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1.
Public Health Action ; 13(4): 173-178, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38077720

RESUMO

SETTING: The diagnosis of Buruli ulcer (BU) is frequently made by experienced health workers in rural regions. This leads to long turnaround times to confirm the diagnosis as it requires specialised laboratory infrastructure to perform confirmatory testing. BACKGROUND: Given the lack of success with protein antigens to detect BU in human sera, the aim of this study was to evaluate a range of single synthetic lipid antigens using an enzyme-linked immunosorbent assay (ELISA). The ELISA system used was initially developed to detect TB using single synthetic lipid antigens. METHODS: Thirty polymerase chain reaction (PCR) positive BU samples and 30 PCR-negative healthy contact samples collected from Asante Akim North and Ahafo Ano North Districts, Ghana, that are endemic for BU between 2013 and 2016 were used to evaluate the synthetic lipid antigen ELISA. A Quantikine ELISA was also conducted on a randomly blinded sub-set of 30 samples. RESULTS: The synthetic lipid ELISA evaluated here outperforms all other ELISA tests using protein antigens to detect BU to date and has shown potential as a fast (2 h) test for BU which may be adapted for use at the point of care. A sensitivity of 63% and specificity of 80% was observed for 30 BU-positive and 30 BU-negative samples, with significantly reduced interleukin-8 (IL-8) levels in a subset of patients with BU. CONCLUSION: A single lipid was shown for the first time to have the ability to distinguish between PCR-positive BU and negative sera using ELISA. The low lipid antibody load detected may be a result of immune suppression caused by the presence of mycolactone in patients with BU, given that levels of IL-8 were significantly reduced in patients with BU compared to the control serum samples.

2.
ACS Appl Mater Interfaces ; 15(23): 27670-27686, 2023 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-37262346

RESUMO

An improved vaccine is urgently needed to replace the now more than 100-year-old Bacillus Calmette-Guérin (BCG) vaccine against tuberculosis (TB) disease, which represents a significant burden on global public health. Mycolic acid, or cord factor trehalose 6,6' dimycolate (TDM), a lipid component abundant in the cell wall of the pathogen Mycobacterium tuberculosis (MTB), has been shown to have strong immunostimulatory activity but remains underexplored due to its high toxicity and poor solubility. Herein, we employed a novel strategy to encapsulate TDM within a cubosome lipid nanocarrier as a potential subunit nanovaccine candidate against TB. This strategy not only increased the solubility and reduced the toxicity of TDM but also elicited a protective immune response to control MTB growth in macrophages. Both pre-treatment and concurrent treatment of the TDM encapsulated in lipid monoolein (MO) cubosomes (MO-TDM) (1 mol %) induced a strong proinflammatory cytokine response in MTB-infected macrophages, due to epigenetic changes at the promoters of tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6) in comparison to the untreated control. Furthermore, treatment with MO-TDM (1 mol %) cubosomes significantly improved antigen processing and presentation capabilities of MTB-infected macrophages to CD4 T cells. The ability of MO-TDM (1 mol %) cubosomes to induce a robust innate and adaptive response in vitro was further supported by a mathematical modeling study predicting the vaccine efficacy in vivo. Overall, these results indicate a strong immunostimulatory effect of TDM when delivered through the lipid nanocarrier, suggesting its potential as a novel TB vaccine.


Assuntos
Mycobacterium tuberculosis , Tuberculose , Humanos , Idoso de 80 Anos ou mais , Fatores Corda/farmacologia , Estudos Prospectivos , Tuberculose/tratamento farmacológico , Tuberculose/prevenção & controle , Citocinas
3.
Microb Genom ; 9(5)2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37171244

