RESUMEN
TRIM21 is an interferon-stimulated E3 ligase that controls the activity of pattern-recognition signaling via ubiquitination of interferon regulatory factors and DDX41. Previous studies on the role of TRIM21 in innate immune responses have yielded contradictory results, suggesting that the role of TRIM21 is cell specific. Here, we report that bone-marrow-derived macrophages (BMDMs) generated from Trim21-/- mice have reduced expression of mature macrophage markers. Reflecting their reduced differentiation in response to macrophage colony-stimulating factor (M-CSF), Trim21-/- BMDMs had decreased expression of M-CSF signature genes. Although Trim21-/- BMDMs responded normally to Toll-like receptor 9 (TLR9) activation, they produced lower levels of pro-inflammatory cytokines in response to the TLR2 agonist PAM3CSK4. In line with this, the response to infection with the Bacillus Calmette-Guérin strain of Mycobacterium bovis was also diminished in Trim21-/- BMDMs. Our results indicate that TRIM21 controls responses to TLR2 agonists.
Asunto(s)
Citocinas/metabolismo , Mediadores de Inflamación/metabolismo , Macrófagos/metabolismo , Ribonucleoproteínas/metabolismo , Receptor Toll-Like 2/metabolismo , Animales , Diferenciación Celular , Células Cultivadas , Interacciones Huésped-Patógeno , Lipopéptidos/farmacología , Factor Estimulante de Colonias de Macrófagos/farmacología , Macrófagos/efectos de los fármacos , Macrófagos/inmunología , Macrófagos/microbiología , Ratones Endogámicos C57BL , Ratones Noqueados , Mycobacterium bovis/inmunología , Mycobacterium bovis/patogenicidad , Fenotipo , Ribonucleoproteínas/deficiencia , Ribonucleoproteínas/genética , Transducción de Señal , Receptor Toll-Like 2/agonistas , Receptor Toll-Like 2/genéticaRESUMEN
STAT3 is a master regulator of the immune responses. Here we show that M. tuberculosis-infected stat3fl/fl lysm cre mice, defective for STAT3 in myeloid cells, contained lower bacterial load in lungs and spleens, reduced granuloma extension but higher levels of pulmonary neutrophils. STAT3-deficient macrophages showed no improved control of intracellular mycobacterial growth. Instead, protection associated to elevated ability of stat3fl/fl lysm cre antigen-presenting cells (APCs) to release IL-6 and IL-23 and to stimulate IL-17 secretion by mycobacteria-specific T cells. The increased IL-17 secretion accounted for the improved control of infection since neutralization of IL-17 receptor A in stat3fl/fl lysm cre mice hampered bacterial control. APCs lacking SOCS3, which inhibits STAT3 activation via several cytokine receptors, were poor inducers of priming and of the IL-17 production by mycobacteria-specific T cells. In agreement, socs3fl/fl cd11c cre mice deficient of SOCS3 in DCs showed increased susceptibility to M. tuberculosis infection. While STAT3 in APCs hampered IL-17 responses, STAT3 in mycobacteria-specific T cells was critical for IL-17 secretion, while SOCS3 in T cells impeded IL-17 secretion. Altogether, STAT3 signalling in myeloid cells is deleterious in the control of infection with M. tuberculosis.
Asunto(s)
Mycobacterium tuberculosis/inmunología , Células Mieloides/metabolismo , Factor de Transcripción STAT3/genética , Linfocitos T/inmunología , Tuberculosis/inmunología , Animales , Células Cultivadas , Macrófagos/inmunología , Macrófagos/metabolismo , Ratones , Ratones Transgénicos , Factor de Transcripción STAT3/metabolismo , Transducción de Señal/genética , Tuberculosis/genética , Tuberculosis/metabolismoRESUMEN
Conditional gene targeting using the bacteriophage-derived Cre recombinase is widely applied for functional gene studies in mice. Mice transgenic for Cre under the control of the lck gene promoter are used to study the role of loxP-targeted genes in T cell development and function. In this article, we show a striking 65% reduction in cellularity, preferential development of γδ versus αß T cells, and increased expression of IL-7R in the thymus of mice expressing Cre under the proximal lck promoter (lck-cre(+) mice). The transition from CD4/CD8 double-negative to double-positive cells was blocked, and lck-cre(+) double-positive cells were more prone to apoptosis and showed higher levels of Cre expression. Importantly, numbers of naive T cells were reduced in spleens and lymph nodes of lck-cre(+) mice. In contrast, frequencies of γδ T cells, CD44(+)CD62L(-) effector T cells, and Foxp3(+) regulatory T cells were elevated, as was the frequency of IFN-γ-secreting CD4(+) and CD8(+) T cells. A literature survey of 332 articles that used lck-cre(+) mice for deletion of floxed genes indicated that results are statistically influenced by the control used (lck-cre(+) or lck-cre(-)), more frequently resembling the lck-cre(+) phenotype described in this article if lck-cre(-) controls were used. Altogether, care should be taken when interpreting published results and to properly control targeted gene deletions using the lck-cre(+) strain.
