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1.
PLoS One ; 16(3): e0249184, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33770127

RESUMO

Mycobacterium leprae (M. leprae) is the etiological agent of leprosy, and the skin lesions of lepromatous leprosy are filled with numerous foamy or xanthomatous histiocytes that are parasitized by M. leprae. Lipids are an important nutrient for the intracellular survival of M. leprae. In this study, we attempted to determine the intracellular lipid composition and underlying mechanisms for changes in host cell lipid metabolism induced by M. leprae infection. Using high-performance thin-layer chromatography (HPTLC), we demonstrated specific induction of triacylglycerol (TAG) production in human macrophage THP-1 cells following M. leprae infection. We then used [14C] stearic acid tracing to show incorporation of this newly synthesized host cell TAG into M. leprae. In parallel with TAG accumulation, expression of host glycerol-3-phosphate acyltransferase 3 (GPAT3), a key enzyme in de novo TAG synthesis, was significantly increased in M. leprae-infected cells. CRISPR/Cas9 genome editing of GPAT3 in THP-1 cells (GPAT3 KO) dramatically reduced accumulation of TAG following M. leprae infection, intracellular mycobacterial load, and bacteria viability. These results together suggest that M. leprae induces host GPAT3 expression to facilitate TAG accumulation within macrophages to maintain a suitable environment that is crucial for intracellular survival of these bacilli.


Assuntos
Mycobacterium leprae/genética , Mycobacterium leprae/metabolismo , Fator de Transcrição STAT3/genética , Triglicerídeos/biossíntese , Linhagem Celular , Expressão Gênica , Humanos , Monócitos/citologia
3.
PLoS Negl Trop Dis ; 14(7): e0007871, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32628669

RESUMO

Leprosy, caused by Mycobacterium leprae, has plagued humanity for thousands of years and continues to cause morbidity, disability and stigmatization in two to three million people today. Although effective treatment is available, the disease incidence has remained approximately constant for decades so new approaches, such as vaccine or new drugs, are urgently needed for control. Research is however hampered by the pathogen's obligate intracellular lifestyle and the fact that it has never been grown in vitro. Consequently, despite the availability of its complete genome sequence, fundamental questions regarding the biology of the pathogen, such as its metabolism, remain largely unexplored. In order to explore the metabolism of the leprosy bacillus with a long-term aim of developing a medium to grow the pathogen in vitro, we reconstructed an in silico genome scale metabolic model of the bacillus, GSMN-ML. The model was used to explore the growth and biomass production capabilities of the pathogen with a range of nutrient sources, such as amino acids, glucose, glycerol and metabolic intermediates. We also used the model to analyze RNA-seq data from M. leprae grown in mouse foot pads, and performed Differential Producibility Analysis to identify metabolic pathways that appear to be active during intracellular growth of the pathogen, which included pathways for central carbon metabolism, co-factor, lipids, amino acids, nucleotides and cell wall synthesis. The GSMN-ML model is thereby a useful in silico tool that can be used to explore the metabolism of the leprosy bacillus, analyze functional genomic experimental data, generate predictions of nutrients required for growth of the bacillus in vitro and identify novel drug targets.


Assuntos
Genoma Bacteriano , Hanseníase/microbiologia , Redes e Vias Metabólicas , Mycobacterium leprae/genética , Mycobacterium leprae/metabolismo , Animais , Humanos , Camundongos , Camundongos Nus , Mycobacterium leprae/crescimento & desenvolvimento
4.
Int J Biol Macromol ; 152: 250-260, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32084461

RESUMO

Gold nanoparticles (AuNPs) and silver nanoparticles (AgNPs) have several biomedical applications. However, the effective usage of these two nanoparticles is impeded due to limited understanding of their interaction with proteins including small heat shock proteins (sHSPs). Specifically, no evidences of interaction of these two nanoparticles with HSP18 (an antigenic protein) which is an important factor for the growth and survival of M. leprae (the causative organism of leprosy) are available in the literature. Here, we report for the first time evidences of "HSP18-AuNPs/AgNPs interaction" and its impact on the structure and chaperone function of HSP18. Interaction of citrate-capped AuNPs/AgNPs (~20 nm diameter) to HSP18 alters the secondary and tertiary structure of HSP18 in a distinctly opposite manner; while "HSP18-AuNPs interaction" leads to oligomeric association, "HSP18-AgNPs interaction" results in oligomeric dissociation of the protein. Surface hydrophobicity, thermal stability, chaperone function of HSP18 and survival of thermally stressed E. coli harbouring HSP18 are enhanced upon AuNPs interaction, while all of them are reduced upon interaction with AgNPs. Altogether, our study reveals that HSP18 is an important drug target in leprosy and its chaperone function may possibly plays a vital role in the growth and survival of M. leprae pathogen in infected hosts.


