RESUMO
Mycobacterium leprae (M. leprae), the causative agent of leprosy, parasitizes within the foamy or enlarged phagosome of macrophages where rich lipids accumulate. Although the mechanisms for lipid accumulation in the phagosome have been clarified, it is still unclear how such large amounts of lipids escape degradation. To further explore underlying mechanisms involved in lipid catabolism in M. leprae-infected host cells, we examined the expression of hormone-sensitive lipase (HSL), a key enzyme in fatty acid mobilization and lipolysis, in human macrophage THP-1 cells. We found that infection by live M. leprae significantly suppressed HSL expression levels. This suppression was not observed with dead M. leprae or latex beads. Macrophage activation by peptidoglycan (PGN), the ligand for toll-like receptor 2 (TLR2), increased HSL expression; however, live M. leprae suppressed this increase. HSL expression was abolished in the slit-skin smear specimens from patients with lepromatous and borderline leprosy. In addition, the recovery of HSL expression was observed in patients who experienced a lepra reaction, which is a cell-mediated, delayed-type hypersensitivity immune response, or in patients who were successfully treated with multi-drug therapy. These results suggest that M. leprae suppresses lipid degradation through inhibition of HSL expression, and that the monitoring of HSL mRNA levels in slit-skin smear specimens may be a useful indicator of patient prognosis.
Assuntos
Hanseníase/enzimologia , Metabolismo dos Lipídeos , Macrófagos/enzimologia , Macrófagos/metabolismo , Mycobacterium leprae/fisiologia , Esterol Esterase/metabolismo , Regulação para Baixo , Humanos , Hanseníase/genética , Hanseníase/metabolismo , Hanseníase/microbiologia , Macrófagos/microbiologia , Fagossomos/metabolismo , Esterol Esterase/genética , Receptor 2 Toll-Like/genética , Receptor 2 Toll-Like/metabolismoRESUMO
Leprosy has affected humans for millennia and remains an important health problem worldwide, as evidenced by nearly 250 000 new cases detected every year. It is a chronic infectious disorder, caused by Mycobacterium leprae, that primarily affects the skin and peripheral nerves. Recent advances in basic science have improved our knowledge of the disease. Variation in the cellular immune response is the basis of a range of clinical manifestations. The introduction of multidrug therapy has significantly contributed to a decrease in the prevalence of the disease. However, leprosy control activities, including monitoring and prevention programs, must be maintained.
Assuntos
Hanseníase , Mycobacterium leprae , Animais , Dapsona/uso terapêutico , Quimioterapia Combinada , Feminino , Humanos , Hansenostáticos/uso terapêutico , Hanseníase/tratamento farmacológico , Hanseníase/epidemiologia , Hanseníase/patologia , Hanseníase/transmissão , Masculino , Mycobacterium leprae/citologia , Mycobacterium leprae/efeitos dos fármacos , Mycobacterium leprae/isolamento & purificação , Doenças do Sistema Nervoso Periférico/microbiologia , Prevalência , Resultado do TratamentoRESUMO
The whole-genome sequence analysis of Mycobacterium leprae, which was completed in 2001, revealed the characteristics of this microbe's genomic structure. Half of the M. leprae genome consists of a limited number of protein-coding genes and the rest comprises non-coding regions and pseudogenes. We performed membrane array and tiling array analyses to analyze the gene-expression profile of the M. leprae genome and found that pseudogenes and non-coding regions were expressed similarly to coding regions at the RNA level. The RNA expressions were confirmed by real-time PCR analysis. Expression of these RNAs in clinical samples showed varying patterns among patients, thus indicating that the analysis of RNA expression patterns, including non-coding regions and pseudogenes, may be useful for understanding the pathological state, prognosis, and assessment of therapeutic progress in leprosy.
Assuntos
Perfilação da Expressão Gênica , Genoma Bacteriano , Hanseníase/microbiologia , Hanseníase/patologia , Mycobacterium leprae/genética , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Genoma Bacteriano/genética , Humanos , Mycobacterium leprae/metabolismo , Prognóstico , Pseudogenes/genética , RNA Bacteriano/genética , RNA Bacteriano/metabolismo , RNA não Traduzido/genética , RNA não Traduzido/metabolismoRESUMO
BACKGROUND: Identification of pathogen DNA from archaeological human remains is a powerful tool in demonstrating that the infectious disease existed in the past. However, it is very difficult to detect trace amounts of DNA remnants attached to the human skeleton, especially from those buried in a humid atmosphere with a relatively high environmental temperature such as in Asia. METHODOLOGY/PRINCIPAL FINDINGS: Here we demonstrate Mycobacterium leprae DNA from archaeological skeletal remains in Japan by polymerase chain reaction, DNA sequencing and single nucleotide polymorphism (SNP) analysis. In addition, we have established a highly sensitive method of detecting DNA using a combination of whole genome amplification and polymerase chain reaction, or WGA-PCR, which provides superior sensitivity and specificity in detecting DNA from trace amounts of skeletal materials. CONCLUSION/SIGNIFICANCE: We have detected M. leprae DNA in archaeological skeletal remains for the first time in the Far East. Its SNP genotype corresponded to type 1; the first detected case worldwide of ancient M. leprae DNA. We also developed a highly sensitive method to detect ancient DNA by utilizing whole genome amplification.