydroalcoholic extract and ethyl acetate fraction showed the presence of flavonoids. Ethyl acetate fraction showed to be as antioxidant as Ginkgo biloba standard extract with EC50 of 14.61 ± 1.25 µg/ml. One major flavonoid isolated from ethyl acetate fraction was characterized as isoorientin. The hexane fraction and its main isolated compound, the triterpene β-amyrin, exhibited significant growth inhibitory activity against Mycobacterium bovis BCG (MIC50 1.61 ± 1.43 and 3.93 ± 1.05 µg/ml, respectively). In addition, Passiflora mucronata samples, specially hexane and dichloromethane fractions, as well as pure β-amyrin, showed a dose-related inhibition of lipopolysaccharide (LPS)-induced nitric oxide production. In conclusion, Passiflora mucronata presented relevant biological potential and should be considered for further studies using in vivo pulmonary tuberculosis model.

15.
Front Immunol ; 8: 435, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28450867

RESUMO

Tuberculosis (TB) remains a serious public health problem despite the great scientific advances in the recent decades. We have previously shown that aggressive forms of TB caused by hypervirulent strains of Mycobacterium tuberculosis and Mycobacterium bovis are attenuated in mice lacking the P2X7 receptor, an ion channel activated by extracellular ATP. Therefore, P2X7 receptor is a potential target for therapeutic intervention. In vitro, hypervirulent mycobacteria cause macrophage death by a P2X7-dependent mechanism that facilitates bacillus dissemination. However, as P2X7 receptor is expressed in both bone marrow (BM)-derived cells and lung structural cells, several cellular mechanisms can operate in vivo. To investigate whether the presence of P2X7 receptor in BM-derived cells contributes to TB severity, we generated chimeric mice by adoptive transfer of hematopoietic cells from C57BL/6 or P2X7-/- mice into CD45.1 irradiated mice. After infection with hypervirulent mycobacteria (MP287/03 strain of M. bovis), P2X7-/->CD45.1 mice recapitulated the TB resistance observed in P2X7-/- mice. These chimeric mice showed lower lung bacterial load and attenuated pneumonia compared to C57BL/6>CD45.1 mice. Lung necrosis and bacterial dissemination to the spleen and liver were also reduced in P2X7-/->CD45.1 mice compared to C57BL/6>CD45.1 mice. Furthermore, an immature-like myeloid cell population showing a Ly6Gint phenotype was observed in the lungs of infected C57BL/6 and C57BL/6>CD45.1 mice, whereas P2X7-/- and P2X7-/->CD45.1 mice showed a typical neutrophil (Ly6Ghi) population. This study clearly demonstrates that P2X7 receptor in BM-derived cells plays a critical role in the progression of severe TB.

16.
PLoS One ; 12(3): e0173715, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28306733

RESUMO

Tuberculosis (TB) is a chronic infectious disease caused by Mycobacterium tuberculosis (Mtb) that in most cases induces irreversible necrosis of lung tissue as a result of excessive inflammatory reactions. The murine model of TB in resistant C57BL/6 mice infected with reference Mtb strains is widely used in TB studies; however, these mice do not show a necrotic pathology, which restricts their use in studies of irreversible tissue damage. Recently, we demonstrated that necrotic lung lesions could be induced in the C57BL/6 mice by highly virulent Mtb strains belonging to the modern Beijing sublineage. However, the pathogenic mechanisms leading to necrosis in this model were not elucidated. In this study, we investigated the dynamics of lung lesions in mice infected with highly virulent Beijing Mtb strain M299, compared with those infected with laboratory Mtb strain H37Rv. The data demonstrate that necrotic lung lesions in mice infected by the strain M299 were associated with enhanced recruitment of myeloid cells, especially neutrophils, and increased levels of proinflammatory cytokines, consistent with exacerbated inflammation. High levels of IFN-γ production contributed to the control of bacterial growth. Further progression to chronic disease was associated with a reduction in the levels of inflammatory mediators in the lungs, the accumulation of foamy macrophages and partial healing of the necrotic tissue by fibrosis. At a late stage of disease, degradation of foamy cells resulted in the liberation of accumulated lipids and persisting bacilli and further activation of inflammation, which promoted lung consolidation. Overall, our studies show that C57BL/6 mice infected with highly virulent Mtb strain may serve as a TB model reproducing an exacerbated inflammatory response in a resistant host to hypervirulent mycobacteria, leading to irreversible necrotic lung lesions.