Assuntos
Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Ouro/química , Proteínas de Choque Térmico/química , Proteínas de Choque Térmico/metabolismo , Nanopartículas Metálicas/química , Chaperonas Moleculares/metabolismo , Mycobacterium leprae/metabolismo , Prata/química , Escherichia coli/metabolismo , Resposta ao Choque Térmico/fisiologia , Hanseníase/metabolismo , Chaperonas Moleculares/química , Mycobacterium leprae/química
5.
Int J Biol Macromol ; 146: 648-660, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31883890

RESUMO

Mycobacterium leprae, causative organism of leprosy, is known to counter redox stress generated by reactive oxygen species (ROS) during its survival inside host macrophages. But, the involvement of any antigenic protein(s) for countering such redox stress is still unknown. Interestingly, M. leprae HSP18, an important antigenic protein that helps in the growth and survival of M. leprae pathogen inside host macrophages, is induced under redox stress. Moreover, HSP18 also interacts with Cu2+. Copper (II) can induce redox stress via Fenton reaction. But, whether HSP18 suppresses Cu2+ mediated ROS generation, is still far from clear. Also, the effect of redox stress on its structure and function is not known. In this study, we show that HSP18 efficiently suppresses Cu2+ mediated generation of ROS and also prevents the redox mediated aggregation of a client protein (γD-crystallin). Upon exposure to substantial redox stress, irreversible perturbation in the secondary and tertiary structure of HSP18 and the tryptophan and tyrosine oxidation are evidenced. Interestingly, HSP18 retains a considerable amount of functionality even after being exposed to substantial redox stress. Perhaps, the redox scavenging ability as well as the chaperone function of HSP18 may possibly help M. leprae pathogen to counter redox stress inside host macrophages.


Assuntos
Proteínas de Bactérias/metabolismo , Cobre/metabolismo , Proteínas de Choque Térmico/metabolismo , Mycobacterium leprae/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Ácido Ascórbico/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/farmacologia , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/farmacologia , Peróxido de Hidrogênio/metabolismo , Radical Hidroxila/metabolismo , Macrófagos/microbiologia , Chaperonas Moleculares/metabolismo , Mycobacterium leprae/genética , Oxirredução/efeitos dos fármacos , Proteínas Recombinantes , Tirosina/metabolismo
6.
Dis Mon ; 66(7): 100918, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31813526

RESUMO

The present review summarizes the current updates on dental perspectives on leprosy and the affording factors that are responsible for the prevalence of caries and periodontal diseases in leprosy. It also highlights immunopathological phenomena and reactional episodes of leprosy that occur due to daedal interactions between the perio-odontopathic bacteria and M. leprae. In addition, a brief introduction, historiography, classification and clinicopathological aspects are also been covered.


Assuntos
Cárie Dentária/epidemiologia , Hanseníase/patologia , Mycobacterium leprae/isolamento & purificação , Periodonto/microbiologia , Carga Bacteriana/tendências , História do Século XIX , Humanos , Imunidade Celular/fisiologia , Hanseníase/classificação , Hanseníase/história , Hanseníase/microbiologia , Mycobacterium leprae/metabolismo , Doenças Periodontais/complicações , Periodonto/patologia , Prevalência
7.
Sci Rep ; 9(1): 10815, 2019 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-31346236

RESUMO

Leprosy, an important infectious disease in humans caused by Mycobacterium leprae (Mle), remains endemic in many countries. Notably, the pathogen cannot be cultured in vitro, except in mouse footpads in vivo. The molecular basis of these characteristics and the mechanisms remain unknown. Consequently, analysis of Mle growth and survival is urgently needed to develop novel therapies against leprosy, including rapid, simple, and specific methods to detect infection. Here, we demonstrated the functional role and contribution of Mle-DNA gyrase, which regulates DNA topology, DNA replication, and chromosome segregation to promote bacterial growth and survival, in Mle growth and survival in vitro and in vivo. The optimum temperature for Mle-DNA gyrase activity was 30 °C. When the DNA gyrB-gyrA genes in Mycobacterium smegmatis were replaced with the Mle gyrase genes by allelic exchange, the recombinants could not grow at 37 °C. Moreover, using radiorespirometry analysis for viability of Mle bacilli, we found that Mle growth was more vigorous at 25-30 °C than at 37 °C, but was inhibited above 40 °C. These results propose that DNA gyrase is a crucial factor for Mle growth and survival and its sensitivity to temperature may be exploited in heat-based treatment of leprosy.