RESUMO

Lineage 7 (L7) emerged in the phylogeny of the Mycobacterium tuberculosis complex (MTBC) subsequent to the branching of 'ancient' lineage 1 and prior to the Eurasian dispersal of 'modern' lineages 2, 3 and 4. In contrast to the major MTBC lineages, the current epidemiology suggests that prevalence of L7 is highly confined to the Ethiopian population, or when identified outside of Ethiopia, it has mainly been in patients of Ethiopian origin. To search for microbiological factors that may contribute to its restricted distribution, we compared the genome of L7 to the genomes of globally dispersed MTBC lineages. The frequency of predicted functional mutations in L7 was similar to that documented in other lineages. These include mutations characteristic of modern lineages - such as constitutive expression of nitrate reductase - as well as mutations in the VirS locus that are commonly found in ancient lineages. We also identified and characterized multiple lineage-specific mutations in L7 in biosynthesis pathways of cell wall lipids, including confirmed deficiency of methoxy-mycolic acids due to a stop-gain mutation in the mmaA3 gene that encodes a methoxy-mycolic acid synthase. We show that the abolished biosynthesis of methoxy-mycolates of L7 alters the cell structure and colony morphology on selected growth media and impacts biofilm formation. The loss of these mycolic acid moieties may change the host-pathogen dynamic for L7 isolates, explaining the limited geographical distribution of L7 and contributing to further understanding the spread of MTBC lineages across the globe.


Assuntos
Mycobacterium tuberculosis , Humanos , Mycobacterium tuberculosis/genética , Ácidos Micólicos/metabolismo , Mutação , Filogenia , Etiópia/epidemiologia
4.
Elife ; 122023 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-36753434

RESUMO

The myeloid C-type lectin receptor (CLR) MINCLE senses the mycobacterial cell wall component trehalose-6,6'-dimycolate (TDM). Recently, we found that IL-4 downregulates MINCLE expression in macrophages. IL-4 is a hallmark cytokine in helminth infections, which appear to increase the risk for mycobacterial infection and active tuberculosis. Here, we investigated functional consequences of IL-4 and helminth infection on MINCLE-driven macrophage activation and Th1/Th17 adjuvanticity. IL-4 inhibited MINCLE and cytokine induction after macrophage infection with Mycobacterium bovis bacille Calmette-Guerin (BCG). Infection of mice with BCG upregulated MINCLE on myeloid cells, which was inhibited by IL-4 plasmid injection and by infection with the nematode Nippostrongylus brasiliensis in monocytes. To determine the impact of helminth infection on MINCLE-dependent immune responses, we vaccinated mice with a recombinant protein together with the MINCLE ligand trehalose-6,6-dibehenate (TDB) as adjuvant. Concurrent infection with N. brasiliensis or with Schistosoma mansoni promoted T cell-derived IL-4 production and suppressed Th1/Th17 differentiation in the spleen. In contrast, helminth infection did not reduce Th1/Th17 induction by TDB in draining peripheral lymph nodes, where IL-4 levels were unaltered. Upon use of the TLR4-dependent adjuvant G3D6A, N. brasiliensis infection impaired selectively the induction of splenic antigen-specific Th1 but not of Th17 cells. Inhibition of MINCLE-dependent Th1/Th17 responses in mice infected with N. brasiliensis was dependent on IL-4/IL-13. Thus, helminth infection attenuated the Th17 response to MINCLE-dependent immunization in an organ- and adjuvant-specific manner via the Th2 cytokines IL-4/IL-13. Taken together, our results demonstrate downregulation of MINCLE expression on monocytes and macrophages by IL-4 as a possible mechanism of thwarted Th17 vaccination responses by underlying helminth infection.


Assuntos
Interleucina-4 , Lectinas Tipo C , Proteínas de Membrana , Infecções por Strongylida , Animais , Camundongos , Adjuvantes Imunológicos , Vacina BCG , Citocinas/imunologia , Interleucina-13 , Interleucina-4/imunologia , Lectinas Tipo C/genética , Lectinas Tipo C/metabolismo , Macrófagos/imunologia , Mycobacterium bovis , Células Th1 , Células Th17/imunologia , Proteínas de Membrana/metabolismo , Nippostrongylus , Infecções por Strongylida/imunologia
5.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 43(3): 452-461, 2021 Jun 30.
Artigo em Chinês | MEDLINE | ID: mdl-34238423

RESUMO

The primary and secondary tuberculosis features two completely different pathogenesis.At present,the pathogenesis of primary tuberculosis has been clear,whereas that of secondary tuberculosis remains unclear.In order to decipher the mechanism of secondary infection of Mycobacterium tuberculosis and provide insights into vaccine research and drug development,this paper reviews the problems of the widely accepted mechanism of secondary infection,the new findings of the research on the mechanism,as well as the role of cord factors.


