RESUMO
During tuberculosis (TB), migration of dendritic cells (DCs) from the site of infection to the draining lymph nodes is known to be impaired, hindering the rapid development of protective T-cell-mediated immunity. However, the mechanisms involved in the delayed migration of DCs during TB are still poorly defined. Here, we found that infection of DCs with Mycobacterium tuberculosis (Mtb) triggers HIF1A-mediated aerobic glycolysis in a TLR2-dependent manner, and that this metabolic profile is essential for DC migration. In particular, the lactate dehydrogenase inhibitor oxamate and the HIF1A inhibitor PX-478 abrogated Mtb-induced DC migration in vitro to the lymphoid tissue-specific chemokine CCL21, and in vivo to lymph nodes in mice. Strikingly, we found that although monocytes from TB patients are inherently biased toward glycolysis metabolism, they differentiate into poorly glycolytic and poorly migratory DCs compared with healthy subjects. Taken together, these data suggest that because of their preexisting glycolytic state, circulating monocytes from TB patients are refractory to differentiation into migratory DCs, which may explain the delayed migration of these cells during the disease and opens avenues for host-directed therapies for TB.
Assuntos
Movimento Celular , Células Dendríticas , Glicólise , Subunidade alfa do Fator 1 Induzível por Hipóxia , Monócitos , Mycobacterium tuberculosis , Tuberculose , Células Dendríticas/metabolismo , Células Dendríticas/imunologia , Monócitos/metabolismo , Monócitos/imunologia , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Mycobacterium tuberculosis/imunologia , Animais , Tuberculose/imunologia , Tuberculose/metabolismo , Tuberculose/microbiologia , Camundongos , Receptor 2 Toll-Like/metabolismo , Camundongos Endogâmicos C57BL , FemininoRESUMO
Mycobacterium tuberculosis (Mtb) regulates the macrophage metabolic state to thrive in the host, yet the responsible mechanisms remain elusive. Macrophage activation toward the microbicidal (M1) program depends on the HIF-1α-mediated metabolic shift from oxidative phosphorylation (OXPHOS) toward glycolysis. Here, we ask whether a tuberculosis (TB) microenvironment changes the M1 macrophage metabolic state. We expose M1 macrophages to the acellular fraction of tuberculous pleural effusions (TB-PEs) and find lower glycolytic activity, accompanied by elevated levels of OXPHOS and bacillary load, compared to controls. The eicosanoid fraction of TB-PE drives these metabolic alterations. HIF-1α stabilization reverts the effect of TB-PE by restoring M1 metabolism. Furthermore, Mtb-infected mice with stabilized HIF-1α display lower bacillary loads and a pronounced M1-like metabolic profile in alveolar macrophages (AMs). Collectively, we demonstrate that lipids from a TB-associated microenvironment alter the M1 macrophage metabolic reprogramming by hampering HIF-1α functions, thereby impairing control of Mtb infection.
Assuntos
Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Lipídeos/farmacologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Mycobacterium tuberculosis/metabolismo , Tuberculose Pleural/metabolismo , Animais , Carga Bacteriana , Eicosanoides/farmacologia , Feminino , Glicólise/efeitos dos fármacos , Interações Hospedeiro-Patógeno , Humanos , Ativação de Macrófagos , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Fosforilação Oxidativa/efeitos dos fármacos , Consumo de Oxigênio/efeitos dos fármacos , Derrame Pleural , Tuberculose Pleural/microbiologiaRESUMO
The ability of Mycobacterium tuberculosis (Mtb) to persist inside host cells relies on metabolic adaptation, like the accumulation of lipid bodies (LBs) in the so-called foamy macrophages (FM), which are favorable to Mtb. The activation state of macrophages is tightly associated to different metabolic pathways, such as lipid metabolism, but whether differentiation towards FM differs between the macrophage activation profiles remains unclear. Here, we aimed to elucidate whether distinct macrophage activation states exposed to a tuberculosis-associated microenvironment or directly infected with Mtb can form FM. We showed that the triggering of signal transducer and activator of transcription 6 (STAT6) in interleukin (IL)-4-activated human macrophages (M(IL-4)) prevents FM formation induced by pleural effusion from patients with tuberculosis. In these cells, LBs are disrupted by lipolysis, and the released fatty acids enter the ß-oxidation (FAO) pathway fueling the generation of ATP in mitochondria. Accordingly, murine alveolar macrophages, which exhibit a predominant FAO metabolism, are less prone to become FM than bone marrow derived-macrophages. Interestingly, direct infection of M(IL-4) macrophages with Mtb results in the establishment of aerobic glycolytic pathway and FM formation, which could be prevented by FAO activation or inhibition of the hypoxia-inducible factor 1-alpha (HIF-1α)-induced glycolytic pathway. In conclusion, our results demonstrate that Mtb has a remarkable capacity to induce FM formation through the rewiring of metabolic pathways in human macrophages, including the STAT6-driven alternatively activated program. This study provides key insights into macrophage metabolism and pathogen subversion strategies.