Assuntos
Técnicas de Cultura de Células , DNA Girase/metabolismo , Replicação do DNA/fisiologia , DNA Bacteriano , Mycobacterium leprae/crescimento & desenvolvimento , Hanseníase/microbiologia , Mycobacterium leprae/metabolismo
8.
Emerg Microbes Infect ; 8(1): 109-118, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30866765

RESUMO

Of the more than 190 distinct species of Mycobacterium genus, many are economically and clinically important pathogens of humans or animals. Among those mycobacteria that infect humans, three species namely Mycobacterium tuberculosis (causative agent of tuberculosis), Mycobacterium leprae (causative agent of leprosy) and Mycobacterium abscessus (causative agent of chronic pulmonary infections) pose concern to global public health. Although antibiotics have been successfully developed to combat each of these, the emergence of drug-resistant strains is an increasing challenge for treatment and drug discovery. Here we describe the impact of the rapid expansion of genome sequencing and genome/pathway annotations that have greatly improved the progress of structure-guided drug discovery. We focus on the applications of comparative genomics, metabolomics, evolutionary bioinformatics and structural proteomics to identify potential drug targets. The opportunities and challenges for the design of drugs for M. tuberculosis, M. leprae and M. abscessus to combat resistance are discussed.


Assuntos
Proteínas de Bactérias/química , Biologia Computacional/métodos , Mycobacterium/genética , Análise de Sequência de DNA/métodos , Animais , Proteínas de Bactérias/metabolismo , Descoberta de Drogas , Farmacorresistência Bacteriana , Genoma Bacteriano , Humanos , Anotação de Sequência Molecular , Mycobacterium/metabolismo , Mycobacterium abscessus/genética , Mycobacterium abscessus/metabolismo , Mycobacterium leprae/genética , Mycobacterium leprae/metabolismo , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/metabolismo , Conformação Proteica , Proteômica
9.
Microb Pathog ; 124: 316-321, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30172902

RESUMO

Mycobacterium leprae is an unculturable obligate pathogen and causative agent for debilitating human disease leprosy. Due to reductive genome evolution M leprae genome harbours large number of pseudogenes and small number of genes (∼1600 genes and ∼1300 pseudogenes). How M leprae remained a successful human parasite with small set of genes remains poorly understood and provided us the impetus to investigate the intergenic regions of M leprae genome for the presence of possible open reading frames (ORFs). In this work, we have manually scanned all the intergenic regions of M leprae genome and identified 106 potential ORFs. Among these, 12 are large ORFs: encoding hypothetical proteins (HP) of more than 100 amino acids. We have also found 67 ORFs encoding 50-100 amino acids proteins and another 27 ORFs for 30-50 amino acids peptides. We have validated the presence of transcripts for large HPs by quantitative reverse transcriptase PCR (qRT-PCR). Our results suggest that some of the M leprae large HPs are indeed expressed at low level in leprosy patients. The present results will shed light on the intergenic ORFs of M leprae and further our understanding of the pathogenesis of leprosy.


Assuntos
Proteínas de Bactérias/genética , DNA Intergênico/genética , Genoma Bacteriano , Hanseníase/microbiologia , Mycobacterium leprae/genética , Fases de Leitura Aberta , Humanos , Mycobacterium leprae/metabolismo , Pseudogenes , Reação em Cadeia da Polimerase Via Transcriptase Reversa
10.
J Inorg Biochem ; 188: 62-75, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30121399