Assuntos
Coinfecção , Mycobacterium tuberculosis , Tuberculose Pulmonar , Tuberculose , Fatores Corda , Humanos
6.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-887879

RESUMO

The primary and secondary tuberculosis features two completely different pathogenesis.At present,the pathogenesis of primary tuberculosis has been clear,whereas that of secondary tuberculosis remains unclear.In order to decipher the mechanism of secondary infection of


Assuntos
Humanos , Coinfecção , Fatores Corda , Mycobacterium tuberculosis , Tuberculose , Tuberculose Pulmonar
7.
Tuberculosis (Edinb) ; 116S: S118-S122, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31072690

RESUMO

Mycobacterium tuberculosis (MTB) is a pathogen that infects and kills millions yearly. The mycobacterium's cell wall glycolipid trehalose 6,6'-dimycolate (TDM) has been used historically to model MTB induced inflammation and granuloma formation. Alterations to the model can significantly influence the induced pathology. One such method incorporates intraperitoneal pre-exposure, after which the intravenous injection of TDM generates pathological damage effectively mimicking the hypercoagulation, thrombus formation, and tissue remodeling apparent in lungs of infected individuals. The purpose of these experiments is to examine the histological inflammation involved in the TDM mouse model that induces development of the hemorrhagic response. TDM induced lungs of C57BL/6 mice to undergo granulomatous inflammation. Further histological examination of the peak response demonstrated tissue remodeling consistent with hypercoagulation. The observed vascular occlusion indicates that obstruction likely occurs due to subendothelial localized activity leading to restriction of blood vessel lumens. Trichrome staining revealed that associated damage in the hypercoagulation model is consistent with intra endothelial cell accumulation of innate cells, bordered by collagen deposition in the underlying parenchyma. Overall, the hypercoagulation model represents a comparative pathological instrument for understanding mechanisms underlying development of hemorrhage and vascular occlusion seen during MTB infection.


Assuntos
Fatores Corda/metabolismo , Endotélio Vascular/patologia , Granuloma do Sistema Respiratório/patologia , Pulmão/irrigação sanguínea , Mycobacterium tuberculosis/metabolismo , Pneumonia/patologia , Tuberculose Pulmonar/patologia , Animais , Coagulação Sanguínea , Modelos Animais de Doenças , Endotélio Vascular/microbiologia , Feminino , Granuloma do Sistema Respiratório/sangue , Granuloma do Sistema Respiratório/induzido quimicamente , Granuloma do Sistema Respiratório/microbiologia , Pulmão/microbiologia , Camundongos Endogâmicos C57BL , Pneumonia/sangue , Pneumonia/induzido quimicamente , Pneumonia/microbiologia , Tuberculose Pulmonar/sangue , Tuberculose Pulmonar/induzido quimicamente , Tuberculose Pulmonar/microbiologia , Remodelação Vascular
8.
Open Rheumatol J ; 12: 30-36, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29643949

RESUMO

INTRODUCTION: Suspicion on the association between Takayasu Arteritis (TA) and Tubcerculosis (TB) has been in vogue for years. Prevalence of TB in TA is reported to be higher. We aimed to study innate immune responses in patients with TA on exposure to Trehalose-6,6-dibehenate (TDB), a synthetic analogue of Trehalose-6,6-Dimycolate (TDM, also known as mycobacterial cord factor) in comparison with healthy controls. MATERIALS AND METHODS: Patients with type V TA, satisfying 1990 ACR criteria, and age and sex matched healthy controls were recruited. PBMCs were cultured with 5µg/ml, 50µg/ml or without any TDB for 48 hours in RPMI medium inside a 5% Co2 incubator. IL-6, TNF-α and IL-17 were measured in cell culture supernatant, which was separated from the cells at the end of the incubation period. Gene expressions of IL-6, IL-8, TNFα, IFN-γ, MINCLE and BCL-10 were quantified in real time PCR using specific primers and SYBR green chemistry. RESULTS: Twenty two TA patients and 21 healthy controls were recruited. Both patients and controls showed response by secreting IL-6 and TNF-α upon stimulation by TDB. Relative induction (TDB stimulated TA sample / unstimulated control) of IL-6 was significantly higher in TA [31.88(0.74-168)] patients as compared to healthy controls [1.931(0.644-8.21); p<0.002], when co-cultured with 50µg/ml TDB. The expression of MINCLE, the TDB receptor was higher in TA samples than healthy controls upon TDB stimulation. CONCLUSION: Stimulation with mycobacterial synthetic analogue led to higher secretion of IL-6 and higher expression of MINCLE in PBMCs of patients with TA as compared to healthy controls.