Assuntos
Células Espumosas/microbiologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Metabolismo dos Lipídeos , Macrófagos/microbiologia , Mycobacterium tuberculosis/patogenicidade , Animais , Gotículas Lipídicas/metabolismo , Ativação de Macrófagos/fisiologia , Macrófagos/metabolismo , Masculino , Camundongos Endogâmicos BALB C , Mycobacterium tuberculosis/fisiologia , Tuberculose/microbiologiaRESUMO
While tuberculosis (TB) is a risk factor in HIV-1-infected individuals, the mechanisms by which Mycobacterium tuberculosis (Mtb) worsens HIV-1 pathogenesis remain scarce. We showed that HIV-1 infection is exacerbated in macrophages exposed to TB-associated microenvironments due to tunneling nanotube (TNT) formation. To identify molecular factors associated with TNT function, we performed a transcriptomic analysis in these macrophages, and revealed the up-regulation of Siglec-1 receptor. Siglec-1 expression depends on Mtb-induced production of type I interferon (IFN-I). In co-infected non-human primates, Siglec-1 is highly expressed by alveolar macrophages, whose abundance correlates with pathology and activation of IFN-I/STAT1 pathway. Siglec-1 localizes mainly on microtubule-containing TNT that are long and carry HIV-1 cargo. Siglec-1 depletion decreases TNT length, diminishes HIV-1 capture and cell-to-cell transfer, and abrogates the exacerbation of HIV-1 infection induced by Mtb. Altogether, we uncover a deleterious role for Siglec-1 in TB-HIV-1 co-infection and open new avenues to understand TNT biology.
Assuntos
HIV-1/patogenicidade , Interferon Tipo I/imunologia , Macrófagos Alveolares/imunologia , Macrófagos Alveolares/virologia , Lectina 1 Semelhante a Ig de Ligação ao Ácido Siálico/genética , Tuberculose Pulmonar/imunologia , Animais , Células Cultivadas , Coinfecção/imunologia , Feminino , Perfilação da Expressão Gênica , Infecções por HIV , Humanos , Macaca mulatta , Masculino , Nanotubos , Lectina 1 Semelhante a Ig de Ligação ao Ácido Siálico/imunologiaRESUMO
Tuberculosis (TB) is an infectious disease, caused by Mycobacterium tuberculosis, primarily affecting the lungs. The M. tuberculosis strain of the Haarlem family named M was responsible for a large multidrug-resistant TB (MDR-TB) outbreak in Buenos Aires. This outbreak started in the early 1990s and in the mid 2000s still accounted for 29% of all MDR-TB cases in Argentina. By contrast, a clonal variant of strain M, named 410, has caused a single tuberculosis case since the onset of the outbreak. The molecular bases of the high epidemiological fitness of the M strain remain unclear. To assess its unique molecular properties, herein, we performed a comparative protein and lipid analysis of a representative clone of the M strain (Mp) and the nonprosperous M variant 410. We also evaluated their growth in low pH. The variant 410 had higher levels of latency proteins under standard conditions and delayed growth at low pH, suggesting that it is more sensitive to stress stimuli than Mp. Moreover, Mp showed higher levels of mycolic acids covalently attached to the cell wall and lower accumulation of free mycolic acids in the outer layer than the 410 strain. The low expression of latency proteins together with the reduced content of surface mycolic acids may facilitate Mp to evade the host immune responses.
Assuntos
Farmacorresistência Bacteriana Múltipla , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/isolamento & purificação , Tuberculose Resistente a Múltiplos Medicamentos/epidemiologia , Argentina/epidemiologia , Proteínas de Bactérias , Parede Celular/metabolismo , Surtos de Doenças , Concentração de Íons de Hidrogênio , Ácidos Micólicos/metabolismo , Proteômica , Espectrometria de Massas em Tandem , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/microbiologiaRESUMO
The fitness of a pathogen results from the interaction of multiple factors favoring either epidemiological success or failure. Herein, we studied the performance of the M strain, a highly successful multidrug resistant Mycobacterium tuberculosis genotype, and its non-prosperous variant, the 410 strain, in activated human monocyte-derived macrophages. Both strains showed comparable ability to induce necrotic cell death and to survive in apoptotic macrophages. Of the various macrophage activation conditions tested, none led to an enhanced control of the outbreak strain. The combination of 1,25(OH)2 vitaminD3 and IFN-γ favored significantly the control of the non-prosperous 410 strain. These observations indicate that the ability of the M strain to survive within the hostile intracellular milieu is conserved, and the overall fitness cost paid by this genotype would be low. Our results provide additional evidence on bacterial traits that may have contributed to the epidemiological success of the M strain.
