RESUMO
Cytomegaloviruses (CMVs) have co-evolved with their mammalian hosts for millions of years, leading to remarkable host specificity and high infection prevalence. Macrophages, which already populate barrier tissues in the embryo, are the predominant immune cells at potential CMV entry sites. Here we show that, upon CMV infection, macrophages undergo a morphological, immunophenotypic, and metabolic transformation process with features of stemness, altered migration, enhanced invasiveness, and provision of the cell cycle machinery for viral proliferation. This complex process depends on Wnt signaling and the transcription factor ZEB1. In pulmonary infection, mouse CMV primarily targets and reprograms alveolar macrophages, which alters lung physiology and facilitates primary CMV and secondary bacterial infection by attenuating the inflammatory response. Thus, CMV profoundly perturbs macrophage identity beyond established limits of plasticity and rewires specific differentiation processes, allowing viral spread and impairing innate tissue immunity.
Assuntos
Citomegalovirus/fisiologia , Macrófagos Alveolares/virologia , Animais , Apresentação de Antígeno , Efeito Espectador , Ciclo Celular , Linhagem Celular Transformada , Reprogramação Celular , Citomegalovirus/patogenicidade , Citomegalovirus/ultraestrutura , Infecções por Citomegalovirus/imunologia , Infecções por Citomegalovirus/virologia , Proteínas de Fluorescência Verde/metabolismo , Pulmão/patologia , Macrófagos Alveolares/imunologia , Macrófagos Alveolares/ultraestrutura , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Fenótipo , Células-Tronco/patologia , Replicação Viral/fisiologia , Via de Sinalização WntRESUMO
NLRP3-inflammasome-driven inflammation is involved in the pathogenesis of a variety of diseases. Identification of endogenous inflammasome activators is essential for the development of new anti-inflammatory treatment strategies. Here, we identified that apolipoprotein C3 (ApoC3) activates the NLRP3 inflammasome in human monocytes by inducing an alternative NLRP3 inflammasome via caspase-8 and dimerization of Toll-like receptors 2 and 4. Alternative inflammasome activation in human monocytes is mediated by the Toll-like receptor adapter protein SCIMP. This triggers Lyn/Syk-dependent calcium entry and the production of reactive oxygen species, leading to activation of caspase-8. In humanized mouse models, ApoC3 activated human monocytes in vivo to impede endothelial regeneration and promote kidney injury in an NLRP3- and caspase-8-dependent manner. These data provide new insights into the regulation of the NLRP3 inflammasome and the pathophysiological role of triglyceride-rich lipoproteins containing ApoC3. Targeting ApoC3 might prevent organ damage and provide an anti-inflammatory treatment for vascular and kidney diseases.
Assuntos
Injúria Renal Aguda/imunologia , Apolipoproteína C-III/imunologia , Caspase 8/metabolismo , Nefropatias/imunologia , Monócitos/imunologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/imunologia , Injúria Renal Aguda/patologia , Proteínas Adaptadoras de Transdução de Sinal , Animais , Apolipoproteína C-III/genética , Linhagem Celular , Modelos Animais de Doenças , Células HEK293 , Humanos , Inflamassomos/imunologia , Inflamação/genética , Inflamação/imunologia , Nefropatias/patologia , Proteínas de Membrana , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Camundongos Knockout , Espécies Reativas de Oxigênio/metabolismo , Receptor 2 Toll-Like/metabolismo , Receptor 4 Toll-Like/metabolismoRESUMO
In the version of this article initially published, a reference (23) was cited incorrectly and two references were not included in the second sentence of the first paragraph of the second Results subsection ('Screening for gp61 mimotopes with different functional properties'). The correct citation is as follows: "... we replaced the very stable GFP with a slow fluorescent timer (FT)27,28." Full details on the added references can be found in the correction notice. The errors have been corrected in the print, PDF and HTML versions of the paper.
RESUMO
αß T cell antigen receptors (TCRs) bind complexes of peptide and major histocompatibility complex (pMHC) with low affinity, which poses a considerable challenge for the direct identification of αß T cell cognate peptides. Here we describe a platform for the discovery of MHC class II epitopes based on the screening of engineered reporter cells expressing novel pMHC-TCR (MCR) hybrid molecules carrying cDNA-derived peptides. This technology identifies natural epitopes of CD4+ T cells in an unbiased and efficient manner and allows detailed analysis of TCR cross-reactivity that provides recognition patterns beyond discrete peptides. We determine the cognate peptides of virus- and tumor-specific T cells in mouse disease models and present a proof of concept for human T cells. Furthermore, we use MCR to identify immunogenic tumor neo-antigens and show that vaccination with a peptide naturally recognized by tumor-infiltrating lymphocytes efficiently protects mice from tumor challenge. Thus, the MCR technology holds promise for basic research and clinical applications, allowing the personalized identification of T cell-specific neo-antigens in patients.