RESUMO

Mycobacterium leprae uptakes various bivalent metal ions via different transporters in host species. Uptake of Cu2+ and Zn2+ are essential for generation of superoxide dismutases and catalases, which provide defense against reactive oxygen species mediated death of this pathogen in macrophages. Furthermore, it has also been noticed that levels of different bivalent metal ions (Ca2+, Mg2+, Cu2+ and Zn2+) in blood serum are altered in leprotic patients. Mycobacterium leprae HSP18 is an immunodominant antigen which helps in growth and survival of Mycobacterium leprae in host species. A possible link can exist between HSP18 and aberration of bivalent metal ion homeostasis. Therefore, we investigated the interaction of these four bivalent metal ions with HSP18 and found that the protein only interacts with Zn2+ and Cu2+. Such association process is reversible and moderately high affinity in nature with unit binding stoichiometry. Theoretical studies revealed that the most probable site for Zn2+-binding lies in the N-terminal domain; While, the same for Cu2+-binding lies in the "α-crystallin domain" of HSP18. Binding of Zn2+/Cu2+ to HSP18 brings about subtle changes in the secondary and tertiary structure of HSP18 but are distinctly opposite in nature. While Zn2+ causes oligomeric association, Cu2+ leads to oligomeric dissociation of HSP18. Structural stability, surface hydrophobicity and chaperone activity of HSP18 are enhanced on Zn2+ binding, while all of them are reduced upon Cu2+ binding. Altogether, metal ions binding to HSP18 regulate its function which may have far reaching effect on the survival and pathogenicity of Mycobacterium leprae in host species.


Assuntos
Proteínas de Bactérias/química , Cobre/química , Proteínas de Choque Térmico/química , Mycobacterium leprae/química , Zinco/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Cátions Bivalentes/química , Cátions Bivalentes/metabolismo , Cobre/metabolismo , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Humanos , Mycobacterium leprae/genética , Mycobacterium leprae/metabolismo , Ligação Proteica , Zinco/metabolismo
11.
Int J Biol Macromol ; 119: 604-616, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30055280

RESUMO

Ultraviolet radiation, an effective sterilizing source, rapidly kills the causative organism (Mycobacterium leprae) of leprosy. But, the reasons behind this quick death are not clearly understood. Also, the impact of UV radiation on the antigen(s) which is/are responsible for the survival of this pathogen is still unknown. Many reports have revealed that M. leprae secrets a major immunodominant antigen, namely HSP18, whose chaperone function plays an important role in the growth and survival of this pathogen under various environmental insults. However, the effect of UV radiation on its structure and chaperone function is still unclear. Therefore, we have taken a thorough attempt to understand these two aspects of HSP18 under different UV radiations (UVA/UVB/UVC; doses: 1-50 J/cm2). Our study revealed that its chaperone function is decreased significantly with increasing doses of various UV radiations. These different UV irradiations perturb only its tertiary structure and induce tryptophan and tyrosine photo-oxidation to N-formyl kynurenine, kynurenine and dityrosine. Such photo-oxidation promotes the subunit cross-linking within a HSP18 oligomer, lowers the surface hydrophobicity and thermostability of the protein. All these factors together damage/reduce the chaperone function of HSP18 which may be an important factor behind the rapid death of M. leprae under UV exposure.


Assuntos
Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Proteínas de Choque Térmico/química , Proteínas de Choque Térmico/metabolismo , Mycobacterium leprae/metabolismo , Mycobacterium leprae/efeitos da radiação , Raios Ultravioleta , Sequência de Aminoácidos , Relação Dose-Resposta à Radiação , Viabilidade Microbiana/efeitos da radiação , Mycobacterium leprae/fisiologia , Relação Estrutura-Atividade
12.
PLoS Pathog ; 14(7): e1007151, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29979790

RESUMO

Mycobacterium leprae, an obligate intracellular bacillus, infects Schwann cells (SCs), leading to peripheral nerve damage, the most severe leprosy symptom. In the present study, we revisited the involvement of phenolic glycolipid I (PGL I), an abundant, private, surface M. leprae molecule, in M. leprae-SC interaction by using a recombinant strain of M. bovis BCG engineered to express this glycolipid. We demonstrate that PGL I is essential for bacterial adhesion and SC internalization. We also show that live mycobacterium-producing PGL I induces the expression of the endocytic mannose receptor (MR/CD206) in infected cells in a peroxisome proliferator-activated receptor gamma (PPARγ)-dependent manner. Of note, blocking mannose recognition decreased bacterial entry and survival, pointing to a role for this alternative recognition pathway in bacterial pathogenesis in the nerve. Moreover, an active crosstalk between CD206 and the nuclear receptor PPARγ was detected that led to the induction of lipid droplets (LDs) formation and prostaglandin E2 (PGE2), previously described as fundamental players in bacterial pathogenesis. Finally, this pathway was shown to induce IL-8 secretion. Altogether, our study provides evidence that the entry of live M. leprae through PGL I recognition modulates the SC phenotype, favoring intracellular bacterial persistence with the concomitant secretion of inflammatory mediators that may ultimately be involved in neuroinflammation.