Assuntos
Antituberculosos/farmacologia , Epidemias , Macrófagos/fisiologia , Mycobacterium tuberculosis/efeitos dos fármacos , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia , Argentina/epidemiologia , Doadores de Sangue , Morte Celular , Farmacorresistência Bacteriana Múltipla , Humanos , Mycobacterium tuberculosis/genética , Estaurosporina/farmacologia , Tuberculose Resistente a Múltiplos Medicamentos/epidemiologiaRESUMO
The tuberculosis (TB) bacillus, Mycobacterium tuberculosis (Mtb), and HIV-1 act synergistically; however, the mechanisms by which Mtb exacerbates HIV-1 pathogenesis are not well known. Using in vitro and ex vivo cell culture systems, we show that human M(IL-10) anti-inflammatory macrophages, present in TB-associated microenvironment, produce high levels of HIV-1. In vivo, M(IL-10) macrophages are expanded in lungs of co-infected non-human primates, which correlates with disease severity. Furthermore, HIV-1/Mtb co-infected patients display an accumulation of M(IL-10) macrophage markers (soluble CD163 and MerTK). These M(IL-10) macrophages form direct cell-to-cell bridges, which we identified as tunneling nanotubes (TNTs) involved in viral transfer. TNT formation requires the IL-10/STAT3 signaling pathway, and targeted inhibition of TNTs substantially reduces the enhancement of HIV-1 cell-to-cell transfer and overproduction in M(IL-10) macrophages. Our study reveals that TNTs facilitate viral transfer and amplification, thereby promoting TNT formation as a mechanism to be explored in TB/AIDS potential therapeutics.
Assuntos
Infecções por HIV/complicações , Interleucina-10/metabolismo , Macrófagos/patologia , Nanotubos , Fator de Transcrição STAT3/metabolismo , Tuberculose Pulmonar/complicações , Adulto , Idoso , Animais , Células Cultivadas , Coinfecção/patologia , Coinfecção/virologia , Feminino , Infecções por HIV/imunologia , Infecções por HIV/patologia , Infecções por HIV/virologia , Humanos , Macaca mulatta , Ativação de Macrófagos , Macrófagos/virologia , Masculino , Pessoa de Meia-Idade , Mycobacterium tuberculosis , Transdução de Sinais , Tuberculose Pulmonar/imunologia , Tuberculose Pulmonar/patologia , Replicação Viral , Adulto JovemAssuntos
Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Mycobacterium tuberculosis/efeitos dos fármacos , Proteínas Tirosina Quinases/farmacologia , Pirazóis/farmacologia , Pirimidinas/farmacologia , Receptores de Antígenos de Linfócitos T gama-delta/metabolismo , Linfócitos T/efeitos dos fármacos , Linfócitos T/metabolismo , Adenina/análogos & derivados , Tirosina Quinase da Agamaglobulinemia/antagonistas & inibidores , Humanos , PiperidinasRESUMO
DC-SIGN (CD209/CLEC4L) is a C-type lectin receptor (CLR) that serves as a reliable cell-surface marker of interleukin 4 (IL-4)-activated human macrophages [M(IL-4)], which historically represent the most studied subset within the M2 spectrum of macrophage activation. Although DC-SIGN plays important roles in Mycobacterium tuberculosis (Mtb) interactions with dendritic cells, its contribution to the Mtb-macrophage interaction remains poorly understood. Since high levels of IL-4 are correlated with tuberculosis (TB) susceptibility and progression, we investigated the role of DC-SIGN in M(IL-4) macrophages in the TB context. First, we demonstrate that DC-SIGN expression is present both in CD68+ macrophages found in tuberculous pulmonary lesions of non-human primates, and in the CD14+ cell population isolated from pleural effusions obtained from TB patients (TB-PE). Likewise, we show that DC-SIGN expression is accentuated in M(IL-4) macrophages derived from peripheral blood CD14+ monocytes isolated from TB patients, or in macrophages stimulated with acellular TB-PE, arguing for the pertinence of DC-SIGN-expressing macrophages in TB. Second, using a siRNA-mediated gene silencing approach, we performed a transcriptomic analysis of DC-SIGN-depleted M(IL-4) macrophages and revealed the upregulation of pro-inflammatory signals in response to challenge with Mtb, as compared to control cells. This pro-inflammatory gene signature was confirmed by RT-qPCR, cytokine/chemokine-based protein array, and ELISA analyses. We also found that inactivation of DC-SIGN renders M(IL-4) macrophages less permissive to Mtb intracellular growth compared to control cells, despite the equal level of bacteria uptake. Last, at the molecular level, we show that DC-SIGN interferes negatively with the pro-inflammatory response and control of Mtb intracellular growth mediated by another CLR, Dectin-1 (CLEC7A). Collectively, this study highlights a dual role for DC-SIGN as, on the one hand, being a host factor granting advantage for Mtb to parasitize macrophages and, on the other hand, representing a molecular switch to turn off the pro-inflammatory response in these cells to prevent potential immunopathology associated to TB.