9.
Antonie Van Leeuwenhoek ; 111(5): 717-725, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29435693

RESUMO

Within the Actinobacteria, the genera Corynebacterium, Mycobacterium, Nocardia and Rhodococcus form the so-called CMNR group, also designated as mycolic acid-containing actinomycetes. Almost all members of this group are characterized by a mycolic acid layer, the mycomembrane, which covers the cell wall and is responsible for a high resistance of these bacteria against chemical and antibiotic stress. Furthermore, components of the mycomembrane are crucial for the interaction of bacteria with host cells. This review summarizes the current knowledge of mycolic acid synthesis and interaction with components of the immune system for the genus Corynebacterium with an emphasis on the pathogenic species Corynebacterium diphtheriae, Corynebacterium pseudotuberculosis and Corynebacterium ulcerans as well as the biotechnology workhorse Corynebacterium glutamicum.


Assuntos
Infecções por Corynebacterium/microbiologia , Corynebacterium/patogenicidade , Interações Hospedeiro-Patógeno/fisiologia , Ácidos Micólicos/metabolismo , Animais , Parede Celular/química , Corynebacterium/fisiologia , Infecções por Corynebacterium/imunologia , Glicolipídeos/imunologia , Humanos , Estrutura Molecular , Ácidos Micólicos/química , Ácidos Micólicos/imunologia
10.
Future Med Chem ; 9(12): 1345-1360, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28776416

RESUMO

Synthetic agonists of innate immune cells are of interest to immunologists due to their synthesis from well-defined materials, optimized activity, and monodisperse chemical purity. These molecules are used in both prophylactic and therapeutic contexts from vaccines to cancer immunotherapies. In this review we highlight synthetic agonists that activate innate immune cells through three classes of pattern recognition receptors: NOD-like receptors, RIG-I-like receptors, and C-type lectin receptors. We classify these agonists by the receptor they activate and present them from a chemical perspective, focusing on structural components that define agonist activity. We anticipate this review will be useful to the medicinal chemist as a guide to chemical motifs that activate each receptor, ultimately illuminating a chemical space ripe for exploration.


Assuntos
Inflamação/imunologia , Lectinas Tipo C/agonistas , Oligonucleotídeos/farmacologia , Bibliotecas de Moléculas Pequenas/farmacologia , Humanos , Imunidade Inata/efeitos dos fármacos , Imunidade Inata/imunologia , Inflamação/tratamento farmacológico , Lectinas Tipo C/imunologia , Estrutura Molecular , Oligonucleotídeos/síntese química , Oligonucleotídeos/química , Bibliotecas de Moléculas Pequenas/síntese química , Bibliotecas de Moléculas Pequenas/química
11.
Artigo em Português | LILACS, Sec. Est. Saúde SP, SESSP-ACVSES, SESSP-IALPROD, Sec. Est. Saúde SP, SESSP-IALACERVO | ID: biblio-982802

RESUMO

A OMS, em 2007, recomendou a implementação da cultura líquida para o diagnóstico da tuberculose (TB) e teste de sensibilidade para países de baixa e média renda. Neste estudo foi avaliado odesempenho da cultura líquida MGIT em condição de rotina após dois anos de implantação em uma rede de laboratórios públicos. Foi efetuada análise retrospectiva de dados da cultura líquida,realizadas em dez laboratórios regionais do Instituto Adolfo Lutz, de janeiro a março de 2010. Foram incluídas amostras submetidas a baciloscopia, cultura líquida MGIT automatizada ou manual eidentificação presuntiva do complexo Mycobacterium tuberculosis (CMTB). Foram detectadas 1.159 culturas positivas. Destas, 113 (9,7%) contaminaram, e 1.046 foram analisadas, sendo 850 (81,3%) CMTB, 116 (11,1%) micobactérias não tuberculosas e 6 (0,6%) Nocardia sp. A taxa de contaminação foi de 2,2% e o acréscimo da cultura para o diagnóstico da TB foi de 29,9%. A média do tempo de detecção da cultura foi de 14,7 dias (DP+/- 11,7 dias). A acurácia da identificação presuntiva foide 91,3%. A cultura líquida MGIT demonstrou ser excelente alternativa para efetuar diagnóstico da TB e das micobacterioses, em razão da rapidez possibilitando uma intervenção rápida e eficaz no tratamento.