Assuntos
Mycobacterium tuberculosis/patogenicidade , Neutrófilos/imunologia , Tuberculose Pulmonar/microbiologia , Animais , Citocinas/biossíntese , Camundongos , Camundongos Endogâmicos C57BL , Mycobacterium tuberculosis/crescimento & desenvolvimento , Tuberculose Pulmonar/metabolismo , Tuberculose Pulmonar/patologia , Virulência
17.
Front Immunol ; apr(8): 435-435, 2017.
Artigo em Inglês | Sec. Est. Saúde SP, SESSP-IDPCPROD, Sec. Est. Saúde SP | ID: biblio-1062897

RESUMO

Tuberculosis (TB) remains a serious public health problem despite the great scientific advances in the recent decades. We have previously shown that aggressive forms of TB caused by hypervirulent strains of Mycobacterium tuberculosis and Mycobacterium bovis are attenuated in mice lacking the P2X7 receptor, an ion channel activated by extracellular ATP. Therefore, P2X7 receptor is a potential target for therapeutic intervention. In vitro, hypervirulent mycobacteria cause macrophage death by a P2X7-dependent mechanism that facilitates bacillus dissemination. However, as P2X7 receptor is expressed in both bone marrow (BM)-derived cells and lung structural cells, several cellular mechanisms can operate in vivo. To investigate whether the presence of P2X7 receptor in BM-derived cells contributes to TB severity, we generated chimeric mice by adoptive transfer of hematopoietic cells from C57BL/6 or P2X7-/- mice into CD45.1 irradiated mice. After infection with hypervirulent mycobacteria (MP287/03 strain of M. bovis), P2X7-/->CD45.1 mice recapitulated the TB resistance observed in P2X7-/- mice. These chimeric mice showed lower lung bacterial load and attenuated pneumonia compared to C57BL/6>CD45.1 mice. Lung necrosis and bacterial dissemination to the spleen and liver were also reduced in P2X7-/->CD45.1 mice compared to C57BL/6>CD45.1 mice...


Assuntos
Células , Medula Óssea , Tuberculose
18.
Microbes Infect ; 18(1): 11-20, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26369715

RESUMO

The success of Mycobacterium tuberculosis as a human pathogen has been attributed to the ability of the bacillus to proliferate inside macrophages and to induce cell death. This review describes how the sensors of the innate immune system modulate the cell death pathways in infected macrophages and, consequently, the pathogenesis of tuberculosis.


Assuntos
Morte Celular , Imunidade Inata , Macrófagos/imunologia , Macrófagos/fisiologia , Mycobacterium tuberculosis/imunologia , Mycobacterium tuberculosis/patogenicidade , Tuberculose/patologia , Interações Hospedeiro-Patógeno , Humanos
19.
Genome Announc ; 3(5)2015 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-26430044

RESUMO

Mycobacterium tuberculosis of the Bejing subtype (MtbB) is transmitted efficiently in high burden countries for this genotype. A higher virulence was associated with isolates of the "modern" Beijing genotype sub-lineages when compared to "ancient" ones. Here, we report the full genomes of the strain representing these two genotypes from Brazil, a country with a low incidence of MtbB.

20.
Molecules ; 20(5): 8072-93, 2015 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-25951004

RESUMO

Tuberculosis (TB) remains a serious public health problem aggravated by the emergence of M. tuberculosis (Mtb) strains resistant to multiple drugs (MDR). Delay in TB treatment, common in the MDR-TB cases, can lead to deleterious life-threatening inflammation in susceptible hyper-reactive individuals, encouraging the discovery of new anti-Mtb drugs and the use of adjunctive therapy based on anti-inflammatory interventions. In this study, a series of forty synthetic chalcones was evaluated in vitro for their anti-inflammatory and antimycobacterial properties and in silico for pharmacokinetic parameters. Seven compounds strongly inhibited NO and PGE2 production by LPS-stimulated macrophages through the specific inhibition of iNOS and COX-2 expression, respectively, with compounds 4 and 5 standing out in this respect. Four of the seven most active compounds were able to inhibit production of TNF-α and IL-1ß. Chalcones that were not toxic to cultured macrophages were tested for antimycobacterial activity. Eight compounds were able to inhibit growth of the M. bovis BCG and Mtb H37Rv strains in bacterial cultures and in infected macrophages. Four of them, including compounds 4 and 5, were active against a hypervirulent clinical Mtb isolate as well. In silico analysis of ADMET properties showed that the evaluated chalcones displayed satisfactory pharmacokinetic parameters. In conclusion, the obtained data demonstrate that at least two of the studied chalcones, compounds 4 and 5, are promising antimycobacterial and anti-inflammatory agents, especially focusing on an anti-tuberculosis dual treatment approach.


Assuntos
Anti-Inflamatórios/farmacologia , Antituberculosos/farmacologia , Chalconas/farmacologia , Mycobacterium tuberculosis/efeitos dos fármacos , Tuberculose/tratamento farmacológico , Animais , Linhagem Celular , Ciclo-Oxigenase 2/metabolismo , Dinoprostona/metabolismo , Interleucina-1beta/metabolismo , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Óxido Nítrico Sintase Tipo II/metabolismo , Óxidos de Nitrogênio/metabolismo , Tuberculose/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
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