Asunto(s)
Linfocitos T CD8-positivos/metabolismo , Integrasas/metabolismo , Regiones Promotoras Genéticas , Proteínas Serina-Treonina Quinasas/genética , Subgrupos de Linfocitos T/metabolismo , Timo/citología , Animales , Apoptosis , Linfocitos T CD8-positivos/inmunología , Diferenciación Celular/genética , Eliminación de Gen , Integrasas/genética , Interferón gamma/inmunología , Interferón gamma/metabolismo , Ratones , Ratones Transgénicos , Proteínas Serina-Treonina Quinasas/metabolismo , Receptores de Interleucina-7/genética , Subgrupos de Linfocitos T/inmunología , Linfocitos T Reguladores/inmunología , Linfocitos T Reguladores/metabolismo , Timo/inmunologíaRESUMEN
In our review, we address the role of signal transducer and activator of transcription-3 (STAT3) and suppressor of cytokine signaling-3 (SOCS3) in the outcome of Mycobacterium tuberculosis infection, focusing on functions of these molecules in regulating the biology of myeloid and lymphoid cells. The STAT3 transcription factor has paradoxical roles: mainly activating an anti-inflammatory program in myeloid cells while promoting the differentiation and activation of inflammatory T cells. STAT3 is a major player in all phases of T cell responses, including T cell subset differentiation, T cell activation, and generation of memory. We review the roles of cytokines that activate, or are activated by, STAT3 during the infection with M. tuberculosis. SOCS3 inhibits STAT3 activation, by some but not all STAT3-activating cytokine receptors. Infection with M. tuberculosis also stimulates SOCS3 expression in phagocytes. Studies in different mouse models have proven the critical importance of SOCS3 in restraining inflammation and allowing optimal levels of protective immune responses against the infection. The accumulated data presented here suggest a relevant program coordinated by SOCS3 in different cell populations, which results in improved control of infection with M. tuberculosis. STAT3 and SOCS3 may thus be targeted to improve the control of infection with M. tuberculosis or the efficiency of vaccination.
Asunto(s)
Células Dendríticas/inmunología , Macrófagos/inmunología , Factor de Transcripción STAT3/inmunología , Proteínas Supresoras de la Señalización de Citocinas/inmunología , Linfocitos T/inmunología , Tuberculosis Pulmonar/inmunología , Animales , Citocinas/genética , Citocinas/inmunología , Células Dendríticas/microbiología , Células Dendríticas/patología , Regulación de la Expresión Génica , Interacciones Huésped-Patógeno , Humanos , Macrófagos/microbiología , Macrófagos/patología , Ratones , Mycobacterium tuberculosis/inmunología , Receptores de Citocinas/genética , Receptores de Citocinas/inmunología , Factor de Transcripción STAT3/genética , Transducción de Señal , Proteína 3 Supresora de la Señalización de Citocinas , Proteínas Supresoras de la Señalización de Citocinas/genética , Linfocitos T/microbiología , Linfocitos T/patología , Tuberculosis Pulmonar/genética , Tuberculosis Pulmonar/microbiología , Tuberculosis Pulmonar/patologíaRESUMEN
The obligate intracellular parasite Toxoplasma gondii can actively infect any nucleated cell type, including cells from the immune system. The rapid transfer of T. gondii from infected dendritic cells to effector natural killer (NK) cells may contribute to the parasite's sequestration and shielding from immune recognition shortly after infection. However, subversion of NK cell functions, such as cytotoxicity or production of proinflammatory cytokines, such as gamma interferon (IFN-γ), upon parasite infection might also be beneficial to the parasite. In the present study, we investigated the effects of T. gondii infection on NK cells. In vitro, infected NK cells were found to be poor at killing target cells and had reduced levels of IFN-γ production. This could be attributed in part to the inability of infected cells to form conjugates with their target cells. However, even upon NK1.1 cross-linking of NK cells, the infected NK cells also exhibited poor degranulation and IFN-γ production. Similarly, NK cells infected in vivo were also poor at killing target cells and producing IFN-γ. Increased levels of transforming growth factor ß production, as well as increased levels of expression of SHP-1 in the cytosol of infected NK cells upon infection, were observed in infected NK cells. However, the phosphorylation of STAT4 was not altered in infected NK cells, suggesting that transcriptional regulation mediates the reduced IFN-γ production, which was confirmed by quantitative PCR. These data suggest that infection of NK cells by T. gondii impairs NK cell recognition of target cells and cytokine release, two mechanisms that independently could enhance T. gondii survival.