In 2007, WHO recommended the implementation of liquid culture for tuberculosis (TB) diagnosis anddrug-susceptibility test in low and middle-income countries. This study evaluated the performanceof MGIT culture in routine condition after two years of its implementation in a public laboratoriesnetwork. This is a retrospective study, which analyzed the data on the liquid culture performed in ten regional laboratories of the Institute Adolfo Lutz, from January to March 2010. The data included clinical samples submitted to microscopy, automated or manual MGIT culture and presumptive M. tuberculosis complex (MTBC) identification by analyzing the cord formation. Culture waspositive in 1,159 samples. Of these, 113 (9.7%) contaminated, and 1,046 were analyzed, of which 850 (81.3%) were identified as MTBC, 116 (11.1%) as non-tuberculous mycobacteria and 6 (0.6%)as Nocardia sp. Contamination rate was 2.2% and the contribution of culture to the TB diagnosis was 29.9%. The detection mean time was 14.7 days (SD+/-11.7 days). The accuracy of the presumptive identification of MTBC was 91.3%. MGIT liquid culture demonstrated to be an excellent alternative for diagnosing TB and mycobacterioses, because of the rapidity of diagnosis, thus allowing an immediate and effective treatment.


Assuntos
Humanos , Fatores Corda , Mycobacterium tuberculosis , Serviços Laboratoriais de Saúde Pública , Tuberculose
12.
Artigo em Português | LILACS, VETINDEX | ID: biblio-1489555

RESUMO

A OMS, em 2007, recomendou a implementação da cultura líquida para o diagnóstico da tuberculose (TB) e teste de sensibilidade para países de baixa e média renda. Neste estudo foi avaliado o desempenho da cultura líquida MGIT em condição de rotina após dois anosde implantação em uma rede de laboratórios públicos. Foi efetuada análise retrospectiva de dados da cultura líquida, realizadas em dez laboratórios regionais do Instituto Adolfo Lutz, de janeiro a março de 2010. Foram incluídas amostras submetidas a baciloscopia, cultura líquida MGIT automatizada ou manual e identificação presuntiva do complexo Mycobacterium tuberculosis (CMTB). Foram detectadas 1.159 culturas positivas. Destas, 113 (9,7%) contaminaram, e 1.046 foram analisadas, sendo 850 (81,3%) CMTB, 116 (11,1%) micobactérias não tuberculosas e 6 (0,6%) Nocardia sp A taxa de contaminação foi de 2,2% e o acréscimo da cultura para o diagnóstico da TB foi de 29,9%. A média do tempo de detecção da cultura foi de 14,7 dias (DP+/- 11,7 dias). A acurácia da identificação presuntiva foi de 91,3%. A cultura líquida MGIT demonstrou ser excelente alternativa para efetuar diagnóstico da TB e das micobacterioses, em razão da rapidez possibilitando uma intervenção rápida e eficaz no tratamento.


In 2007, WHO recommended the implementation of liquid culture for tuberculosis (TB) diagnosis and drug-susceptibility test in low and middle-income countries. This study evaluated the performance of MGIT culture in routine condition after two years of its implementation in a public laboratories network.This is a retrospective study, which analyzed the data on the liquid culture performed in ten regional laboratories of the Institute Adolfo Lutz, from January to March 2010. The data included clinical samples submitted to microscopy, automated or manual MGIT culture and presumptive M. tuberculosis complex (MTBC) identification by analyzing the cord formation. Culture was positive in 1,159 samples. Of these, 113 (9.7%) contaminated, and 1,046 were analyzed, of which 850 (81.3%) were identified as MTBC, 116 (11.1%) as non-tuberculous mycobacteria and 6 (0.6%) as Nocardia sp. Contamination rate was 2.2% and the contribution of culture to the TB diagnosis was 29.9%. The detection mean time was 14.7 days (SD+/-11.7 days). The accuracy of the presumptive identification of MTBC was 91.3%. MGIT liquid culture demonstrated to be an excellent alternative for diagnosing TB and mycobacterioses, because of the rapidity of diagnosis, thus allowing an immediate and effective treatment.


