RESUMEN
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.
Asunto(s)
Movimiento Celular , Células Dendríticas , Glucólisis , Subunidad alfa del Factor 1 Inducible por Hipoxia , Monocitos , Mycobacterium tuberculosis , Tuberculosis , Células Dendríticas/metabolismo , Células Dendríticas/inmunología , Monocitos/metabolismo , Monocitos/inmunología , Humanos , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Mycobacterium tuberculosis/inmunología , Animales , Tuberculosis/inmunología , Tuberculosis/metabolismo , Tuberculosis/microbiología , Ratones , Receptor Toll-Like 2/metabolismo , Ratones Endogámicos C57BL , FemeninoRESUMEN
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.
Asunto(s)
Células Espumosas/microbiología , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Metabolismo de los Lípidos , Macrófagos/microbiología , Mycobacterium tuberculosis/patogenicidad , Animales , Gotas Lipídicas/metabolismo , Activación de Macrófagos/fisiología , Macrófagos/metabolismo , Masculino , Ratones Endogámicos BALB C , Mycobacterium tuberculosis/fisiología , Tuberculosis/microbiologíaRESUMEN
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.
Asunto(s)
Farmacorresistencia Bacteriana Múltiple , Mycobacterium tuberculosis/efectos de los fármacos , Mycobacterium tuberculosis/aislamiento & purificación , Tuberculosis Resistente a Múltiples Medicamentos/epidemiología , Argentina/epidemiología , Proteínas Bacterianas , Pared Celular/metabolismo , Brotes de Enfermedades , Concentración de Iones de Hidrógeno , Ácidos Micólicos/metabolismo , Proteómica , Espectrometría de Masas en Tándem , Tuberculosis Resistente a Múltiples Medicamentos/tratamiento farmacológico , Tuberculosis Resistente a Múltiples Medicamentos/microbiologíaRESUMEN
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.
Asunto(s)
Antituberculosos/farmacología , Epidemias , Macrófagos/fisiología , Mycobacterium tuberculosis/efectos de los fármacos , Tuberculosis Resistente a Múltiples Medicamentos/microbiología , Argentina/epidemiología , Donantes de Sangre , Muerte Celular , Farmacorresistencia Bacteriana Múltiple , Humanos , Mycobacterium tuberculosis/genética , Estaurosporina/farmacología , Tuberculosis Resistente a Múltiples Medicamentos/epidemiologíaRESUMEN
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.
Asunto(s)
Infecciones por VIH/complicaciones , Interleucina-10/metabolismo , Macrófagos/patología , Nanotubos , Factor de Transcripción STAT3/metabolismo , Tuberculosis Pulmonar/complicaciones , Adulto , Anciano , Animales , Células Cultivadas , Coinfección/patología , Coinfección/virología , Femenino , Infecciones por VIH/inmunología , Infecciones por VIH/patología , Infecciones por VIH/virología , Humanos , Macaca mulatta , Activación de Macrófagos , Macrófagos/virología , Masculino , Persona de Mediana Edad , Mycobacterium tuberculosis , Transducción de Señal , Tuberculosis Pulmonar/inmunología , Tuberculosis Pulmonar/patología , Replicación Viral , Adulto JovenAsunto(s)
Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Mycobacterium tuberculosis/efectos de los fármacos , Proteínas Tirosina Quinasas/farmacología , Pirazoles/farmacología , Pirimidinas/farmacología , Receptores de Antígenos de Linfocitos T gamma-delta/metabolismo , Linfocitos T/efectos de los fármacos , Linfocitos T/metabolismo , Adenina/análogos & derivados , Agammaglobulinemia Tirosina Quinasa/antagonistas & inhibidores , Humanos , PiperidinasRESUMEN
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.
Asunto(s)
Acetil-CoA C-Acetiltransferasa/inmunología , Regulación Enzimológica de la Expresión Génica/inmunología , Interleucina-10/inmunología , Mycobacterium tuberculosis/inmunología , Derrame Pleural/inmunología , Factor de Transcripción STAT3/inmunología , Esterol O-Aciltransferasa , Tuberculosis Pleural/inmunología , Regulación hacia Arriba/inmunología , Acetil-CoA C-Acetiltransferasa/genética , Animales , Femenino , Células Espumosas , Humanos , Interleucina-10/genética , Masculino , Ratones , Ratones Noqueados , Mycobacterium tuberculosis/genética , Derrame Pleural/genética , Derrame Pleural/patología , Factor de Transcripción STAT3/genética , Tuberculosis Pleural/genética , Tuberculosis Pleural/patologíaRESUMEN
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.