Assuntos
Moléculas de Adesão Celular/metabolismo , Lectinas Tipo C/metabolismo , Macrófagos/imunologia , Macrófagos/metabolismo , Mycobacterium tuberculosis/imunologia , Receptores de Superfície Celular/metabolismo , Tuberculose/imunologia , Tuberculose/metabolismo , Animais , Moléculas de Adesão Celular/genética , Sobrevivência Celular/genética , Sobrevivência Celular/imunologia , Citocinas/metabolismo , Feminino , Expressão Gênica , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Humanos , Mediadores da Inflamação/metabolismo , Lectinas Tipo C/genética , Macaca mulatta , Macrófagos/microbiologia , Monócitos/imunologia , Monócitos/metabolismo , Fagocitose/imunologia , Receptores de Superfície Celular/genética , Tuberculose/genética , Tuberculose/microbiologiaRESUMO
The ability of Mycobacterium tuberculosis (Mtb) to persist in its human host relies on numerous immune evasion strategies, such as the deregulation of the lipid metabolism leading to the formation of foamy macrophages (FM). Yet, the specific host factors leading to the foamy phenotype of Mtb-infected macrophages remain unknown. Herein, we aimed to address whether host cytokines contribute to FM formation in the context of Mtb infection. Our approach is based on the use of an acellular fraction of tuberculous pleural effusions (TB-PE) as a physiological source of local factors released during Mtb infection. We found that TB-PE induced FM differentiation as observed by the increase in lipid bodies, intracellular cholesterol, and expression of the scavenger receptor CD36, as well as the enzyme acyl CoA:cholesterol acyl transferase (ACAT). Importantly, interleukin-10 (IL-10) depletion from TB-PE prevented the augmentation of all these parameters. Moreover, we observed a positive correlation between the levels of IL-10 and the number of lipid-laden CD14+ cells among the pleural cells in TB patients, demonstrating that FM differentiation occurs within the pleural environment. Downstream of IL-10 signaling, we noticed that the transcription factor signal transducer and activator of transcription 3 was activated by TB-PE, and its chemical inhibition prevented the accumulation of lipid bodies and ACAT expression in macrophages. In terms of the host immune response, TB-PE-treated macrophages displayed immunosuppressive properties and bore higher bacillary loads. Finally, we confirmed our results using bone marrow-derived macrophage from IL-10-/- mice demonstrating that IL-10 deficiency partially prevented foamy phenotype induction after Mtb lipids exposure. In conclusion, our results evidence a role of IL-10 in promoting the differentiation of FM in the context of Mtb infection, contributing to our understanding of how alterations of the host metabolic factors may favor pathogen persistence.
Assuntos
Acetil-CoA C-Acetiltransferase/imunologia , Regulação Enzimológica da Expressão Gênica/imunologia , Interleucina-10/imunologia , Mycobacterium tuberculosis/imunologia , Derrame Pleural/imunologia , Fator de Transcrição STAT3/imunologia , Esterol O-Aciltransferase , Tuberculose Pleural/imunologia , Regulação para Cima/imunologia , Acetil-CoA C-Acetiltransferase/genética , Animais , Feminino , Células Espumosas , Humanos , Interleucina-10/genética , Masculino , Camundongos , Camundongos Knockout , Mycobacterium tuberculosis/genética , Derrame Pleural/genética , Derrame Pleural/patologia , Fator de Transcrição STAT3/genética , Tuberculose Pleural/genética , Tuberculose Pleural/patologiaRESUMO
Determining bacterial fitness represents a major challenge and no single parameter can accurately predict the ability of a certain pathogen to succeed. The M strain of Mycobacterium tuberculosis managed to spread and establish in the community and caused the largest multidrug-resistant tuberculosis outbreak in Latin America. We have previously shown that the M strain can manipulate the host immune response, but we still have no direct evidence, other than epidemiology, that can account for the enhanced fitness of the M strain. Our objective was to further characterize the performance of the outbreak strain M in different fitness assays. Two main aspects were evaluated: (1) molecular characterization of selected isolates from the M outbreak and related strains and (2) comparative fitness and in vivo performance of representative M strain isolates vs. the non-prosperous M strain variant 410. Our approach confirmed the multifaceted nature of fitness. Altogether, we conclude that the epidemiologically abortive strain 410 was vulnerable to drug-driven pressure, a weak competitor, and a stronger inductor of protective response in vivo. Conversely, the isolate 6548, representative of the M outbreak peak, had a growth disadvantage but performed very well in competition and induced lung damage at advanced stages in spite of reaching relatively low CFU counts. Integration of these observations supports the idea that the M strain managed to find a unique path to success.