Assuntos
Cultura de Vírus , Fatores Corda , Mycobacterium tuberculosis , Tuberculose/diagnóstico , Técnicas de Laboratório Clínico/métodos
13.
J Microbiol Methods ; 127: 24-27, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27164021

RESUMO

Attempts were made to enhance the sensitivity of immuno-PCR assay based on the detection of cocktail of mycobacterial antigen 85B (Rv1886c), ESAT-6 (Rv3875) and cord factor (trehalose 6,6'-dimycolate) in pulmonary and extrapulmonary TB patients. Detection of Ag85B was found to be superior to the detection of cocktail in TB patients.


Assuntos
Antígenos de Bactérias/análise , Fatores Corda/análise , Reação em Cadeia da Polimerase/métodos , Tuberculose/diagnóstico , Antígenos de Bactérias/imunologia , Fatores Corda/imunologia , Imunoensaio/métodos , Tuberculose/microbiologia , Tuberculose Pulmonar/diagnóstico , Tuberculose Pulmonar/microbiologia
14.
J Microbiol Methods ; 120: 56-64, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26625715

RESUMO

A novel indirect immuno-polymerase chain reaction (I-PCR) assay was developed for the detection of circulating anti-Ag85B (antigen 85B, Rv1886c), anti-ESAT-6 (early secretory antigenic target-6, Rv3875) and anti-cord factor (trehalose 6,6'-dimycolate) antibodies from the sera samples of pulmonary tuberculosis (PTB) and extrapulmonary tuberculosis (EPTB) patients and the results were compared with an analogous enzyme-linked immunosorbent assay (ELISA). We covalently attached the amino-modified reporter DNA to the dithiothreitol (DTT)-reduced anti-human IgG antibody through a chemical linker succinimidyl 4-[N-maleimidomethyl]-cyclohexane-1-carboxylate (SMCC). The detection of cocktail of anti-Ag85B, anti-ESAT-6 and anti-cord factor antibodies was found to be superior to the detection of individual antibodies. The sensitivities of 89.5% and 77.5% with I-PCR and 70.8% and 65% with ELISA were observed in smear-positive and smear-negative PTB cases, respectively with high specificity (90.9%). On the other hand, a sensitivity of 77.5% with I-PCR and 65% with ELISA was observed in EBTB cases. The detection of cocktail of antibodies by I-PCR is likely to improve the utility of existing algorithms for TB diagnosis.


Assuntos
Aciltransferases/imunologia , Antígenos de Bactérias/imunologia , Proteínas de Bactérias/imunologia , Fatores Corda/imunologia , Mycobacterium tuberculosis/imunologia , Reação em Cadeia da Polimerase/métodos , Testes Sorológicos/métodos , Tuberculose/diagnóstico , Aciltransferases/sangue , Adolescente , Adulto , Anticorpos Antibacterianos/sangue , Anticorpos Antibacterianos/imunologia , Especificidade de Anticorpos , Antígenos de Bactérias/sangue , Proteínas de Bactérias/sangue , Fatores Corda/sangue , Ditiotreitol/química , Ditiotreitol/imunologia , Ensaio de Imunoadsorção Enzimática/métodos , Humanos , Imunoensaio/métodos , Imunoglobulina G/sangue , Imunoglobulina G/química , Maleimidas , Pessoa de Meia-Idade , Tuberculose/sangue , Tuberculose/imunologia , Tuberculose Pulmonar/sangue , Tuberculose Pulmonar/diagnóstico , Tuberculose Pulmonar/imunologia , Adulto Jovem
15.
FEMS Microbiol Lett ; 362(23): fnv185, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26449555

RESUMO

For successful colonization of a host, pathogenic bacteria are equipped with a plethora of proteins and other components, often designated as virulence factors. However, many of these factors are involved in general adaptation to ecological niches rather than being specific for interaction of a bacterial pathogen with a distinct host. Therefore, a designation of these components as niche factors was proposed. While originally developed for different species colonizing the gastro-intestinal tract, in this communication the concept of niche factors is discussed in respect to a single genus, i.e. Corynebacterium species.