Asunto(s)
Interleucina-8/metabolismo , Mycobacterium tuberculosis/efectos de los fármacos , Neutrófilos/efectos de los fármacos , Neutrófilos/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Quimiocinas/metabolismo , Quimiotaxis/efectos de los fármacos , Medios de Cultivo Condicionados/farmacología , Citocinas/metabolismo , Citometría de Flujo , Humanos , Inmunidad Innata/efectos de los fármacos , Fagocitosis/efectos de los fármacosRESUMEN
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.
Asunto(s)
Subgrupos de Linfocitos B/inmunología , Síndrome Pulmonar por Hantavirus/inmunología , Orthohantavirus/inmunología , Células Plasmáticas/inmunología , Células Precursoras de Linfocitos B/inmunología , Enfermedad Aguda , Adulto , Anticuerpos Antivirales/sangre , Antígenos CD/metabolismo , Autoantígenos/inmunología , Subgrupos de Linfocitos B/virología , Biomarcadores/metabolismo , Proliferación Celular , Femenino , Síndrome Pulmonar por Hantavirus/diagnóstico , Humanos , Inmunoglobulina A/metabolismo , Activación de Linfocitos , Masculino , Persona de Mediana Edad , Células Plasmáticas/virología , Células Precursoras de Linfocitos B/virología , Adulto JovenRESUMEN
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.
Asunto(s)
Pulmón/inmunología , Monocitos/inmunología , Mycobacterium tuberculosis/inmunología , Tuberculosis Pulmonar/inmunología , Animales , Carga Bacteriana , Células Cultivadas , Quimiotaxis de Leucocito , Modelos Animales de Enfermedad , Proteínas Ligadas a GPI/inmunología , Proteínas Ligadas a GPI/metabolismo , Interacciones Huésped-Patógeno , Humanos , Pulmón/metabolismo , Pulmón/microbiología , Ratones SCID , Monocitos/clasificación , Monocitos/metabolismo , Monocitos/microbiología , Monocitos/trasplante , Mycobacterium tuberculosis/crecimiento & desarrollo , Mycobacterium tuberculosis/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Receptores de IgG/inmunología , Receptores de IgG/metabolismo , Estallido Respiratorio , Factores de Tiempo , Tuberculosis Pulmonar/sangre , Tuberculosis Pulmonar/microbiologíaRESUMEN
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.
Asunto(s)
Proteínas Bacterianas , Regulación Bacteriana de la Expresión Génica/fisiología , Fenómenos Inmunogenéticos , Mycobacterium tuberculosis , Tuberculosis Resistente a Múltiples Medicamentos , Factores de Virulencia , Adulto , Anticuerpos Antibacterianos/sangre , Anticuerpos Antibacterianos/inmunología , Proteínas Bacterianas/biosíntesis , Proteínas Bacterianas/inmunología , Proteínas Bacterianas/metabolismo , Biomarcadores/sangre , Reacciones Cruzadas/genética , Reacciones Cruzadas/inmunología , Femenino , Humanos , Inmunoglobulina M/sangre , Inmunoglobulina M/inmunología , Masculino , Persona de Mediana Edad , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/inmunología , Mycobacterium tuberculosis/metabolismo , Proteómica , Tuberculosis Resistente a Múltiples Medicamentos/sangre , Tuberculosis Resistente a Múltiples Medicamentos/genética , Tuberculosis Resistente a Múltiples Medicamentos/inmunología , Factores de Virulencia/biosíntesis , Factores de Virulencia/genética , Factores de Virulencia/inmunologíaRESUMEN
In human tuberculosis (TB), CD8+ T cells contribute to host defense by the release of Th1 cytokines and the direct killing of Mycobacterium tuberculosis (Mtb)-infected macrophages via granule exocytosis pathway or the engagement of receptors on target cells. Previously we demonstrated that strain M, the most prevalent multidrug-resistant (MDR) Mtb strain in Argentine, is a weak inducer of IFN-γ and elicits a remarkably low CD8-dependent cytotoxic T cell activity (CTL). In contrast, the closely related strain 410, which caused a unique case of MDR-TB, elicits a CTL response similar to H37Rv. In this work we extend our previous study investigating some parameters that can account for this discrepancy. We evaluated the expressions of the lytic molecules perforin, granzyme B and granulysin and the chemokine CCL5 in CD8+ T cells as well as activation markers CD69 and CD25 and IL-2 expression in CD4+ and CD8+ T cells stimulated with strains H37Rv, M and 410. Our results demonstrate that M-stimulated CD8+ T cells from purified protein derivative positive healthy donors show low intracellular expression of perforin, granzyme B, granulysin and CCL5 together with an impaired ability to form conjugates with autologous M-pulsed macrophages. Besides, M induces low CD69 and IL-2 expression in CD4+ and CD8+ T cells, being CD69 and IL-2 expression closely associated. Furthermore, IL-2 addition enhanced perforin and granulysin expression as well as the degranulation marker CD107 in M-stimulated CD8+ T cells, making no differences with cells stimulated with strains H37Rv or 410. Thus, our results highlight the role of IL-2 in M-induced CTL activity that drives the proper activation of CD8+ T cells as well as CD4+ T cells collaboration.