Asunto(s)
Inmunomodulación , Células Asesinas Naturales/microbiología , Células Asesinas Naturales/fisiología , Toxoplasma/inmunología , Toxoplasmosis Animal/inmunología , Animales , Citotoxicidad Inmunológica , Células Dendríticas/inmunología , Células Dendríticas/microbiología , Interacciones Huésped-Parásitos , Interferón gamma/biosíntesis , Interferón gamma/inmunología , Células Asesinas Naturales/inmunología , Ratones , Fosforilación , Proteína Tirosina Fosfatasa no Receptora Tipo 6/biosíntesis , Proteína Tirosina Fosfatasa no Receptora Tipo 6/genética , Factor de Transcripción STAT4/metabolismo , Toxoplasma/fisiología , Factor de Crecimiento Transformador beta/biosíntesisRESUMEN
We have used humanized mice, in which human immune cells differentiate de novo from transplanted cord blood progenitor cells, to study the human immune responses to infection with Mycobacterium bovis bacillus Calmette-Guérin and Mycobacterium tuberculosis. Granulomas with a core containing giant cells, human CD68(+) macrophages, and high bacilli numbers surrounded by a layer of CD3(+) T cells and a fibrotic response encapsulating the lesions were observed in livers and lungs from bacillus Calmette-Guérin-infected humanized mice but not in nonhumanized infected controls. Paradoxically, humanized mice contained higher mycobacterial numbers in organs than nonhumanized controls. The enhancement of bacterial load was mediated by human CD4(+) cells and associated to an increased expression of Programmed Death-1 protein and CD57 on T cells, molecules associated with inhibition and senescence. The lesions from mice depleted of CD4(+) cells were scarcer, minimal, and irregular compared with those from mice depleted of CD8(+) cells or nondepleted controls. Granulomas of bacillus Calmette-Guérin-infected humanized mice administered with a TNF-neutralizing TNF receptor fusion molecule preserved their structure, but contained higher levels of intracellular bacilli. Extended necrosis was observed in granulomas from M. tuberculosis- but not bacillus Calmette-Guérin-infected humanized mice. Our data indicate that humanized mice can be used as a model to study the formation and maintenance of human granuloma in tuberculosis and other infectious or noninfectious diseases.
Asunto(s)
Linfocitos T CD4-Positivos/inmunología , Granuloma/inmunología , Mycobacterium bovis , Mycobacterium tuberculosis , Tuberculosis/inmunología , Animales , Trasplante de Células Madre de Sangre del Cordón Umbilical , Citometría de Flujo , Granuloma/complicaciones , Humanos , Inmunohistoquímica , Ratones , Ratones Transgénicos , Reacción en Cadena en Tiempo Real de la Polimerasa , Estadísticas no Paramétricas , Tuberculosis/complicacionesRESUMEN
Suppressor of cytokine signalling 3 (SOCS3) negatively regulates STAT3 activation in response to several cytokines such as those in the gp130-containing IL-6 receptor family. Thus, SOCS3 may play a major role in immune responses to pathogens. In the present study, the role of SOCS3 in M. tuberculosis infection was examined. All Socs3(fl/fl) LysM cre, Socs3(fl/fl) lck cre (with SOCS3-deficient myeloid and lymphoid cells, respectively) and gp130(F/F) mice, with a mutation in gp130 that impedes binding to SOCS3, showed increased susceptibility to infection with M. tuberculosis. SOCS3 binding to gp130 in myeloid cells conveyed resistance to M. tuberculosis infection via the regulation of IL-6/STAT3 signalling. SOCS3 was redundant for mycobacterial control by macrophages in vitro. Instead, SOCS3 expression in infected macrophages and DCs prevented the IL-6-mediated inhibition of TNF and IL-12 secretion and contributed to a timely CD4+ cell-dependent IFN-γ expression in vivo. In T cells, SOCS3 expression was essential for a gp130-independent control of infection with M. tuberculosis, but was neither required for the control of infection with attenuated M. bovis BCG nor for M. tuberculosis in BCG-vaccinated mice. Socs3(fl/fl) lck cre mice showed an increased frequency of γδ+ T cells in different organs and an enhanced secretion of IL-17 by γδ+ T cells in response to infection. Socs3(fl/fl) lck cre γδ+ T cells impaired the control of infection with M. tuberculosis. Thus, SOCS3 expression in either lymphoid or myeloid cells is essential for resistance against M. tuberculosis via discrete mechanisms.