Assuntos
Linfócitos T CD4-Positivos/imunologia , Complexo Principal de Histocompatibilidade/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Receptores de Antígenos Quiméricos/imunologia , Especificidade do Receptor de Antígeno de Linfócitos T/imunologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Linfócitos T CD4-Positivos/metabolismo , Linhagem Celular Tumoral , Células Cultivadas , Epitopos de Linfócito T/genética , Epitopos de Linfócito T/imunologia , Epitopos de Linfócito T/metabolismo , Humanos , Complexo Principal de Histocompatibilidade/genética , Camundongos Endogâmicos C57BL , Peptídeos/genética , Peptídeos/imunologia , Peptídeos/metabolismo , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos de Linfócitos T/metabolismo , Receptores de Antígenos Quiméricos/genética , Receptores de Antígenos Quiméricos/metabolismoAssuntos
Influenza Humana , Infecções por Orthomyxoviridae , Humanos , Macrófagos Alveolares , PulmãoRESUMO
Notch2 and B cell antigen receptor (BCR) signaling determine whether transitional B cells become marginal zone B (MZB) or follicular B (FoB) cells in the spleen, but it is unknown how these pathways are related. We generated Taok3-/- mice, lacking the serine/threonine kinase Taok3, and found cell-intrinsic defects in the development of MZB but not FoB cells. Type 1 transitional (T1) B cells required Taok3 to rapidly respond to ligation by the Notch ligand Delta-like 1. BCR ligation by endogenous or exogenous ligands induced the surface expression of the metalloproteinase ADAM10 on T1 B cells in a Taok3-dependent manner. T1 B cells expressing surface ADAM10 were committed to becoming MZB cells in vivo, whereas T1 B cells lacking expression of ADAM10 were not. Thus, during positive selection in the spleen, BCR signaling causes immature T1 B cells to become receptive to Notch ligands via Taok3-mediated surface expression of ADAM10.
Assuntos
Proteína ADAM10/metabolismo , Imunidade Adaptativa , Secretases da Proteína Precursora do Amiloide/metabolismo , Linfócitos B/fisiologia , Diferenciação Celular , Linhagem da Célula , Centro Germinativo/imunologia , Proteínas de Membrana/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteína ADAM10/genética , Secretases da Proteína Precursora do Amiloide/genética , Animais , Células Cultivadas , Seleção Clonal Mediada por Antígeno , Regulação da Expressão Gênica , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas Serina-Treonina Quinases/genética , Receptor Notch2/metabolismo , Receptores de Antígenos de Linfócitos B/metabolismo , Transdução de SinaisRESUMO
CD4+ T helper (Th) cells are fundamental players in immunity. Based on the expression of signature cytokines and transcription factors, several Th subsets have been defined. Th cells are thought to be far more heterogeneous and multifunctional than originally believed, but characterization of the full diversity has been hindered by technical limitations. Here, we employ mass cytometry to analyze the diversity of Th cell responses generated in vitro and in animal disease models, revealing a vast heterogeneity of effector states with distinct cytokine footprints. The diversities of cytokine responses established during primary antigen encounters in Th1- and Th2-cell-polarizing conditions are largely maintained after secondary challenge, regardless of the new inflammatory environment, highlighting many of the identified states as stable Th cell sublineages. We also find that Th17 cells tend to upregulate Th2-cell-associated cytokines upon challenge, indicating a closer developmental connection between Th17 and Th2 cells than previously anticipated.