Assuntos
Antígenos de Bactérias/metabolismo , Glicolipídeos/metabolismo , Lectinas Tipo C/metabolismo , Hanseníase/metabolismo , Lectinas de Ligação a Manose/metabolismo , PPAR gama/metabolismo , Receptores de Superfície Celular/metabolismo , Células de Schwann/virologia , Humanos , Mycobacterium leprae/metabolismo , Receptor Cross-Talk/fisiologia
14.
Gene ; 643: 26-34, 2018 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-29208413

RESUMO

Mycobacterium leprae has a reduced genome size due to the reductive evolution over a long period of time. Lipid metabolism plays an important role in the life cycle and pathogenesis of this bacterium. In comparison to 26 lip genes (Lip A-Z) of M. tuberculosis, M. leprae retained only three orthologs indicating their importance in its life cycle. ML0314c (LipU) is one of them. It is conserved throughout the mycobacterium species. Bioinformatics analysis showed the presence of an α/ß hydrolase fold and 'GXSXG' characteristic of the esterases/lipases. The gene was expressed in E. coli and purified to homogeneity. It showed preference towards short chain esters with pNP-acetate as the preferred substrate. The enzyme showed optimal activity at 45°C and pH8.0. ML0314c protein was stable between temperatures ranging from 20 to 60°C and pH5.0-8.0, i.e., relatively acidic and neutral conditions. The active site residues predicted bioinformatically were confirmed to be Ser168, Glu267, and His297 by site directed mutagenesis. E-serine, DEPC and Tetrahydrolipstatin (THL) completely inhibited the activity of ML0314c. The protein was localized in cell wall and extracellular medium. Several antigenic epitopes were predicted in ML0314c. Protein elicited strong humoral immune response in leprosy patients, whereas, a reduced immune response was observed in the relapsed cases. No humoral response was observed in treatment completed patients. Overexpression of ml0314c in the surrogate host M. smegmatis showed marked difference in the colony morphology and growth rate. In conclusion, ML0314c is a secretary carboxyl esterase that could modulate the immune response in leprosy patients.


Assuntos
Lipólise/genética , Mycobacterium leprae/genética , Mycobacterium leprae/metabolismo , Sequência de Aminoácidos/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Hidrolases de Éster Carboxílico/metabolismo , Domínio Catalítico/genética , Clonagem Molecular/métodos , Escherichia coli/genética , Humanos , Concentração de Íons de Hidrogênio , Hanseníase/metabolismo , Hanseníase/microbiologia , Lipase/genética , Metabolismo dos Lipídeos/genética , Lipídeos , Mutagênese Sítio-Dirigida/métodos , Mycobacterium tuberculosis/genética , Especificidade por Substrato/genética , Fatores de Virulência
15.
Microbes Infect ; 19(11): 505-514, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28684130

RESUMO

Our previous study has demonstrated that IL-10 may modulate both indoleamine 2,3-dioxygenase (IDO) and CD163 expression in lepromatous leprosy (LL) cells, favoring Mycobacterium leprae persistence through induction of regulatory pathways and iron storage. Here, we observed that in LL lesion cells there is an increase in the expression of proteins involved in iron metabolism such as hemoglobin (Hb), haptoglobin, heme oxygenase 1 and transferrin receptor 1 (TfR1) when compared to tuberculoid leprosy (BT) cells. We also found increased iron deposits and diminished expression of the iron exporter ferroportin 1 in LL lesion cells. Hemin, but not FeSO4 stimulation, was able to enhance M. leprae viability by a mechanism that involves IDO. Analysis of cell phenotype in lesions demonstrated a predominance of M2 markers in LL when compared with BT lesion cells. A positive correlation between CD163 and PPARG with the bacillary index (BI) was observed. In contrast, TNF, STAT1 and CSF2 presented a negative correlation with the BI. In summary, this study demonstrates that iron may regulate IDO expression by a mechanism that involves IL-10, which may contribute for the predominance of M2-like phenotype in LL lesions that favors the phagocytosis and maintenance of M. leprae in host cells.