Asunto(s)
Inmunidad Celular , Pulmón/inmunología , Mycobacterium tuberculosis/inmunología , Células Mieloides/metabolismo , Proteínas Supresoras de la Señalización de Citocinas/metabolismo , Linfocitos T/metabolismo , Tuberculosis Pulmonar/inmunología , Animales , Vacuna BCG/uso terapéutico , Receptor gp130 de Citocinas/genética , Receptor gp130 de Citocinas/metabolismo , Citocinas/genética , Citocinas/metabolismo , Células Dendríticas/inmunología , Células Dendríticas/metabolismo , Células Dendríticas/microbiología , Pulmón/microbiología , Pulmón/patología , Macrófagos/inmunología , Macrófagos/metabolismo , Macrófagos/microbiología , Ratones , Ratones Noqueados , Ratones Transgénicos , Mutación , Mycobacterium bovis/crecimiento & desarrollo , Mycobacterium bovis/inmunología , Células Mieloides/inmunología , Células Mieloides/microbiología , Factor de Transcripción STAT3/agonistas , Factor de Transcripción STAT3/genética , Factor de Transcripción STAT3/metabolismo , Transducción de Señal , Organismos Libres de Patógenos Específicos , Proteína 3 Supresora de la Señalización de Citocinas , Proteínas Supresoras de la Señalización de Citocinas/genética , Linfocitos T/inmunología , Linfocitos T/microbiología , Tuberculosis Pulmonar/microbiología , Tuberculosis Pulmonar/patología , Tuberculosis Pulmonar/prevención & controlRESUMEN
In this study, we explored the local cytokine/chemokine profiles in patients with active pulmonary or pleural tuberculosis (TB) using multiplex protein analysis of bronchoalveolar lavage and pleural fluid samples. Despite increased pro-inflammation compared to the uninfected controls; there was no up-regulation of IFN-γ or the T cell chemoattractant CCL5 in the lung of patients with pulmonary TB. Instead, elevated levels of IL-4 and CCL4 were associated with high mycobacteria-specific IgG titres as well as SOCS3 (suppressors of cytokine signaling) mRNA and progression of moderate-to-severe disease. Contrary, IL-4, CCL4 and SOCS3 remained low in patients with extrapulmonary pleural TB, while IFN-γ, CCL5 and SOCS1 were up-regulated. Both SOCS molecules were induced in human macrophages infected with Mycobacterium tuberculosis in vitro. The Th2 immune response signature found in patients with progressive pulmonary TB could result from inappropriate cytokine/chemokine responses and excessive SOCS3 expression that may represent potential targets for clinical TB management.
Asunto(s)
Citocinas/metabolismo , Regulación de la Expresión Génica/inmunología , Proteínas Supresoras de la Señalización de Citocinas/metabolismo , Células Th2/inmunología , Tuberculosis Pulmonar/inmunología , Adolescente , Adulto , Anciano , Células Cultivadas , Progresión de la Enfermedad , Femenino , Infecciones por VIH/inmunología , Infecciones por VIH/metabolismo , Humanos , Leucocitos Mononucleares/metabolismo , Leucocitos Mononucleares/microbiología , Macrófagos/metabolismo , Macrófagos/microbiología , Masculino , Persona de Mediana Edad , Mycobacterium tuberculosis , ARN Mensajero/genética , ARN Mensajero/metabolismo , Proteína 3 Supresora de la Señalización de Citocinas , Proteínas Supresoras de la Señalización de Citocinas/genética , Adulto JovenRESUMEN
Hepatic steatosis is a prominent feature in patients with growth hormone (GH) deficiency. The ubiquitin ligase SOCS2 attenuates hepatic GH signaling by inhibiting the Janus kinase 2 (JAK2)-signal transducer and activator of transcription 5b (STAT5b) axis. Here, we investigated the role of SOCS2 in the development of diet-induced hepatic steatosis and insulin resistance. SOCS2-knockout (SOCS2(-/-)) mice and wild-type littermates were fed for 4 mo with control or high-fat diet, followed by assessment of insulin sensitivity, hepatic lipid content, and expression of inflammatory cytokines. SOCS2(-/-) mice exhibited increased hepatic TG secretion by 77.6% (P<0.001) as compared with wild-type control mice and were protected from high-fat-diet (HFD)-induced hepatic steatosis, showing 49.3% (P<0.01) reduction in liver TG levels compared to HFD-fed wild-type littermates. In contrast, we found that HFD-triggered attenuation of systemic insulin sensitivity was more marked in SOCS2(-/-) mice. Livers from the HFD-fed SOCS2(-/-) mice showed increased NF-κB activity as well as elevated expression of genes for the inflammatory cytokines IFN-γ and IL-6. An inhibitory role of SOCS2 on Toll-like receptor 4 signaling was demonstrated in macrophages obtained from the SOCS2(-/-) and wild-type mice. This study identified SOCS2 as an important regulator of hepatic homeostasis under conditions of high-fat dietary stress.