Assuntos
Surtos de Doenças , Aptidão Genética , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/isolamento & purificação , Proteínas de Bactérias/genética , RNA Polimerases Dirigidas por DNA/genética , Genoma Bacteriano , Genótipo , Humanos , Mutação , Mycobacterium tuberculosis/patogenicidade , Tuberculose Resistente a Múltiplos Medicamentos , Virulência/genéticaRESUMO
RATIONALE: In addition to their well-known function as antibody-producing cells, B lymphocytes can markedly influence the course of infectious or noninfectious diseases via antibody-independent mechanisms. In tuberculosis (TB), B cells accumulate in lungs, yet their functional contribution to the host response remains poorly understood. OBJECTIVES: To document the role of B cells in TB in an unbiased manner. METHODS: We generated the transcriptome of B cells isolated from Mycobacterium tuberculosis (Mtb)-infected mice and validated the identified key pathways using in vitro and in vivo assays. The obtained data were substantiated using B cells from pleural effusion of patients with TB. MEASUREMENTS AND MAIN RESULTS: B cells isolated from Mtb-infected mice displayed a STAT1 (signal transducer and activator of transcription 1)-centered signature, suggesting a role for IFNs in B-cell response to infection. B cells stimulated in vitro with Mtb produced type I IFN, via a mechanism involving the innate sensor STING (stimulator of interferon genes), and antagonized by MyD88 (myeloid differentiation primary response 88) signaling. In vivo, B cells expressed type I IFN in the lungs of Mtb-infected mice and, of clinical relevance, in pleural fluid from patients with TB. Type I IFN expression by B cells induced an altered polarization of macrophages toward a regulatory/antiinflammatory profile in vitro. In vivo, increased provision of type I IFN by B cells in a murine model of B cell-restricted Myd88 deficiency correlated with an enhanced accumulation of regulatory/antiinflammatory macrophages in Mtb-infected lungs. CONCLUSIONS: Type I IFN produced by Mtb-stimulated B cells favors macrophage polarization toward a regulatory/antiinflammatory phenotype during Mtb infection.
Assuntos
Linfócitos B/metabolismo , Interferon Tipo I/metabolismo , Macrófagos/metabolismo , Tuberculose/metabolismo , Animais , Modelos Animais de Doenças , Humanos , Pulmão/metabolismo , Pulmão/microbiologia , Camundongos , Camundongos Endogâmicos C57BL , Mycobacterium tuberculosis , Transdução de Sinais , Baço/metabolismo , Baço/microbiologiaRESUMO
M strain, the most prevalent multidrug-resistant strain of Mycobacterium tuberculosis (Mtb) in Argentina, has mounted mechanisms to evade innate immune response. The role of human bronchial epithelium in Mtb infection remains unknown as well as its crosstalk with neutrophils (PMN). In this work, we evaluate whether M and H37Rv strains invade and replicate within bronchial epithelial cell line Calu-6 and how conditioned media (CM) derived from infected cells alter PMN responses. We demonstrated that M infects and survives within Calu-6 without promoting death. CM from M-infected Calu-6 (M-CM) did not attract PMN in correlation with its low IL-8 content compared to H37Rv-CM. Also, PMN activation and ROS production in response to irradiated H37Rv were impaired after treatment with M-CM due to the lack of TNF-α. Interestingly, M-CM increased H37Rv replication in PMN which would allow the spreading of mycobacteria upon PMN death and sustain IL-8 release. Thus, our results indicate that even at low invasion/replication rate within Calu-6, M induces the secretion of factors altering the crosstalk between these nonphagocytic cells and PMN, representing an evasion mechanism developed by M strain to persist in the host. These data provide new insights on the role of bronchial epithelium upon M infection.