Assuntos
Indolamina-Pirrol 2,3,-Dioxigenase/fisiologia , Ferro/fisiologia , Mycobacterium leprae/fisiologia , Adulto , Feminino , Humanos , Immunoblotting , Técnicas Imunoenzimáticas , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Ferro/metabolismo , Hanseníase Virchowiana/metabolismo , Hanseníase Virchowiana/microbiologia , Masculino , Pessoa de Meia-Idade , Mycobacterium leprae/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa
16.
Biosci Biotechnol Biochem ; 81(7): 1343-1347, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28417702

RESUMO

Quinolones are important antimicrobials for treatment of leprosy, a chronic infectious disease caused by Mycobacterium leprae. Although it is well known that mutations in DNA gyrase are responsible for quinolone resistance, the effect of those mutations on the enzymatic activity is yet to be studied in depth. Hence, we conducted in vitro assays to observe supercoiling reactions of wild type and mutated M. leprae DNA gyrases. DNA gyrase with amino acid substitution Ala91Val possessed the highest activity among the mutants. DNA gyrase with Gly89Cys showed the lowest level of activity despite being found in clinical strains, but it supercoiled DNA like the wild type does if applied at a sufficient concentration. In addition, patterns of time-dependent conversion from relaxed circular DNA into supercoiled DNA by DNA gyrases with clinically unreported Asp95Gly and Asp95Asn were observed to be distinct from those by the other DNA gyrases.


Assuntos
Substituição de Aminoácidos , Antibacterianos/farmacologia , DNA Girase/química , Mutação , Mycobacterium leprae/efeitos dos fármacos , Quinolonas/farmacologia , Clonagem Molecular , DNA Girase/genética , DNA Girase/metabolismo , DNA Bacteriano/química , DNA Bacteriano/metabolismo , DNA Circular/química , DNA Circular/metabolismo , DNA Super-Helicoidal/química , DNA Super-Helicoidal/metabolismo , Farmacorresistência Bacteriana , Ensaios Enzimáticos , Escherichia coli/genética , Escherichia coli/metabolismo , Expressão Gênica , Cinética , Mycobacterium leprae/genética , Mycobacterium leprae/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Relação Estrutura-Atividade
17.
Future Microbiol ; 12: 315-335, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28287297

RESUMO

Mycobacterium leprae must adopt a metabolic strategy and undergo various metabolic alterations upon infection to survive inside the human body for years in a dormant state. A change in lipid homeostasis upon infection is highly pronounced in Mycobacterium leprae. Lipids play an essential role in the survival and pathogenesis of mycobacteria. Lipids are present in several forms and serve multiple roles from being a source of nutrition, providing rigidity, evading the host immune response to serving as virulence factors, etc. The synthesis and degradation of lipids is a highly regulated process and is the key to future drug designing and diagnosis for mycobacteria. In the current review, an account of the distinct roles served by lipids, the mechanism of their synthesis and degradation has been elucidated.


Assuntos
Hanseníase/microbiologia , Metabolismo dos Lipídeos , Mycobacterium leprae/metabolismo , Animais , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Humanos , Hanseníase/metabolismo , Mycobacterium leprae/genética , Mycobacterium leprae/crescimento & desenvolvimento , Fatores de Virulência/genética , Fatores de Virulência/metabolismo
18.
Extremophiles ; 21(1): 41-49, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27704298

RESUMO

Inteins are the protein equivalent of introns. They are seamlessly removed during post-translational maturation of their host protein (extein). Inteins from extremophiles played a key role in understanding intein-mediated protein splicing. There are currently three classes of inteins defined by catalytic mechanism and sequence signatures. This study demonstrates splicing of three class 3 mini-inteins: Burkholderia vietnamiensis G4 Bvi IcmO intein, Mycobacterium smegmatis MC2 155 Msm DnaB-1 intein and Mycobacterium leprae strain TN Mle DnaB intein. B. vietnamiensis has a broad ecological range and remediates trichloroethene. M. smegmatis is a biofilm forming soil bacteria. Although other intein classes have only a single branched intermediate at the C-terminal splice junction, the class 3 intein reaction pathway includes two branched intermediates. The class 3 specific branched intermediate is formed by an internal cysteine, while the C-terminal branch intermediate is at a serine or threonine in all class 3 inteins except the Bvi IcmO intein, where it is a cysteine. This latter cysteine was unable to compensate for mutation of the class 3-specific internal catalytic cysteine despite the Bvi IcmO intein having an N-terminal splice junction naturally tuned for a cysteine nucleophile, demonstrating the mandatory order of branch intermediates in class 3 inteins.


