Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
1.
bioRxiv ; 2023 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-37873458

RESUMO

Rationale: Accurate TB diagnosis is hampered by the variable efficacy of the widely-used Ziehl-Neelsen (ZN) staining method to identify Mycobacterium tuberculosis ( Mtb ) acid-fast bacilli (AFB). Here, we sought to circumvent this current limitation through direct detection of Mtb mRNA. Objectives: To employ RNAscope to determine the spatial distribution of Mtb mRNA within tuberculous human tissue, to appraise ZN-negative tissue from confirmed TB patients, and to provide proof-of-concept of RNAscope as a platform to inform TB diagnosis and Mtb biology. Methods: We examined ante- and postmortem human TB tissue using RNAscope to detect Mtb mRNA and a dual ZN/immunohistochemistry staining approach to identify AFB and bacilli producing antigen 85B (Ag85B). Measurements and main results: We adapted RNAscope for Mtb and identified intact and disintegrated Mtb bacilli and intra- and extracellular Mtb mRNA. Mtb mRNA was distributed zonally within necrotic and non-necrotic granulomas. We also found Mtb mRNA within, and adjacent to, necrotic granulomas in ZN-negative lung tissue and in Ag85B-positive bronchial epithelium. Intriguingly, we observed accumulation of Mtb mRNA and Ag85B in the cytoplasm of host cells. Notably, many AFB were negative for Ag85B staining. Mtb mRNA was observed in ZN-negative antemortem lymph node biopsies. Conclusions: RNAscope has diagnostic potential and can guide therapeutic intervention as it detects Mtb mRNA and morphology in ZN-negative tissues from TB patients, and Mtb mRNA in ZN-negative antemortem biopsies, respectively. Lastly, our data provide evidence that at least two phenotypically distinct populations of Mtb bacilli exist in vivo .

2.
Lab Invest ; 92(11): 1541-52, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22964851

RESUMO

Non-tuberculous mycobacterial (NTM) infections occur in both immunocompromised and immunocompetent hosts and are an increasingly recognized cause of morbidity and mortality. The hallmark of pulmonary mycobacterial infections is the formation of granuloma in the lung. Our study focuses on the role of heme oxygenase-1 (HO-1), a cytoprotective enzyme, in the regulation of granuloma development and maturation following infection with Mycobacterium avium. We examined the role of HO-1 in regulating monocyte chemoattractant protein-1 (MCP-1) and chemokine receptor 2 (CCR2), two molecules involved in monocyte-macrophage cell trafficking after infection. We showed that RAW 264.7 mouse monocytes exposed to M. avium expressed HO-1 and MCP-1. Inhibition of HO by zinc protoporphyrin-IX led to inhibition of MCP-1 and increased expression of CCR2, its cognate receptor. HO-1⁻/⁻ mice did not develop organized granuloma in their lungs, had higher lung colony forming unit of M. avium when infected with intratracheal M. avium, and had loose collections of inflammatory cells in the lung parenchyma. Mycobacteria were found only inside defined granulomas but not outside granuloma in the lungs of HO-1⁺/⁺ mice. In HO-1⁻/⁻ mice, mycobacteria were also found in the liver and spleen and showed increased mortality. Peripheral blood monocytes isolated from GFP⁺ mice and given intravenously to HO-1⁺/⁺ mice localized into tight granulomas, while in HO-1⁻/⁻ mice they remained diffusely scattered in areas of parenchymal inflammation. Higher MCP-1 levels were found in bronchoalveolar lavage fluid of M. avium infected HO-1(-/-) mice and CCR2 expression was higher in HO-1⁻/⁻ alveolar macrophages when compared with HO-1⁺/⁺ mice. CCR2 expression localized to granuloma in HO-1⁺/⁺ mice but not in the HO-1⁻/⁻ mice. These findings strongly suggest that HO-1 plays a protective role in the control of M. avium infection.


Assuntos
Quimiocina CCL2/metabolismo , Granuloma/enzimologia , Heme Oxigenase-1/metabolismo , Proteínas de Membrana/metabolismo , Receptores CCR2/metabolismo , Tuberculose Pulmonar/enzimologia , Animais , Linhagem Celular , Contagem de Colônia Microbiana , Granuloma/microbiologia , Pulmão/patologia , Camundongos , Camundongos Knockout , Mycobacterium avium , Protoporfirinas , RNA Mensageiro/metabolismo , Tuberculose Pulmonar/microbiologia , Tuberculose Pulmonar/patologia
3.
J Clin Invest ; 131(10)2021 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-33848273