Assuntos
Corynebacterium/patogenicidade , Fatores de Virulência/metabolismo , Animais , Fatores Corda/metabolismo , Corynebacterium/classificação , Corynebacterium/genética , Corynebacterium/fisiologia , Toxina Diftérica/genética , Toxina Diftérica/metabolismo , Humanos , Ácidos Micólicos/metabolismo , Fosfolipases/metabolismo , Fatores de Virulência/genética
16.
Chem Phys Lipids ; 189: 28-38, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26022243

RESUMO

The synthesis of an α'-mycolic acid of Mycobacterium smegmatis and other mycobacteria, containing a cis,cis-diene, and of the trehalose mono- and di-mycolates of this, and of a related α'-mycolic acid containing one cis-alkene, is reported.


Assuntos
Alcenos/química , Ácidos Micólicos/química , Trealose/química , Ésteres , Isomerismo , Espectroscopia de Ressonância Magnética , Mycobacterium/química , Mycobacterium/metabolismo , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Trealose/síntese química
17.
Pan Afr Med J ; 18: 141, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25419279

RESUMO

INTRODUCTION: World Health Organization had estimated 9.4 million tuberculosis cases on 2009, with 1.7 million of deaths as consequence of treatment and diagnosis failures. Improving diagnostic methods for the rapid and timely detection of tuberculosis patients is critical to control the disease. The aim of this study was evaluating the accuracy of the cord factor detection on the solid medium Middlebrook 7H11 thin layer agar compared to the Lowenstein Jensen medium for the rapid tuberculosis diagnosis. METHODS: Patients with suspected tuberculosis were enrolled and their sputum samples were processed for direct smear and culture on Lowenstein Jensen and BACTEC MGIT 960, from which positive tubes were subcultured on Middlebrook 7H11 thin layer agar. Statistical analysis was performed comparing culture results from Lowenstein Jensen and the thin layer agar, and their corresponding average times for detecting Mycobacterium tuberculosis. The performance of cord factor detection was evaluated determining its sensitivity, specificity, positive and negative predictive value. RESULTS: 111 out of 260 patients were positive for M. tuberculosis by Lowenstein Jensen medium with an average time ± standard deviation for its detection of 22.3 ± 8.5 days. 115 patients were positive by the MGIT system identifying the cord factor by the Middlebrook 7H11 thin layer agar which average time ± standard deviation was 5.5 ± 2.6 days. CONCLUSION: The cord factor detection by Middlebrook 7H11 thin layer agar allows early and accurate tuberculosis diagnosis during an average time of 5 days, making this rapid diagnosis particularly important in patients with negative sputum smear.


Assuntos
Tuberculose Pulmonar/diagnóstico , Técnicas Bacteriológicas/métodos , Fatores Corda/análise , Reações Falso-Negativas , Humanos , Mycobacterium tuberculosis/isolamento & purificação , Mycobacterium tuberculosis/ultraestrutura , Valor Preditivo dos Testes , Sensibilidade e Especificidade , Escarro/microbiologia
18.
Front Immunol ; 5: 288, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25002863

RESUMO

Macrophage C-type lectin (MCL) and macrophage inducible C-type lectin (Mincle) comprise part of an extensive repertoire of pattern recognition receptors with the ability to sense damage-associated and pathogen-associated molecular patterns. In this review, we cover the discovery and molecular characterization of these C-type lectin receptors, and highlight recent advances in the understanding of their roles in orchestrating the response of the immune system to bacterial and fungal infection, and damaged self. We also discuss the identification and structure-activity relationships of activating ligands, particularly trehalose dimycolate and related mycobacterial glycolipids, which have significant potential in the development of TH1/TH17 vaccination strategies.