Assuntos
Proteínas de Bactérias/metabolismo , Burkholderia/metabolismo , Inteínas , Mycobacterium leprae/metabolismo , Processamento de Proteína Pós-Traducional , Proteínas de Bactérias/química , Burkholderia/genética , Mycobacterium leprae/genética
19.
Am J Phys Anthropol ; 162(1): 143-156, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27704524

RESUMO

It is possible that during long lasting chronic infections such as tuberculosis (TB) and leprosy individuals who generate a stronger immune response will produce a chronic shift in the systemic levels of inflammatory proteins. Consequently, the systemic immunological shift could affect inflammatory responses against other persistent pathogens such as Porphyromonas gingivalis associated with periodontal disease (PD). OBJECTIVE: To determine if in vitro exposure to Mycobacterium tuberculosis or M. leprae lysates impacts subsequent immune responses to P. gingivalis; and to propose a new dialogue between experimental immunology and paleopathology. MATERIAL AND METHODS: We sequentially (2 days protocol) exposed peripheral blood mononuclear cells (PBMCs) from healthy donors to bacterial lysates either from M. tuberculosis, or M. leprae, or P. gingivalis. After collecting all supernatants, we measured the expression of immune proteins TNFα and IFNγ using an enzyme-linked immunosorbent assay. RESULTS: Early exposure (day 1) of PBMCs to M. leprae or M. tuberculosis lysates induces an inflammatory shift detected by the increase of TNFα and IFNγ when the same cells are subsequently (day 2) exposed to oral pathogen P. gingivalis. DISCUSSION: By extrapolating these results, we suggest that chronic infections, such as TB and leprosy, could generate a systemic immunological shift that can affect other inflammatory processes such the one present in PD. We propose that the presence and severity of PD should be explored as a proxy for inflammatory status or competence when reconstructing the health profile in past populations.


Assuntos
Inflamação/imunologia , Inflamação/microbiologia , Hanseníase/microbiologia , Mycobacterium leprae/imunologia , Mycobacterium tuberculosis/imunologia , Tuberculose/microbiologia , Arqueologia , Citocinas/imunologia , Citocinas/metabolismo , Humanos , Leucócitos Mononucleares , Mycobacterium leprae/metabolismo , Mycobacterium tuberculosis/metabolismo , Porphyromonas gingivalis/imunologia
20.
s.l; Elsevier; 2017. 10 p. tab, graf.
Não convencional em Inglês | SES-SP, HANSEN, SESSP-ILSLPROD, SES-SP, SESSP-ILSLACERVO, SES-SP | ID: biblio-1052567

RESUMO

Our previous study has demonstrated that IL-10 may modulate both indoleamine 2,3-dioxygenase (IDO) and CD163 expression in lepromatous leprosy (LL) cells, favoring Mycobacterium leprae persistence through induction of regulatory pathways and iron storage. Here, we observed that in LL lesion cells there is an increase in the expression of proteins involved in iron metabolism such as hemoglobin (Hb), haptoglobin, heme oxygenase 1 and transferrin receptor 1 (TfR1) when compared to tuberculoid leprosy (BT) cells. We also found increased iron deposits and diminished expression of the iron exporter ferroportin 1 in LL lesion cells. Hemin, but not FeSO stimulation, was able to enhance M. leprae viability by a mechanism that involves IDO. Analysis of cell phenotype in lesions demonstrated a predominance of M2 markers in LL when compared with BT lesion cells. A positive correlation between CD163 and PPARG with the bacillary index (BI) was observed. In contrast, TNF, STAT1 and CSF2 presented a negative correlation with the BI. In summary, this study demonstrates that iron may regulate IDO expression by a mechanism that involves IL-10, which may contribute for the predominance of M2-like phenotype in LL lesions that favors the phagocytosis and maintenance of M. leprae in host cells.


Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Immunoblotting , Hanseníase Virchowiana/metabolismo , Hanseníase Virchowiana/microbiologia , Técnicas Imunoenzimáticas , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Indolamina-Pirrol 2,3,-Dioxigenase/fisiologia , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Ferro/fisiologia , Ferro/metabolismo , Mycobacterium leprae/fisiologia , Mycobacterium leprae/metabolismo
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