Asunto(s)
Citotoxicidad Inmunológica , Farmacorresistencia Bacteriana Múltiple , Activación de Linfocitos , Mycobacterium tuberculosis/inmunología , Linfocitos T Citotóxicos/inmunología , Adulto , Antígenos CD/genética , Antígenos CD/metabolismo , Antígenos de Diferenciación de Linfocitos T/genética , Antígenos de Diferenciación de Linfocitos T/metabolismo , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/metabolismo , Células Cultivadas , Quimiocina CCL5/genética , Quimiocina CCL5/metabolismo , Femenino , Granzimas/genética , Granzimas/metabolismo , Humanos , Interleucina-2/genética , Interleucina-2/metabolismo , Subunidad alfa del Receptor de Interleucina-2/genética , Subunidad alfa del Receptor de Interleucina-2/metabolismo , Lectinas Tipo C/genética , Lectinas Tipo C/metabolismo , Masculino , Mycobacterium tuberculosis/efectos de los fármacos , Mycobacterium tuberculosis/genética , Perforina/genética , Perforina/metabolismo , Linfocitos T Citotóxicos/metabolismoRESUMEN
Mycobacterium tuberculosis has a considerable degree of genetic variability resulting in different epidemiology and disease outcomes. We evaluated the pathogen-host cell interaction of two genetically closely-related multidrug-resistant M. tuberculosis strains of the Haarlem family, namely the strain M, responsible for an extensive multidrug-resistant tuberculosis outbreak, and its kin strain 410 which caused a single case in two decades. Intracellular growth and cytokine responses were evaluated in human monocyte-derived macrophages and dU937 macrophage-like cells. In monocyte-derived macrophages, strain M grew more slowly and induced lower levels of TNF-α and IL-10 than 410, contrasting with previous studies with other strains, where a direct correlation was observed between increased intracellular growth and epidemiological success. On the other hand, in dU937 cells, no difference in growth was observed between both strains, and strain M induced significantly higher TNF-α levels than strain 410. We found that both cell models differed critically in the expression of receptors for M. tuberculosis entry, which might explain the different infection outcomes. Our results in monocyte-derived macrophages suggest that strain M relies on a modest replication rate and cytokine induction, keeping a state of quiescence and remaining rather unnoticed by the host. Collectively, our results underscore the impact of M. tuberculosis intra-species variations on the outcome of host cell infection and show that results can differ depending on the in vitro infection model.
Asunto(s)
Macrófagos/microbiología , Mycobacterium tuberculosis/genética , Tuberculosis Resistente a Múltiples Medicamentos/microbiología , Análisis de Varianza , Línea Celular Tumoral , Proliferación Celular , Células Cultivadas , Citocinas/metabolismo , Femenino , Interacciones Huésped-Patógeno , Humanos , Macrófagos/citología , Macrófagos/metabolismo , Masculino , Modelos Biológicos , Mycobacterium tuberculosis/patogenicidadRESUMEN
A number of studies have determined the contribution of Th1 and Th2 responses to the protective immunity and pathology of Mycobacterium bovis infection. However, much of that information is derived from experimentally infecting cattle with M. bovis and few data from naturally infected animals are available. The aim of this study was to characterize the immunological profile towards M. bovis antigens of naturally infected cattle by measurement of cytokine mRNA expression in PBMC, and to determine which lymphocyte subsets are involved in recall responses of PBMC from M. bovis infected cattle to M. bovis antigens. Consistent with data from cattle experimentally infected with M. bovis, naturally infected animals were found to display a Th1 cytokine profile in response to M. bovis PPDB stimulation. Production of IFN-gamma mRNA by PBMC after PPDB stimulation statistically distinguishes between infected and healthy herds, suggesting that this molecule is usable as an M. bovis-infection marker. As happens in experimentally infected cows, CD4, CD8 and gammadeltaTCR cells from a herd naturally infected with M. bovis are the predominant T cell subsets expanded in response to PPDB.