19.
J Biol Chem ; 288(40): 28457-65, 2013 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-23960080

RESUMO

Binding of the macrophage lectin mincle to trehalose dimycolate, a key glycolipid virulence factor on the surface of Mycobacterium tuberculosis and Mycobacterium bovis, initiates responses that can lead both to toxicity and to protection of these pathogens from destruction. Crystallographic structural analysis, site-directed mutagenesis, and binding studies with glycolipid mimics have been used to define an extended binding site in the C-type carbohydrate recognition domain (CRD) of bovine mincle that encompasses both the headgroup and a portion of the attached acyl chains. One glucose residue of the trehalose Glcα1-1Glcα headgroup is liganded to a Ca(2+) in a manner common to many C-type CRDs, whereas the second glucose residue is accommodated in a novel secondary binding site. The additional contacts in the secondary site lead to a 36-fold higher affinity for trehalose compared with glucose. An adjacent hydrophobic groove, not seen in other C-type CRDs, provides a docking site for one of the acyl chains attached to the trehalose, which can be targeted with small molecule analogs of trehalose dimycolate that bind with 52-fold higher affinity than trehalose. The data demonstrate how mincle bridges between the surfaces of the macrophage and the mycobacterium and suggest the possibility of disrupting this interaction. In addition, the results may provide a basis for design of adjuvants that mimic the ability of mycobacteria to stimulate a response to immunization that can be employed in vaccine development.


Assuntos
Glicolipídeos/metabolismo , Lectinas Tipo C/metabolismo , Mycobacterium/metabolismo , Receptores Imunológicos/metabolismo , Sequência de Aminoácidos , Aminoácidos/metabolismo , Animais , Sítios de Ligação , Bovinos , Cristalografia por Raios X , Glucose/metabolismo , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Lectinas Tipo C/química , Ligantes , Modelos Moleculares , Dados de Sequência Molecular , Mutagênese/genética , Ligação Proteica , Estrutura Terciária de Proteína , Receptores Imunológicos/química , Trealose/química , Trealose/metabolismo
20.
FASEB J ; 27(8): 3067-77, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23603838

RESUMO

Bacteriophages, the viruses of eubacteria, have developed unique mechanisms to interact with their host bacteria. They have been viewed as potential antibacterial therapeutics. Mycobacteriophage-derived compounds may interact with Mycobacterium tuberculosis (MTB) and/or its components, such as the cord factor, trehalose-6,6'-dimycolate (TDM), which is the most abundant glycolipid produced on the surface of MTB. TDM emulsion injected intravenously into mice induces lung immunopathology that mimics many aspects of MTB infection. Thus, TDM is an important target for anti-MTB agent development. On the basis of genomics information of mycobacteriophages, 200 peptides were synthesized. Their effects on MTB, their interactions with TDM, and anti-inflammatory activities were tested. One of them (PK34) showed MTB-killing activity with a minimal inhibitory concentration of 50 µg/ml and TDM-binding ability. In a mouse model, PK34 showed comparable ability to clear MTB as rifampin did in vivo. It also exerted strong activity to inhibit MTB or TDM-induced inflammation in vivo. PK34 significantly inhibited inflammatory cytokines secretions by inactivating MAPK and PKB signals while it maintained certain proinflammatory cytokine production. It is possible to prospect for TDM-binding and/or anti-MTB peptides by mining the mycobacteriophages genome. In addition to its direct MTB-killing ability, PK34 might be a useful adjunct in the treatment of granulomatous inflammation occurring during mycobacterial infection or a template for developing antituberculosis (TB) agents because of its immunoregulative effects. As a TDM-binding peptide, PK34 may be a promising tool to study TDM's interactions with corresponding receptors and signal pathways.


Assuntos
Antibacterianos/metabolismo , Anti-Inflamatórios/metabolismo , Fatores Corda/metabolismo , Micobacteriófagos/metabolismo , Peptídeos/metabolismo , Adjuvantes Imunológicos/farmacologia , Animais , Antibacterianos/farmacologia , Anti-Inflamatórios/farmacologia , Western Blotting , Linhagem Celular , Fatores Corda/farmacologia , Citocinas/metabolismo , Feminino , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Pulmão/patologia , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Testes de Sensibilidade Microbiana , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Micobacteriófagos/genética , Mycobacterium tuberculosis/efeitos dos fármacos , Peptídeos/genética , Peptídeos/farmacologia , Ligação Proteica , Proteínas Proto-Oncogênicas c-akt , Rifampina/farmacologia , Tuberculose/tratamento farmacológico , Tuberculose/microbiologia
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