Assuntos
Interleucina-8/metabolismo , Mycobacterium tuberculosis/efeitos dos fármacos , Neutrófilos/efeitos dos fármacos , Neutrófilos/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Quimiocinas/metabolismo , Quimiotaxia/efeitos dos fármacos , Meios de Cultivo Condicionados/farmacologia , Citocinas/metabolismo , Citometria de Fluxo , Humanos , Imunidade Inata/efeitos dos fármacos , Fagocitose/efeitos dos fármacosRESUMO
C5a anaphylatoxin is a component of the complement system involved in the modulation of T-cell polarization. Herein we investigated whether C5a receptors, C5aR and C5L2, modulate the cytokine profiles induced by Mycobacterium tuberculosis (Mtb). We analyzed the impact of both receptors on T helper cell polarization induced by the multidrug resistant outbreak strain named M, which is a poor IFN-γ inducer compared with the laboratory strain H37Rv. To this aim, we first blocked C5aR or C5L2 of peripheral blood monocytes (Mo) from patients with tuberculosis and healthy donors, then we stimulated the Mo either with H37Rv or the M strain, and finally we analyzed cytokine profiles of Mo/macrophages (MΦ) and CD4+ T-cells. We found that: (i) Mtb modulated the expression of both C5a receptors, (ii) C5aR inhibited the expansion of CD4+IFN-γ+ lymphocytes stimulated by the M strain but not by H37Rv, (iii) both receptors modulated the Mo/MΦ cytokine expression induced by Mtb. We conclude that C5aR, but not C5L2, plays a role in T helper cell polarization induced by Mtb and that this effect is strain- and donor-dependent. We speculate that the epidemiologically successful M strain takes advantage of this C5aR-mediated inhibition of Th1 polarization to survive within the host.
Assuntos
Citocinas/imunologia , Surtos de Doenças , Mycobacterium tuberculosis/imunologia , Receptor da Anafilatoxina C5a/imunologia , Células Th1/imunologia , Tuberculose Resistente a Múltiplos Medicamentos/imunologia , Adolescente , Adulto , Idoso , Estudos de Casos e Controles , Células Cultivadas , Citocinas/metabolismo , Feminino , Genótipo , Interações Hospedeiro-Patógeno , Humanos , Macrófagos/imunologia , Macrófagos/metabolismo , Macrófagos/microbiologia , Masculino , Pessoa de Meia-Idade , Monócitos/imunologia , Monócitos/metabolismo , Monócitos/microbiologia , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/patogenicidade , Fenótipo , Receptor da Anafilatoxina C5a/metabolismo , Receptores de Quimiocinas/imunologia , Receptores de Quimiocinas/metabolismo , Células Th1/metabolismo , Células Th1/microbiologia , Fatores de Tempo , Tuberculose Resistente a Múltiplos Medicamentos/metabolismo , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia , Adulto JovemRESUMO
Globally, about 4.5% of new tuberculosis (TB) cases are multi-drug-resistant (MDR), i.e. resistant to the two most powerful first-line anti-TB drugs. Indeed, 480,000 people developed MDR-TB in 2015 and 190,000 people died because of MDR-TB. The MDR Mycobacterium tuberculosis M family, which belongs to the Haarlem lineage, is highly prosperous in Argentina and capable of building up further drug resistance without impairing its ability to spread. In this study, we sequenced the whole genomes of a highly prosperous M-family strain (Mp) and its contemporary variant, strain 410, which produced only one recorded tuberculosis case in the last two decades. Previous reports have demonstrated that Mp induced dysfunctional CD8+ cytotoxic T cell activity, suggesting that this strain has the ability to evade the immune response against M. tuberculosis. Comparative analysis of Mp and 410 genomes revealed non-synonymous polymorphisms in eleven genes and five intergenic regions with polymorphisms between both strains. Some of these genes and promoter regions are involved in the metabolism of cell wall components, others in drug resistance and a SNP in Rv1861, a gene encoding a putative transglycosylase that produces a truncated protein in Mp. The mutation in Rv3787c, a putative S-adenosyl-l-methionine-dependent methyltransferase, is conserved in all of the other prosperous M strains here analysed and absent in non-prosperous M strains. Remarkably, three polymorphic promoter regions displayed differential transcriptional activity between Mp and 410. We speculate that the observed mutations/polymorphisms are associated with the reported higher capacity of Mp for modulating the host's immune response.
Assuntos
Proteínas de Bactérias/genética , Farmacorresistência Bacteriana Múltipla/genética , Mycobacterium tuberculosis/genética , Polimorfismo de Nucleotídeo Único , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia , Antituberculosos/uso terapêutico , Regulação Bacteriana da Expressão Gênica , Genoma Bacteriano , Genótipo , Interações Hospedeiro-Patógeno , Humanos , Mutação , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/imunologia , Mycobacterium tuberculosis/patogenicidade , Fenótipo , Regiões Promotoras Genéticas , Tuberculose Resistente a Múltiplos Medicamentos/diagnóstico , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/imunologiaRESUMO
Beside its key diagnostic value, the humoral immune response is thought to play a protective role in hantavirus pulmonary syndrome. However, little is known about the cell source of these antibodies during ongoing human infection. Herein we characterized B-cell subsets circulating in Andes-virus-infected patients. A notable potent plasmablast (PB) response that increased 100-fold over the baseline levels was observed around 1 week after the onset of symptoms. These PB present a CD3neg CD19low CD20neg CD38hi CD27hi CD138+/- IgA+/- surface phenotype together with the presence of cytoplasmic functional immunoglobulins. They are large lymphocytes (lymphoblasts) morphologically coincident with the 'immunoblast-like' cells that have been previously described during blood cytology examinations of hantavirus-infected patients. Immunoreactivity analysis of white blood cell lysates suggests that some circulating PB are virus-specific but we also observed a significant increase of reactivity against virus-unrelated antigens, which suggests a possible bystander effect by polyclonal B-cell activation. The presence of this large and transient PB response raises the question as to whether these cells might have a protective or pathological role during the ongoing hantavirus pulmonary syndrome and suggest their practical application as a diagnostic/prognostic biomarker.
Assuntos
Subpopulações de Linfócitos B/imunologia , Síndrome Pulmonar por Hantavirus/imunologia , Orthohantavírus/imunologia , Plasmócitos/imunologia , Células Precursoras de Linfócitos B/imunologia , Doença Aguda , Adulto , Anticorpos Antivirais/sangue , Antígenos CD/metabolismo , Autoantígenos/imunologia , Subpopulações de Linfócitos B/virologia , Biomarcadores/metabolismo , Proliferação de Células , Feminino , Síndrome Pulmonar por Hantavirus/diagnóstico , Humanos , Imunoglobulina A/metabolismo , Ativação Linfocitária , Masculino , Pessoa de Meia-Idade , Plasmócitos/virologia , Células Precursoras de Linfócitos B/virologia , Adulto JovemRESUMO
Tuberculosis (TB) is a complex disease, and the success of the bacterium depends on its ability to evade the immune response. Previously, we determined that Mycobacterium tuberculosis (Mtb) impairs the function of dendritic cells (DC), promoting the generation of cells that are poor stimulators of mycobacterial antigen-specific CD4T cells, which are required to control this persistent infection. In this study, we aimed to determine the mechanisms by which monocyte-derived DCs differentiated in the presence of Mtb (MtbDC) may impact on the proliferation of specific anti-mycobacterial T cells. We found that the presence of Mtb during monocyte-derived DC differentiation favours T helper (Th) 2 and Th17 polarization, in detriment of a Th1 response, compared to DC mature with Mtb. The bias on T cell polarization was associated to the profile of C-type lectin receptors expression found in MtbDC (DC-SIGNlow/MRlow/Dectin-1high). Alternatively, MtbDC release Mtb antigens (Ag) that can be taken up and presented by bystander DC, promoting the proliferation of CD4T cells, but to a lesser extent than direct presentation by Mtb-matured DC. In summary, we have further characterized the generation of MtbDC as an effective evasion strategy driven by the pathogen, leading to the inhibition of Ag-presentation and bias of T cell polarization towards Th2 and Th17 profiles, features which partially explain the persistence of Mtb in the host.
Assuntos
Antígenos de Bactérias/imunologia , Antígenos de Bactérias/metabolismo , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Mycobacterium tuberculosis/imunologia , Células Th17/imunologia , Células Th2/imunologia , Adulto , Doadores de Sangue , Proliferação de Células , Voluntários Saudáveis , Humanos , Pessoa de Meia-IdadeRESUMO
The human CD14(+) monocyte compartment is composed by two subsets based on CD16 expression. We previously reported that this compartment is perturbed in tuberculosis (TB) patients, as reflected by the expansion of CD16(+) monocytes along with disease severity. Whether this unbalance is beneficial or detrimental to host defense remains to be elucidated. Here in the context of active TB, we demonstrate that human monocytes are predisposed to differentiate towards an anti-inflammatory (M2-like) macrophage activation program characterized by the CD16(+)CD163(+)MerTK(+)pSTAT3(+) phenotype and functional properties such as enhanced protease-dependent motility, pathogen permissivity and immunomodulation. This process is dependent on STAT3 activation, and loss-of-function experiments point towards a detrimental role in host defense against TB. Importantly, we provide a critical correlation between the abundance of the CD16(+)CD163(+)MerTK(+)pSTAT3(+) cells and the progression of the disease either at the local level in a non-human primate tuberculous granuloma context, or at the systemic level through the detection of the soluble form of CD163 in human sera. Collectively, this study argues for the pathogenic role of the CD16(+)CD163(+)MerTK(+)pSTAT3(+) monocyte-to-macrophage differentiation program and its potential as a target for TB therapy, and promotes the detection of circulating CD163 as a potential biomarker for disease progression and monitoring of treatment efficacy.