Asunto(s)
Dieta Alta en Grasa , Hígado Graso/prevención & control , Resistencia a la Insulina/fisiología , Proteínas Supresoras de la Señalización de Citocinas/deficiencia , Proteínas Supresoras de la Señalización de Citocinas/fisiología , Animales , Interferón gamma/metabolismo , Interleucina-6/metabolismo , Metabolismo de los Lípidos , Hígado/metabolismo , Masculino , Ratones , Ratones Noqueados , FN-kappa B/metabolismo , Receptor Toll-Like 4/antagonistas & inhibidores , Triglicéridos/metabolismoRESUMEN
BACKGROUND: Appropriate immune activation of T cells and macrophages is central for the control of Mycobacterium tuberculosis infections. IFN-γ stimulated responses are lowered in tuberculosis (TB), while expression of Suppressor of Cytokine Signaling (SOCS) molecules - 1 and 3 and CD4+CD25+FoxP3+T regulatory cells is increased. Here we investigated the association of these molecules in regard to clinical severity of TB. METHODS: Peripheral blood mononuclear cells (PBMCs) were isolated from patients with pulmonary TB (PTB, n = 33), extra-pulmonary TB (ETB, n = 33) and healthy endemic controls (EC, n = 15). Cases were classified as moderately advanced or far advanced PTB, and less severe or severe disseminated ETB. M. tuberculosis -stimulated IFN-γ, SOCS1, SOCS3 and FoxP3 gene expression and secretion of Th1 and Th2 cytokines was measured. Statistical analysis was performed using Mann-Whitney U, Wilcoxon Rank and Kruskal Wallis non-parametric tests. RESULTS: In un-stimulated PBMCs, IL-6 (p = 0.018) and IL-10 (p = 0.013) secretion levels were increased in PTB while IL-10 was also increased in ETB (p = 0.003), all in comparison with EC. M. tuberculosis-stimulated IL-6 (p = 0.003) was lowered in ETB as compared with EC. SOCS1 mRNA expression in M. tuberculosis stimulated PBMCs levels in moderately advanced PTB (p = 0.022), far advanced (p = 0.014) PTB, and severe ETB (p = 0.009) were raised as compared with EC. On the other hand, SOCS1 mRNA titers were reduced in less severe ETB, in comparison with severe ETB (p = 0.027) and far advanced PTB (p = 0.016). SOCS3 mRNA accumulation was reduced in far advanced PTB (p = 0.007) and FoxP3 mRNA expression was increased in less severe ETB as compared with EC (p = 0.017). CONCLUSIONS: The lowered SOCS1 mRNA levels in patients with less severe extra-pulmonary TB as compared to those with more severe ETB and PTB may lead to elevated IFN-γ pathway gene expression in the latter group. As localized ETB has shown to be associated with more effective Th1 immunity and adaptive responses, this suggests a role for SOCS1 in determining disease outcome in extra-pulmonary TB.
Asunto(s)
Factores de Transcripción Forkhead/genética , Interleucina-6/metabolismo , Mycobacterium tuberculosis , Proteínas Supresoras de la Señalización de Citocinas/genética , Tuberculosis/genética , Tuberculosis/metabolismo , Citocinas/metabolismo , Regulación de la Expresión Génica , Humanos , Leucocitos Mononucleares/inmunología , Leucocitos Mononucleares/metabolismo , Leucocitos Mononucleares/microbiología , Mycobacterium tuberculosis/inmunología , Índice de Severidad de la Enfermedad , Proteína 1 Supresora de la Señalización de Citocinas , Proteína 3 Supresora de la Señalización de Citocinas , Tuberculosis/inmunologíaRESUMEN
Matrix-M™ adjuvant is a key component of several novel vaccine candidates. The Matrix-M adjuvant consists of two distinct fractions of saponins purified from the Quillaja saponaria Molina tree, combined with cholesterol and phospholipids to form 40-nm open cage-like nanoparticles, achieving potent adjuvanticity with a favorable safety profile. Matrix-M induces early activation of innate immune cells at the injection site and in the draining lymph nodes. This translates into improved magnitude and quality of the antibody response to the antigen, broadened epitope recognition, and the induction of a Th1-dominant immune response. Matrix-M-adjuvanted vaccines have a favorable safety profile and are well tolerated in clinical trials. In this review, we discuss the latest findings on the mechanisms of action, efficacy, and safety of Matrix-M adjuvant and other saponin-based adjuvants, with a focus on the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) subunit vaccine candidate NVX-CoV2373 developed to prevent coronavirus disease 2019 (COVID-19).
Asunto(s)
COVID-19 , Saponinas , Vacunas , Humanos , COVID-19/prevención & control , SARS-CoV-2 , Adyuvantes InmunológicosRESUMEN
Tuberculosis (TB) and sarcoidosis are both granulomatous diseases. Here, we compared the immunological microenvironments of granulomas from TB and sarcoidosis patients using in situ sequencing (ISS) transcriptomic analysis and multiplexed immunolabeling of tissue sections. TB lesions consisted of large necrotic and cellular granulomas, whereas "multifocal" granulomas with macrophages or epitheloid cell core and a T-cell rim were observed in sarcoidosis samples. The necrotic core in TB lesions was surrounded by macrophages and encircled by a dense T-cell layer. Within the T-cell layer, compact B-cell aggregates were observed in most TB samples. These B-cell clusters were vascularized and could contain defined B-/T-cell and macrophage-rich areas. The ISS of 40-60 immune transcripts revealed the enriched expression of transcripts involved in homing or migration to lymph nodes, which formed networks at single-cell distances in lymphoid areas of the TB lesions. Instead, myeloid-annotated regions were enriched in CD68, CD14, ITGAM, ITGAX, and CD4 mRNA. CXCL8 and IL1B mRNA were observed in granulocytic areas in which M. tuberculosis was also detected. In line with ISS data indicating tertiary lymphoid structures, immune labeling of TB sections expressed markers of high endothelial venules, follicular dendritic cells, follicular helper T cells, and lymph-node homing receptors on T cells. Neither ISS nor immunolabeling showed evidence of tertiary lymphoid aggregates in sarcoidosis samples. Together, our finding suggests that despite their heterogeneity, the formation of tertiary immune structures is a common feature in granulomas from TB patients.
Asunto(s)
Mycobacterium tuberculosis , Sarcoidosis Pulmonar , Sarcoidosis , Tuberculosis , Humanos , Granuloma , Sarcoidosis Pulmonar/genética , Sarcoidosis Pulmonar/patología , Pulmón/patología , ARN MensajeroRESUMEN
Protection against infection with Mycobacterium tuberculosis demands IFN-γ. SOCS1 has been shown to inhibit responses to IFN-γ and might thereby play a central role in the outcome of infection. We found that M. tuberculosis is a highly efficient stimulator of SOCS1 expression in murine and human macrophages and in tissues from infected mice. Surprisingly, SOCS1 reduced responses to IL-12, resulting in an impaired IFN-γ secretion by macrophages that in turn accounted for a deteriorated intracellular mycobacterial control. Despite SOCS1 expression, mycobacteria-infected macrophages responded to exogenously added IFN-γ. SOCS1 attenuated the expression of the majority of genes modulated by M. tuberculosis infection of macrophages. Using a conditional knockdown strategy in mice, we found that SOCS1 expression by macrophages hampered M. tuberculosis clearance early after infection in vivo in an IFN-γ-dependent manner. On the other hand, at later time points, SOCS1 expression by non-macrophage cells protected the host from infection-induced detrimental inflammation.
Asunto(s)
Interferón gamma/metabolismo , Macrófagos/metabolismo , Mycobacterium tuberculosis/metabolismo , Proteínas Supresoras de la Señalización de Citocinas/metabolismo , Tuberculosis/metabolismo , Animales , Regulación de la Expresión Génica/genética , Regulación de la Expresión Génica/inmunología , Silenciador del Gen , Humanos , Interferón gamma/genética , Interferón gamma/inmunología , Interleucina-12/genética , Interleucina-12/inmunología , Interleucina-12/metabolismo , Macrófagos/inmunología , Macrófagos/microbiología , Ratones , Ratones Noqueados , Ratones Mutantes , Mycobacterium tuberculosis/inmunología , Proteína 1 Supresora de la Señalización de Citocinas , Proteínas Supresoras de la Señalización de Citocinas/genética , Proteínas Supresoras de la Señalización de Citocinas/inmunología , Tuberculosis/genética , Tuberculosis/inmunologíaRESUMEN
Diabetes mellitus (DM) increases the risk of developing tuberculosis (TB), but the mechanisms behind diabetes-TB comorbidity are still undefined. Here, we studied the role of hypoxia-inducible factor-1 (HIF-1), a main regulator of metabolic and inflammatory responses, in the outcome of Mycobacterium tuberculosis infection of bone marrow-derived macrophages (BMM). We observed that M. tuberculosis infection of BMM increased the expression of HIF-1α and HIF-1-regulated genes. Treatment with the hypoxia mimetic deferoxamine (DFO) further increased levels of HIF-1-regulated immune and metabolic molecules and diminished the intracellular bacterial load in BMM and in the lungs of infected mice. The expression of HIF-1-regulated immunometabolic genes was reduced, and the intracellular M. tuberculosis levels were increased in BMM incubated with high-glucose levels or with methylglyoxal (MGO), a reactive carbonyl compound elevated in DM. In line with the in vitro findings, high M. tuberculosis levels and low HIF-1-regulated transcript levels were found in the lungs from hyperglycemic Leprdb/db compared with wild-type mice. The increased intracellular M. tuberculosis growth and the reduced expression of HIF-1-regulated metabolic and inflammatory genes in BMM incubated with MGO or high glucose were reverted by additional treatment with DFO. Hif1a-deficient BMM showed ablated responses of immunometabolic transcripts after mycobacterial infection at normal or high-glucose levels. We propose that HIF-1 may be targeted for the control of M. tuberculosis during DM. IMPORTANCE People living with diabetes who are also infected with M. tuberculosis are more likely to develop tuberculosis disease (TB). Why diabetic patients have an increased risk for developing TB is not well understood. Macrophages, the cell niche for M. tuberculosis, can express microbicidal mechanisms or be permissive to mycobacterial persistence and growth. Here, we showed that high glucose and carbonyl stress, which mediate diabetes pathogenesis, impair the control of intracellular M. tuberculosis in macrophages. Infection with M. tuberculosis stimulated the expression of genes regulated by the transcription factor HIF-1, a major controller of the responses to hypoxia, resulting in macrophage activation. High glucose and carbonyl compounds inhibited HIF-1 responses by macrophages. Mycobacterial control in the presence of glucose or carbonyl stress was restored by DFO, a compound that stabilizes HIF-1. We propose that HIF-1 can be targeted to reduce the risk of developing TB in people with diabetes.
Asunto(s)
Mycobacterium tuberculosis , Tuberculosis , Ratones , Animales , Mycobacterium tuberculosis/fisiología , Factor 1 Inducible por Hipoxia/metabolismo , Piruvaldehído/metabolismo , Deferoxamina/farmacología , Deferoxamina/metabolismo , Óxido de Magnesio/metabolismo , Tuberculosis/microbiología , Macrófagos/microbiología , Hipoxia/metabolismo , Glucosa/metabolismoRESUMEN
Mycobacterium tuberculosis (Mtb) bacilli are the causative agent of tuberculosis (TB), a major killer of mankind. Although it is widely accepted that local interactions between Mtb and the immune system in the tuberculous granuloma determine whether the outcome of infection is controlled or disseminated, these have been poorly studied due to methodological constraints. We have recently used a spatial transcriptomic technique, in situ sequencing (ISS), to define the spatial distribution of immune transcripts in TB mouse lungs. To further contribute to the understanding of the immune microenvironments of Mtb and their local diversity, we here present two complementary automated bacteria-guided analysis pipelines. These position 33 ISS-identified immune transcripts in relation to single bacteria and bacteria clusters. The analysis was applied on new ISS data from lung sections of Mtb-infected C57BL/6 and C3HeB/FeJ mice. In lungs from C57BL/6 mice early and late post infection, transcripts that define inflammatory macrophages were enriched at subcellular distances to bacteria, indicating the activation of infected macrophages. In contrast, expression patterns associated to antigen presentation were enriched in non-infected cells at 12 weeks post infection. T-cell transcripts were evenly distributed in the tissue. In Mtb-infected C3HeB/FeJ mice, transcripts characterizing activated macrophages localized in apposition to small bacteria clusters, but not in organized granulomas. Despite differences in the susceptibility to Mtb, the transcript patterns found around small bacteria clusters of C3HeB/FeJ and C57BL/6 mice were similar. Altogether, the presented tools allow us to characterize in depth the immune cell populations and their activation that interact with Mtb in the infected lung.
Asunto(s)
Mycobacterium tuberculosis , Tuberculosis Ganglionar , Animales , Granuloma/metabolismo , Pulmón , Macrófagos , Ratones , Ratones Endogámicos C57BLRESUMEN
The hypoxia-inducible factors (HIFs) regulate the main transcriptional pathway of response to hypoxia in T cells and are negatively regulated by von Hippel-Lindau factor (VHL). But the role of HIFs in the regulation of CD4 T cell responses during infection with M. tuberculosis isn't well understood. Here we show that mice lacking VHL in T cells (Vhl cKO) are highly susceptible to infection with M. tuberculosis, which is associated with a low accumulation of mycobacteria-specific T cells in the lungs that display reduced proliferation, altered differentiation and enhanced expression of inhibitory receptors. In contrast, HIF-1 deficiency in T cells is redundant for M. tuberculosis control. Vhl cKO mice also show reduced responses to vaccination. Further, VHL promotes proper MYC-activation, cell-growth responses, DNA synthesis, proliferation and survival of CD4 T cells after TCR activation. The VHL-deficient T cell responses are rescued by the loss of HIF-1α, indicating that the increased susceptibility to M. tuberculosis infection and the impaired responses of Vhl-deficient T cells are HIF-1-dependent.
Asunto(s)
Subunidad alfa del Factor 1 Inducible por Hipoxia , Tuberculosis , Proteína Supresora de Tumores del Síndrome de Von Hippel-Lindau , Animales , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Hipoxia , Factor 1 Inducible por Hipoxia , Subunidad alfa del Factor 1 Inducible por Hipoxia/genética , Subunidad alfa del Factor 1 Inducible por Hipoxia/inmunología , Ratones , Linfocitos T/inmunología , Tuberculosis/genética , Tuberculosis/inmunología , Tuberculosis/prevención & control , Proteína Supresora de Tumores del Síndrome de Von Hippel-Lindau/genética , Proteína Supresora de Tumores del Síndrome de Von Hippel-Lindau/inmunologíaRESUMEN
The suppressor of cytokine signaling 3 (SOCS3) is a major regulator of immune responses and inflammation as it negatively regulates cytokine signaling. Here, the role of SOCS3 in thymic T cell formation was studied in Socs3fl/flActin-creER mice (Δsocs3) with a tamoxifen inducible and ubiquitous Socs3 deficiency. Δsocs3 thymi showed a 90% loss of cellularity and altered cortico-medullary organization. Thymocyte differentiation and proliferation was impaired at the early double negative (CD4-CD8-) cell stage and apoptosis was increased during the double positive (CD4+CD8+) cell stage, resulting in the reduction of recent thymic emigrants in peripheral organs. Using bone marrow chimeras, transplanting thymic organoids and using mice deficient of SOCS3 in thymocytes we found that expression in thymic stromal cells rather than in thymocytes was critical for T cell development. We found that SOCS3 in thymic epithelial cells (TECs) binds to the E3 ubiquitin ligase TRIM 21 and that Trim21-/- mice showed increased thymic cellularity. Δsocs3 TECs showed alterations in the expression of genes involved in positive and negative selection and lympho-stromal interactions. SOCS3-dependent signal inhibition of the common gp130 subunit of the IL-6 receptor family was redundant for T cell formation. Together, SOCS3 expression in thymic stroma cells is critical for T cell development and for maintenance of thymus architecture.
Asunto(s)
Diferenciación Celular/inmunología , Células del Estroma/inmunología , Proteína 3 Supresora de la Señalización de Citocinas/inmunología , Linfocitos T/inmunología , Timo/inmunología , Animales , Ratones , Células del Estroma/metabolismo , Proteína 3 Supresora de la Señalización de Citocinas/metabolismo , Timo/metabolismoRESUMEN
Specific T cell responses are central for protection against infection with M. tuberculosis. Here we show that mycobacteria-specific CD4 and CD8 T cells accumulated in the lung but not in the mediastinal lymph node (MLN) at different time points after M. tuberculosis infection or BCG immunization. Proliferating specific T cells were found in the lung after infection and immunization. Pulmonary, but not MLN-derived CD4 and CD8 T cells, from M. tuberculosis-infected mice secreted IFN-γ after stimulation with different mycobacterial peptides. Mycobacteria-specific resident memory CD4 and CD8 T cells (TRM) expressing PD-1 accumulated in the lung after aerosol infection and intratracheal (i.t.) -but not subcutaneous (s.c.)- BCG immunization. Chemical inhibition of recirculation indicated that TRM were generated in the lung after BCG i.t. immunization. In summary, mycobacteria specific-TRM accumulate in the lung during i.t. but not s.c. immunization or M. tuberculosis infection. Collectively our data suggests that priming, accumulation and/or expansion of specific T cells during BCG immunization and M. tuberculosis infection occurs in the lung.
Asunto(s)
Vacuna BCG/administración & dosificación , Linfocitos T CD4-Positivos/efectos de los fármacos , Linfocitos T CD8-positivos/efectos de los fármacos , Pulmón/efectos de los fármacos , Mycobacterium tuberculosis/inmunología , Tuberculosis/inmunología , Administración por Inhalación , Animales , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Inmunización , Inyecciones Subcutáneas , Pulmón/inmunología , Ganglios Linfáticos/efectos de los fármacos , Ganglios Linfáticos/inmunología , Ratones Endogámicos C57BL , Membrana MucosaRESUMEN
Granulomas are the pathological hallmark of tuberculosis (TB) and the niche where bacilli can grow and disseminate or the immunological microenvironment in which host cells interact to prevent bacterial dissemination. Here we show 34 immune transcripts align to the morphology of lung sections from Mycobacterium tuberculosis-infected mice at cellular resolution. Colocalizing transcript networks at <10 µm in C57BL/6 mouse granulomas increase complexity with time after infection. B-cell clusters develop late after infection. Transcripts from activated macrophages are enriched at subcellular distances from M. tuberculosis. Encapsulated C3HeB/FeJ granulomas show necrotic centers with transcripts associated with immunosuppression (Foxp3, Il10), whereas those in the granuloma rims associate with activated T cells and macrophages. We see highly diverse networks with common interactors in similar lesions. Different immune landscapes of M. tuberculosis granulomas depending on the time after infection, the histopathological features of the lesion, and the proximity to bacteria are here defined.
Asunto(s)
Linfocitos B/inmunología , Macrófagos/inmunología , Mycobacterium tuberculosis/inmunología , Tuberculoma/inmunología , Tuberculosis Pulmonar/inmunología , Animales , Linfocitos B/metabolismo , Modelos Animales de Enfermedad , Factores de Transcripción Forkhead/genética , Factores de Transcripción Forkhead/inmunología , Factores de Transcripción Forkhead/metabolismo , Humanos , Interleucina-10/genética , Interleucina-10/inmunología , Interleucina-10/metabolismo , Pulmón/inmunología , Pulmón/microbiología , Pulmón/patología , Macrófagos/metabolismo , Ratones Endogámicos C3H , Ratones Endogámicos C57BL , Mycobacterium tuberculosis/aislamiento & purificación , ARN Mensajero/aislamiento & purificación , Factores de Tiempo , Tuberculoma/microbiología , Tuberculoma/patología , Tuberculosis Pulmonar/microbiología , Tuberculosis Pulmonar/patologíaRESUMEN
CISH gene has been associated with increased susceptibility to human tuberculosis. We found that cish-/- mice had higher M. tuberculosis load in spleens and lungs up to 2.5 weeks after infection but not later compared to controls. Cish mRNA levels were increased in lungs at early and late time points after M. tuberculosis infection. In relation, the titers of inos and tnf mRNA in lungs were reduced early after infection of cish-/- mice. The transfer of cish-/- and control T cells conferred rag1-/- mice similar protection to infection with M. tuberculosis. Macrophages showed increased cish mRNA levels after M. tuberculosis infection in vitro. However, mycobacterial uptake and growth in cish-/- and control macrophages was similar. Thus, we here show that CISH mediates control of M. tuberculosis in mice early after infection via regulation of innate immune mechanisms.