Asunto(s)
Antígenos Bacterianos/inmunología , Mycobacterium bovis/inmunología , Tuberculosis Bovina/inmunología , Animales , Antígenos Bacterianos/genética , Bovinos , Células Cultivadas , Citocinas/genética , Citocinas/inmunología , Expresión Génica , Leucocitos Mononucleares/inmunología , Leucocitos Mononucleares/microbiología , Mycobacterium bovis/genética , Subgrupos de Linfocitos T/inmunología , Tuberculosis Bovina/genética , Tuberculosis Bovina/microbiologíaAsunto(s)
/biosíntesis , Activación de Linfocitos , /inmunología , /metabolismo , Factor de Necrosis Tumoral alfa/fisiología , Lepra/inmunología , Lepra/microbiología , Interferón gamma/fisiología , Leucocitos Mononucleares/inmunología , Linfocitos T Citotóxicos/inmunología , Linfocitos T Citotóxicos/microbiología , Macrófagos/inmunología , Mycobacterium leprae/inmunología , Receptores de IgG/biosíntesis , Pruebas Inmunológicas de CitotoxicidadRESUMEN
In the present study we evaluated the contribution of CD4 and CD8 T cells on the antigen-specific cytotoxic activity induced by whole Mycobacterium leprae in leprosy patients and normal controls (N) as well as the modulation of this activity by some cytokines. Peripheral blood mononuclear cells (PBMC) from N or from leprosy patients were stimulated with antigen in the presence or absence of cytokines for 7 days. M. leprae-stimulated PBMC were depleted of CD4 or CD8 antigen-bearing cells and employed as effector cells in a 4-hr [31Cr]-release assay against autologous M. leprae-pulsed macrophages. Our results demonstrate that both CD4 and CD8 T cells contribute to M. leprae-induced cytotoxic activity, with differences observed in paucibacillary (PB) and multibacillary (MB) patients. CD8-mediated cytotoxic activity is higher than that of CD4 cells in PB patients, while in MB patients CD4 cytotoxicity is predominant. Our data also demonstrate that the generation of CD4 and CD8 cytotoxic T lymphocytes (CTL) can be modulated differentially by interleukin-4 (IL-4), IL-6, gamma interferon (IFN-gamma), or IL-2. Although MB patients developed the lowest CTL response, cytokines such as IL-6 plus IL-2 or IFN-gamma were able to generate both CD4 and CD8 cytotoxic T cells from MB patients. In PB patients, IL-6 plus IFN-gamma displayed the highest stimulation on CD8 effector cells. Thus, an important role may be assigned to IL-6, together with IL-2 or IFN-gamma, in the differentiation of M. leprae-specific CTL effector cells.
Asunto(s)
Lepra Dimorfa/inmunología , Lepra Tuberculoide/inmunología , Lepra Lepromatosa/inmunología , /inmunología , /inmunologíaRESUMEN
El objetivo de este estudio fue evaluar la producción de citoquinas por células mononucleares periféricas (CMP) obtenidas de pacientes con lepra, cuando estas células son estimuladas con ConA, PPD o Myconacterium leprae. Medimos IL-2, IL-4, IFN- y e IL-6 en sobrenadantes libres de células, por enzimoinmunoensayos. Nuestros resultados no sugieren una clara associación entre una forma clínica de lepra y un perfil de secreción de citoquinas de tipo Th1 o Th2 en las CMP de los pacientes con lepra. (AU)
Asunto(s)
Humanos , Masculino , Femenino , Adolescente , Adulto , Persona de Mediana Edad , Anciano , RESEARCH SUPPORT, NON-U.S. GOVT , Citocinas/biosíntesis , Lepra/metabolismo , Células Sanguíneas/metabolismo , Ensayo de Inmunoadsorción Enzimática , Lepra/inmunología , Macrófagos/metabolismo , Mycobacterium lepraeRESUMEN
El objetivo de este estudio fue evaluar la producción de citoquinas por células mononucleares periféricas (CMP) obtenidas de pacientes con lepra, cuando estas células son estimuladas con ConA, PPD o Myconacterium leprae. Medimos IL-2, IL-4, IFN- y e IL-6 en sobrenadantes libres de células, por enzimoinmunoensayos. Nuestros resultados no sugieren una clara associación entre una forma clínica de lepra y un perfil de secreción de citoquinas de tipo Th1 o Th2 en las CMP de los pacientes con lepra.