Assuntos
Imunomodulação , Interleucina-10/metabolismo , Monócitos/imunologia , Monócitos/patologia , Receptores de IgG/metabolismo , Fator de Transcrição STAT3/metabolismo , Tuberculose/imunologia , Tuberculose/patologia , HumanosRESUMO
Circulating monocytes (Mo) play an essential role in the host immune response to chronic infections. We previously demonstrated that CD16(pos) Mo were expanded in TB (tuberculosis) patients, correlated with disease severity and were refractory to dendritic cell differentiation. In the present study, we investigated whether human Mo subsets (CD16(neg) and CD16(pos)) differed in their ability to influence the early inflammatory response against Mycobacterium tuberculosis. We first evaluated the capacity of the Mo subsets to migrate and engage a microbicidal response in vitro. Accordingly, CD16(neg) Mo were more prone to migrate in response to different mycobacteria-derived gradients, were more resistant to M. tuberculosis intracellular growth and produced higher reactive oxygen species than their CD16(pos) counterpart. To assess further the functional dichotomy among the human Mo subsets, we carried out an in vivo analysis by adapting a hybrid mouse model (SCID/Beige, where SCID is severe combined immunodeficient) to transfer each Mo subset, track their migratory fate during M. tuberculosis infection, and determine their impact on the host immune response. In M. tuberculosis-infected mice, the adoptively transferred CD16(neg) Mo displayed a higher lung migration index, induced a stronger pulmonary infiltration of murine leucocytes expressing pro- and anti-inflammatory cytokines, and significantly decreased the bacterial burden, in comparison with CD16(pos) Mo. Collectively, our results indicate that human Mo subsets display divergent biological roles in the context of M. tuberculosis infection, a scenario in which CD16(neg) Mo may contribute to the anti-mycobacterial immune response, whereas CD16(pos) Mo might promote microbial resilience, shedding light on a key aspect of the physiopathology of TB disease.
Assuntos
Pulmão/imunologia , Monócitos/imunologia , Mycobacterium tuberculosis/imunologia , Tuberculose Pulmonar/imunologia , Animais , Carga Bacteriana , Células Cultivadas , Quimiotaxia de Leucócito , Modelos Animais de Doenças , Proteínas Ligadas por GPI/imunologia , Proteínas Ligadas por GPI/metabolismo , Interações Hospedeiro-Patógeno , Humanos , Pulmão/metabolismo , Pulmão/microbiologia , Camundongos SCID , Monócitos/classificação , Monócitos/metabolismo , Monócitos/microbiologia , Monócitos/transplante , Mycobacterium tuberculosis/crescimento & desenvolvimento , Mycobacterium tuberculosis/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Receptores de IgG/imunologia , Receptores de IgG/metabolismo , Explosão Respiratória , Fatores de Tempo , Tuberculose Pulmonar/sangue , Tuberculose Pulmonar/microbiologiaRESUMO
Molecular epidemiology has revealed that Mycobacterium tuberculosis (Mtb), formerly regarded as highly conserved species, displays a considerable degree of genetic variability that can influence the outcome of the disease as well as the innate and adaptive immune response. Recent studies have demonstrated that Mtb families found worldwide today differ in pathology, transmissibility, virulence, and development of immune response. By proteomic approaches seven proteins that were differentially expressed between a local clinical isolate from Latin-American-Mediterranean (LAM) and from Haarlem (H) lineages were identified. In order to analyze the immunogenic ability, recombinant Rv2241, Rv0009, Rv0407, and Rv2624c proteins were produced for testing specific antibody responses. We found that these proteins induced humoral immune responses in patients with drug-sensitive and drug-resistant tuberculosis with substantial cross-reactivity among the four proteins. Moreover, such reactivity was also correlated with anti-Mtb-cell surface IgM, but not with anti-ManLAM, anti-PPD, or anti-Mtb-surface IgG antibodies. Therefore, the present results describe new Mtb antigens with potential application as biomarkers of TB.