RESUMO

T cell immunity is essential for the control of tuberculosis (TB), an important disease of the lung, and is generally studied in humans using peripheral blood cells. Mounting evidence, however, indicates that tissue-resident memory T cells (Trms) are superior at controlling many pathogens, including Mycobacterium tuberculosis (M. tuberculosis), and can be quite different from those in circulation. Using freshly resected lung tissue, from individuals with active or previous TB, we identified distinct CD4+ and CD8+ Trm-like clusters within TB-diseased lung tissue that were functional and enriched for IL-17-producing cells. M. tuberculosis-specific CD4+ T cells producing TNF-α, IL-2, and IL-17 were highly expanded in the lung compared with matched blood samples, in which IL-17+ cells were largely absent. Strikingly, the frequency of M. tuberculosis-specific lung T cells making IL-17, but not other cytokines, inversely correlated with the plasma IL-1ß levels, suggesting a potential link with disease severity. Using a human granuloma model, we showed the addition of either exogenous IL-17 or IL-2 enhanced immune control of M. tuberculosis and was associated with increased NO production. Taken together, these data support an important role for M. tuberculosis-specific Trm-like, IL-17-producing cells in the immune control of M. tuberculosis in the human lung.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Interleucina-17/imunologia , Pulmão/imunologia , Mycobacterium tuberculosis/imunologia , Tuberculose Pulmonar/imunologia , Linfócitos T CD4-Positivos/patologia , Feminino , Humanos , Interleucina-1beta/imunologia , Interleucina-2/imunologia , Pulmão/patologia , Masculino , Óxido Nítrico/imunologia , Tuberculose Pulmonar/patologia
4.
J Clin Invest ; 130(1): 214-230, 2020 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-31763997

RESUMO

Unconventional T cells that recognize mycobacterial antigens are of great interest as potential vaccine targets against tuberculosis (TB). This includes donor-unrestricted T cells (DURTs), such as mucosa-associated invariant T cells (MAITs), CD1-restricted T cells, and γδ T cells. We exploited the distinctive nature of DURTs and γδ T cell receptors (TCRs) to investigate the involvement of these T cells during TB in the human lung by global TCR sequencing. Making use of surgical lung resections, we investigated the distribution, frequency, and characteristics of TCRs in lung tissue and matched blood from individuals infected with TB. Despite depletion of MAITs and certain CD1-restricted T cells from the blood, we found that the DURT repertoire was well preserved in the lungs, irrespective of disease status or HIV coinfection. The TCRδ repertoire, in contrast, was highly skewed in the lungs, where it was dominated by Vδ1 and distinguished by highly localized clonal expansions, consistent with the nonrecirculating lung-resident γδ T cell population. These data show that repertoire sequencing is a powerful tool for tracking T cell subsets during disease.


Assuntos
Pulmão/imunologia , Receptores de Antígenos de Linfócitos T gama-delta/imunologia , Subpopulações de Linfócitos T/imunologia , Tuberculose Pulmonar/imunologia , Adolescente , Adulto , Idoso , Regiões Determinantes de Complementaridade/imunologia , Feminino , Infecções por HIV/imunologia , Humanos , Masculino , Pessoa de Meia-Idade , Mucosa/imunologia , Células T Matadoras Naturais/imunologia , Doadores de Tecidos , Tuberculose Pulmonar/cirurgia , Adulto Jovem
5.
Elife ; 72018 11 16.
Artigo em Inglês | MEDLINE | ID: mdl-30444490

RESUMO

How Mycobacterium tuberculosis (Mtb) rewires macrophage energy metabolism to facilitate survival is poorly characterized. Here, we used extracellular flux analysis to simultaneously measure the rates of glycolysis and respiration in real time. Mtb infection induced a quiescent energy phenotype in human monocyte-derived macrophages and decelerated flux through glycolysis and the TCA cycle. In contrast, infection with the vaccine strain, M. bovis BCG, or dead Mtb induced glycolytic phenotypes with greater flux. Furthermore, Mtb reduced the mitochondrial dependency on glucose and increased the mitochondrial dependency on fatty acids, shifting this dependency from endogenous fatty acids in uninfected cells to exogenous fatty acids in infected macrophages. We demonstrate how quantifiable bioenergetic parameters of the host can be used to accurately measure and track disease, which will enable rapid quantifiable assessment of drug and vaccine efficacy. Our findings uncover new paradigms for understanding the bioenergetic basis of host metabolic reprogramming by Mtb.


Assuntos
Ciclo do Ácido Cítrico/genética , Ácidos Graxos/metabolismo , Glucose/metabolismo , Glicólise/genética , Interações Hospedeiro-Patógeno , Macrófagos/microbiologia , Mycobacterium tuberculosis/metabolismo , Diferenciação Celular/efeitos dos fármacos , Respiração Celular , Genes Reporter , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Humanos , Macrófagos/metabolismo , Metaboloma , Mitocôndrias/metabolismo , Mycobacterium bovis/crescimento & desenvolvimento , Mycobacterium bovis/metabolismo , Mycobacterium tuberculosis/crescimento & desenvolvimento , Células THP-1 , Acetato de Tetradecanoilforbol/farmacologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA