RESUMEN
The plasma membrane tetraspan molecule MS4A4A is selectively expressed by macrophage-lineage cells, but its function is unknown. Here we report that MS4A4A was restricted to murine and human mononuclear phagocytes and was induced during monocyte-to-macrophage differentiation in the presence of interleukin 4 or dexamethasone. Human MS4A4A was co-expressed with M2/M2-like molecules in subsets of normal tissue-resident macrophages, infiltrating macrophages from inflamed synovium and tumor-associated macrophages. MS4A4A interacted and colocalized with the ß-glucan receptor dectin-1 in lipid rafts. In response to dectin-1 ligands, Ms4a4a-deficient macrophages showed defective signaling and defective production of effector molecules. In experimental models of tumor progression and metastasis, Ms4a4a deficiency in macrophages had no impact on primary tumor growth, but was essential for dectin-1-mediated activation of macrophages and natural killer (NK) cell-mediated metastasis control. Thus, MS4A4A is a tetraspan molecule selectively expressed in macrophages during differentiation and polarization, essential for dectin-1-dependent activation of NK cell-mediated resistance to metastasis.
Asunto(s)
Células Asesinas Naturales/inmunología , Lectinas Tipo C/metabolismo , Macrófagos/inmunología , Proteínas de la Membrana/metabolismo , Metástasis de la Neoplasia/inmunología , Neoplasias/inmunología , Animales , Diferenciación Celular/inmunología , Linaje de la Célula , Dexametasona/farmacología , Humanos , Interleucina-4/metabolismo , Activación de Linfocitos/inmunología , Activación de Macrófagos/inmunología , Macrófagos/citología , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos NOD , Metástasis de la Neoplasia/prevención & control , Neoplasias/patologíaRESUMEN
Sepsis is characterized by a dysregulated inflammatory response to infection. Despite studies in mice, the cellular and molecular basis of human sepsis remains unclear and effective therapies are lacking. Blood monocytes serve as the first line of host defense and are equipped to recognize and respond to infection by triggering an immune-inflammatory response. However, the response of these cells in human sepsis and their contribution to sepsis pathogenesis is poorly understood. To investigate this, we performed a transcriptomic, functional, and mechanistic analysis of blood monocytes from patients during sepsis and after recovery. Our results revealed the functional plasticity of monocytes during human sepsis, wherein they transited from a pro-inflammatory to an immunosuppressive phenotype, while enhancing protective functions like phagocytosis, anti-microbial activity, and tissue remodeling. Mechanistically, hypoxia inducible factor-1α (HIF1α) mediated this functional re-programming of monocytes, revealing a potential mechanism for their therapeutic targeting to regulate human sepsis.
Asunto(s)
Reprogramación Celular/inmunología , Subunidad alfa del Factor 1 Inducible por Hipoxia/inmunología , Huésped Inmunocomprometido , Quinasas Asociadas a Receptores de Interleucina-1/inmunología , Sepsis/inmunología , Inmunidad Adaptativa , Convalecencia , Citocinas/genética , Citocinas/inmunología , Perfilación de la Expresión Génica , Regulación de la Expresión Génica , Humanos , Subunidad alfa del Factor 1 Inducible por Hipoxia/genética , Inmunidad Innata , Quinasas Asociadas a Receptores de Interleucina-1/genética , Monocitos/inmunología , Monocitos/patología , Fagocitosis , Sepsis/genética , Sepsis/patología , Transducción de Señal , Transcriptoma/inmunologíaRESUMEN
Monocytes and macrophages are major components of the tumor microenvironment, but their contributions to human cancer are poorly understood. We used molecular profiling combined with functional assays to investigate the role of these cells in human renal cell carcinoma (RCC). Blood monocytes from RCC patients displayed a tumor-promoting transcriptional profile that supported functions like angiogenesis and invasion. Induction of this protumor phenotype required an interleukin-1 receptor (IL-1R)-dependent mechanism. Indeed, targeting of IL-1-IL-1R axis in a human RCC xenograft model abrogated the protumor phenotype of tumor-associated macrophages (TAMs) and reduced tumor growth in vivo. Supporting this, meta-analysis of gene expression from human RCC tumors showed IL1B expression to correlate with myelomonocytic markers, protumor genes, and tumor staging. Analyzing RCC patient tumors confirmed the protumor phenotype of TAMs. These data provide direct evidence for a tumor-promoting role of monocytes and macrophages in human cancer and indicate IL-1-IL-1R as a possible therapeutic target.
Asunto(s)
Carcinoma de Células Renales/inmunología , Interleucina-1beta/inmunología , Macrófagos/inmunología , Monocitos/inmunología , Receptores de Interleucina-1/inmunología , Animales , Proliferación Celular/genética , Citocinas/biosíntesis , Citocinas/inmunología , Perfilación de la Expresión Génica , Humanos , Inflamación/inmunología , Proteína Antagonista del Receptor de Interleucina 1/farmacología , Interleucina-1beta/antagonistas & inhibidores , Interleucina-1beta/biosíntesis , Interleucina-1beta/genética , Ratones , Ratones Noqueados , Ratones SCID , Factor 88 de Diferenciación Mieloide , Trasplante de Neoplasias , Neovascularización Patológica , Receptores de Interleucina-1/antagonistas & inhibidores , Receptores de Interleucina-1/genética , Factor de Transcripción ReIA/genética , Trasplante Heterólogo , Células Tumorales CultivadasRESUMEN
Studies in the last 20 years have given us a remarkable insight into the functional and phenotypic diversity of macrophages which reflects their integral role in host defence, homeostasis and pathogenesis. Mouse genetics, transcriptomic and epigenetic studies have provided an ontogenic and molecular perspective to the phenotypic diversity of these cells. Recently, metabolic studies have revealed the crucial role of metabolism and metabolites in shaping the phenotype and function of macrophages. Evidence pertaining to this aspect will be reviewed here.
Asunto(s)
Inflamación/metabolismo , Activación de Macrófagos , Macrófagos/inmunología , Animales , Diferenciación Celular , Citocinas/metabolismo , Glucólisis , Homeostasis , Humanos , Inmunidad , Hierro/metabolismo , Metabolismo de los Lípidos , Microbiota , Fosforilación Oxidativa , FenotipoRESUMEN
Natural killer (NK) cells are important for innate immunity in particular through the production of IFN-γ and GM-CSF. Both cytokines are important in restoration of immune function of tolerized leukocytes under inflammatory events. The expression of TLRs in NK cells has been widely studied by analyzing the mRNA of these receptors, rarely seeking their protein expression. We previously showed that murine spleen NK cells express TLR9 intracellularly and respond to CpG oligodeoxynucleotide (CpG-ODN) by producing IFN-γ and GM-CSF. However, to get such production the presence of accessory cytokines (such as IL-15 and IL-18) was required, whereas CpG-ODN or accessory cytokines alone did not induce IFN-γ or GM-CSF. We show here that TLR9 overlaps with the Golgi apparatus in NK cells. Furthermore, CpG-ODN stimulation in the presence of accessory cytokines induces the phosphorylation of c-Jun, STAT3, and IκBα. IFN-γ and GM-CSF production requires NF-κB and STAT3 activation as well as Erk-dependent mechanisms for IFN-γ and p38 signaling for GM-CSF. Using knock-out-mice, we show that UNC93b1 and IL-12 (produced by NK cells themselves) are also necessary for IFN-γ and GM-CSF production. IFN-γ production was found to be MyD88- and TLR9-dependent, whereas GM-CSF was TLR9-independent but dependent on STING (stimulator of interferon genes), a cytosolic adaptor recently described for DNA sensing. Our study thereby allows us to gain insight into the mechanisms of synergy between accessory cytokines and CpG-ODN in NK cells. It also identifies a new and alternative signaling pathway for CpG-ODN in murine NK cells.
Asunto(s)
Factor Estimulante de Colonias de Granulocitos y Macrófagos/biosíntesis , Interferón gamma/biosíntesis , Células Asesinas Naturales/metabolismo , Sistema de Señalización de MAP Quinasas/fisiología , Proteínas de la Membrana/metabolismo , Bazo/metabolismo , Adyuvantes Inmunológicos/farmacología , Animales , Factor Estimulante de Colonias de Granulocitos y Macrófagos/genética , Factor Estimulante de Colonias de Granulocitos y Macrófagos/inmunología , Quinasa I-kappa B/genética , Quinasa I-kappa B/inmunología , Quinasa I-kappa B/metabolismo , Interferón gamma/genética , Interferón gamma/inmunología , Interleucina-15/biosíntesis , Interleucina-15/genética , Interleucina-15/inmunología , Interleucina-18/biosíntesis , Interleucina-18/genética , Interleucina-18/inmunología , Células Asesinas Naturales/citología , Células Asesinas Naturales/inmunología , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Proteínas de la Membrana/genética , Proteínas de la Membrana/inmunología , Ratones , Ratones Noqueados , Factor 88 de Diferenciación Mieloide/genética , Factor 88 de Diferenciación Mieloide/inmunología , Factor 88 de Diferenciación Mieloide/metabolismo , Oligodesoxirribonucleótidos/farmacología , Fosforilación/efectos de los fármacos , Fosforilación/inmunología , Proteínas Proto-Oncogénicas c-jun/genética , Proteínas Proto-Oncogénicas c-jun/inmunología , Proteínas Proto-Oncogénicas c-jun/metabolismo , Factor de Transcripción STAT3/genética , Factor de Transcripción STAT3/inmunología , Factor de Transcripción STAT3/metabolismo , Bazo/citología , Bazo/inmunología , Receptor Toll-Like 9/genética , Receptor Toll-Like 9/inmunología , Receptor Toll-Like 9/metabolismoRESUMEN
Blood monocytes recognize Gram-negative bacteria through the TLR4, which signal via MyD88- and TRIF-dependent pathway to trigger an immune-inflammatory response. However, a dysregulated inflammatory response by these cells often leads to severe pathologies such as sepsis. We investigated the role of CD16 in the regulation of human monocyte response to Gram-negative endotoxin and sepsis. Blood monocytes from sepsis patients demonstrated an upregulation of several TRIF-dependent genes as well as a selective expansion of CD16-expressing (CD16(+)) monocytes. Gene expression and biochemical studies revealed CD16 to regulate the TRIF-dependent TLR4 pathway in monocytes by activating Syk, IFN regulatory factor 3, and STAT1, which resulted in enhanced expression of IFNB, CCL5, and CXCL10. CD16 also upregulated the expression of IL-1R-associated kinase M and IL-1 receptor antagonist, which are negative regulators of the MyD88-dependent pathway. CD16 overexpression or small interfering RNA knockdown in monocytes confirmed the above findings. Interestingly, these results were mirrored in the CD16(+) monocyte subset isolated from sepsis patients, providing an in vivo confirmation to our findings. Collectively, the results from the current study demonstrate CD16 as a key regulator of the TRIF-dependent TLR4 pathway in human monocytes and their CD16-expressing subset, with implications in sepsis.
Asunto(s)
Regulación de la Expresión Génica/inmunología , Monocitos/metabolismo , Receptores de IgG/genética , Sepsis/inmunología , Inmunidad Adaptativa , Proteínas Adaptadoras del Transporte Vesicular/genética , Proteínas Adaptadoras del Transporte Vesicular/inmunología , Adulto , Animales , Endotoxinas/farmacología , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Interferones/genética , Interferones/inmunología , Péptidos y Proteínas de Señalización Intracelular/genética , Péptidos y Proteínas de Señalización Intracelular/inmunología , Ratones , Ratones Endogámicos C57BL , Persona de Mediana Edad , Monocitos/inmunología , Monocitos/patología , Factor 88 de Diferenciación Mieloide/genética , Factor 88 de Diferenciación Mieloide/inmunología , Cultivo Primario de Células , Proteínas Tirosina Quinasas/genética , Proteínas Tirosina Quinasas/inmunología , ARN Interferente Pequeño/genética , Receptores de IgG/inmunología , Factor de Transcripción STAT1/genética , Factor de Transcripción STAT1/inmunología , Sepsis/genética , Sepsis/patología , Transducción de Señal/efectos de los fármacos , Transducción de Señal/inmunología , Quinasa Syk , Receptor Toll-Like 4/genética , Receptor Toll-Like 4/inmunología , TransfecciónRESUMEN
Recently, a relationship between glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and the beta-amyloid precursor protein (betaAPP) in relationship with the pathogenesis of Alzheimer's disease (AD) has been suggested. Therefore, we studied the specific activity of GAPDH in the different animal models of AD: transgenic mice (Tg2576) and rats treated with beta-amyloid, or thiorphan, or lipopolysaccharides (LPS) and interferon gamma (INFgamma). We observed that GAPDH activity was significantly decreased in the brain samples from TG mice. The injection of beta-amyloid, or thiorphan, an inhibitor of neprilysin involved in beta-amyloid catabolism, in rat brains resulted in a pronounced reduction of the enzyme activity. The infusion of LPS and IFNgamma, which can influence the progression of the AD, significantly reduced the enzyme activity.
Asunto(s)
Enfermedad de Alzheimer/metabolismo , Péptidos beta-Amiloides/genética , Gliceraldehído-3-Fosfato Deshidrogenasas/metabolismo , Fragmentos de Péptidos/genética , Telencéfalo/enzimología , Telencéfalo/metabolismo , Enfermedad de Alzheimer/patología , Péptidos beta-Amiloides/administración & dosificación , Péptidos beta-Amiloides/metabolismo , Animales , Modelos Animales de Enfermedad , Inhibidores Enzimáticos/administración & dosificación , Inhibidores Enzimáticos/farmacología , Gliceraldehído-3-Fosfato Deshidrogenasas/análisis , Gliceraldehído-3-Fosfato Deshidrogenasas/genética , Gliceraldehído-3-Fosfato Deshidrogenasas/aislamiento & purificación , Humanos , Bombas de Infusión , Inyecciones Intraventriculares , Interferón gamma/administración & dosificación , Interferón gamma/farmacología , Lipopolisacáridos/administración & dosificación , Lipopolisacáridos/toxicidad , Masculino , Aprendizaje por Laberinto , Ratones , Ratones Transgénicos , Mutación , Neprilisina/antagonistas & inhibidores , Fragmentos de Péptidos/administración & dosificación , Fragmentos de Péptidos/metabolismo , Ratas , Ratas Endogámicas F344 , Tiorfan/administración & dosificación , Tiorfan/farmacologíaRESUMEN
The ability of quaternized polyamines (poly-N-alkyl-4-vinylpyridinium bromides possessing a number, m, of methylene groups in the N-alkyl substituent or a degree of alkylation, beta, and n,n-ionene bromides) to suppress the thermoaggregation of glyceraldehyde-3-phosphate dehydrogenase increased in the order m = 1 < 3 < 5, beta = 95 < 85 < 70 << 45 < 35 < 20 and n = 3 < 6 < 10, which agrees well with the increase, in the same order, in the hydrophobicity of the chains. Complexing suppressed thermoaggregation, but not thermodenaturation of the enzyme, which was even encouraged by the polycations and occurred at room temperature when the most efficient suppressor (with beta = 20) was used. The adverse effect was reduced by the addition of sodium chloride which destroyed the complex and resulted in a noticeable reactivation.
Asunto(s)
Enzimas/química , Gliceraldehído-3-Fosfato Deshidrogenasas/química , Poliaminas/química , Dimerización , Estabilidad de Enzimas , Interacciones Hidrofóbicas e Hidrofílicas , Polielectrolitos , Desnaturalización Proteica , Cloruro de Sodio , TemperaturaRESUMEN
The ability of synthetic polyanions to suppress thermo-aggregation of the oligomeric enzymes (glyceraldehyde-3-phosphate dehydrogenase, lactate dehydrogenase, and aspartate aminotransferase) has been established. The ability of the polyanions to reduce the thermo-aggregation increased in the order poly(methacrylic acid) < poly(acrylic acid) < sodium poly(styrene sulphonate), which agreed well with the increase, in the same order, of the charge density of the chains. The lengthening of the chains, as well as the rise in their relative content, resulted in an increase of the ability to reduce thermo-aggregation, mentioned above. Complete prevention of the enzyme aggregation was achieved when highly charged polyanions of a relatively high degree of polymerization were used in a concentration sufficient to solubilize the protein. Complexing with the polyanions prevented thermo-aggregation of the enzymes, but not their thermo-denaturation. The adverse effect of the complexing polyanions on the catalytic activity was reduced by the addition of a synthetic polycation, which resulted in a significant reactivation (up to 40%) of the enzyme. The possibility of preventing the thermo-aggregation of enzyme molecules and then partly restoring the enzyme activity, appears to be of particular interest when studying the aggregation mechanism of proteins that are prone to form the amyloid structures responsible for the development of neurodegenerative diseases like Alzheimer's disease, bovine spongiform encephalopathy and Huntington disease. This finding can also be considered as an important step in the creation of artificial chaperones.
Asunto(s)
Aniones/química , Enzimas/química , Resinas Acrílicas/química , Aspartato Aminotransferasas/química , Electrólitos/química , Activación Enzimática , Enzimas/metabolismo , Gliceraldehído-3-Fosfato Deshidrogenasas/química , L-Lactato Deshidrogenasa/química , Peso Molecular , Ácidos Polimetacrílicos/química , Poliestirenos/química , Soluciones , Relación Estructura-ActividadRESUMEN
MDSCs are a group of cells with potent immune-suppressive activity. These cells accumulate in many pathologic conditions and play a major role in the regulation of immune responses. The nature of MDSC remains highly debatable. In cancer, most MDSCs are represented by cells with granulocytic phenotype and morphology, G-MDSC. The relationship between G-MDSCs and Neu remains unclear. In this study, we have found that G-MDSCs, from tumor-bearing, and Neu, from tumor-free, mice share a common morphology and phenotype. However, in contrast to Neu, a substantial proportion of G-MDSCs expressed M-CSFR and a CD244 molecule. Neu had significantly higher phagocytic activity, expression of lysosomal proteins, and TNF-α than corresponding G-MDSCs, which had significantly higher activity of arginase, MPO, and ROS. In contrast to G-MDSC, neither rested nor mobilized Neu suppressed T cells. G-MDSC survived 2 days in culture in the presence of GM-CSF and within 24 h, became phenotypic and functionally similar to Neu. Tumor-associated G-MDSC shared most characteristics of splenic G-MDSC, rather then Neu. These data suggest that in cancer, despite morphological and phenotypic similarities, G-MDSCs are functionally distinct from Neu and are comprised of pathologically activated precursors of Neu.
Asunto(s)
Granulocitos/inmunología , Melanoma/inmunología , Células Mieloides/inmunología , Neoplasias Cutáneas/inmunología , Timoma/inmunología , Neoplasias del Timo/inmunología , Animales , Línea Celular Tumoral , Neoplasias del Colon/inmunología , Neoplasias del Colon/patología , Modelos Animales de Enfermedad , Femenino , Granulocitos/citología , Inmunofenotipificación/métodos , Melanoma/patología , Ratones , Ratones Endogámicos C57BL , Células Mieloides/citología , Fagocitosis/inmunología , Neoplasias Cutáneas/patología , Timoma/patología , Neoplasias del Timo/patologíaRESUMEN
The role of myelomonocytic cells like monocytes and macrophages as first line of host defense is well established. Recent understanding of these cells using systems biology, transgenesis and in disease models has brought them to a center stage in orchestrating crucial functions during homeostasis and pathogenesis. Thus, understanding the functional diversity of these cells in health and disease as well as the mechanisms that control these events would be crucial for designing strategies for regulating disease and reinstate homeostasis.
Asunto(s)
Macrófagos/inmunología , Enfermedades Metabólicas/inmunología , Neoplasias/inmunología , Sepsis/inmunología , Animales , Diferenciación Celular , Salud , Homeostasis , Humanos , Inmunidad Innata , Inmunomodulación , Balance Th1 - Th2RESUMEN
An understanding of the solution factors contributing to the rate of aggregation of a protein into amyloid oligomers, to the modulation of the conformational state populated prior to aggregation and to the structure/morphology of the resulting oligomers is one of the goals of present research in this field. We have studied the influence of six different salts on the conversion of the N-terminal domain of Escherichiacoli HypF (HypF-N) into amyloid-like oligomers under conditions of acidic pH. Our results show that salts having different anions (NaCl, NaClO(4), NaI, Na(2)SO(4)) accelerate oligomerization with an efficacy that follows the electroselectivity series of the anions (SO(4)(2-)≥ ClO(4)(-)>I(-)>Cl(-)). By contrast, salts with different cations (NaCl, LiCl, KCl) have similar effects. We also investigated the effect of salts on the structure of the final and initial states of HypF-N aggregation. The electroselectivity series does not apply to the effect of anions on the structure of the oligomers. By contrast, it applies to their effect on the content of secondary structure and on the exposure of hydrophobic clusters of the monomeric precursor state. The results therefore indicate that the binding of anions to the positively charged residues of HypF-N at low pH is the mechanism by which salts modulate the rate of oligomerization and the structure of the monomeric precursor state but not the structure of the resulting oligomers. Overall, the data contribute to rationalize the effect of salts on amyloid-like oligomer formation and to explain the role of charged biological macromolecules in protein aggregation processes.