Assuntos
Citocinas/metabolismo , Células Th1/imunologia , Células Th17/imunologia , Células Th2/imunologia , Animais , Asma/imunologia , Diferenciação Celular/imunologia , Células Cultivadas , Humanos , Ativação Linfocitária/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pyroglyphidae/imunologia , Células Th1/citologia , Células Th17/citologia , Células Th2/citologiaRESUMO
People with diabetes feature a life-risking susceptibility to respiratory viral infection, including influenza and SARS-CoV-2 (ref. 1), whose mechanism remains unknown. In acquired and genetic mouse models of diabetes, induced with an acute pulmonary viral infection, we demonstrate that hyperglycaemia leads to impaired costimulatory molecule expression, antigen transport and T cell priming in distinct lung dendritic cell (DC) subsets, driving a defective antiviral adaptive immune response, delayed viral clearance and enhanced mortality. Mechanistically, hyperglycaemia induces an altered metabolic DC circuitry characterized by increased glucose-to-acetyl-CoA shunting and downstream histone acetylation, leading to global chromatin alterations. These, in turn, drive impaired expression of key DC effectors including central antigen presentation-related genes. Either glucose-lowering treatment or pharmacological modulation of histone acetylation rescues DC function and antiviral immunity. Collectively, we highlight a hyperglycaemia-driven metabolic-immune axis orchestrating DC dysfunction during pulmonary viral infection and identify metabolic checkpoints that may be therapeutically exploited in mitigating exacerbated disease in infected diabetics.
Assuntos
Células Dendríticas , Complicações do Diabetes , Diabetes Mellitus , Suscetibilidade a Doenças , Hiperglicemia , Pulmão , Viroses , Animais , Camundongos , Acetilcoenzima A/metabolismo , Acetilação , Cromatina/genética , Cromatina/metabolismo , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Células Dendríticas/patologia , Complicações do Diabetes/imunologia , Complicações do Diabetes/metabolismo , Diabetes Mellitus/genética , Diabetes Mellitus/imunologia , Diabetes Mellitus/metabolismo , Glucose/metabolismo , Histonas/metabolismo , Hiperglicemia/complicações , Hiperglicemia/imunologia , Hiperglicemia/metabolismo , Pulmão/imunologia , Pulmão/metabolismo , Pulmão/virologia , Linfócitos T/imunologia , Viroses/complicações , Viroses/imunologia , Viroses/mortalidade , Vírus/imunologia , Modelos Animais de Doenças , HumanosRESUMO
The epidermal growth factor receptor ligand Amphiregulin has a well-documented role in the restoration of tissue homeostasis after injury; however, the mechanism by which Amphiregulin contributes to wound repair remains unknown. Here we show that Amphiregulin functioned by releasing bioactive transforming growth factor beta (TGF-ß) from latent complexes via integrin-αV activation. Using acute injury models in two different tissues, we found that by inducing TGF-ß activation on mesenchymal stromal cells (pericytes), Amphiregulin induced their differentiation into myofibroblasts, thereby selectively contributing to the restoration of vascular barrier function within injured tissue. Furthermore, we identified macrophages as a critical source of Amphiregulin, revealing a direct effector mechanism by which these cells contribute to tissue restoration after acute injury. Combined, these observations expose a so far under-appreciated mechanism of how cells of the immune system selectively control the differentiation of tissue progenitor cells during tissue repair and inflammation.
Assuntos
Anfirregulina/metabolismo , Macrófagos/metabolismo , Pericitos/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Animais , Diferenciação Celular/fisiologia , Feminino , Masculino , Células-Tronco Mesenquimais/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Miofibroblastos/metabolismoRESUMO
Gas exchange is the vital function of the lungs. It occurs in the alveoli, where oxygen and carbon dioxide diffuse across the alveolar epithelium and the capillary endothelium surrounding the alveoli, separated only by a fused basement membrane 0.2-0.5 µm in thickness. This tenuous barrier is exposed to dangerous or innocuous particles, toxins, allergens and infectious agents inhaled with the air or carried in the blood. The lung immune system has evolved to ward off pathogens and restrain inflammation-mediated damage to maintain gas exchange. Lung-resident macrophages and dendritic cells are located in close proximity to the epithelial surface of the respiratory system and the capillaries to sample and examine the air-borne and blood-borne material. In communication with alveolar epithelial cells, they set the threshold and the quality of the immune response.
Assuntos
Células Dendríticas/imunologia , Pulmão/imunologia , Macrófagos Alveolares/imunologia , Alvéolos Pulmonares/imunologia , Mucosa Respiratória/imunologia , Animais , Citocinas/imunologia , Células Dendríticas/citologia , Humanos , Pulmão/citologia , Macrófagos Alveolares/citologia , Alvéolos Pulmonares/citologia , Mucosa Respiratória/citologia , Infecções Respiratórias/imunologiaRESUMO
Despite the importance of Th17 cells in autoimmune diseases, it remains unclear how they control other inflammatory cells in autoimmune tissue damage. Using a model of spontaneous autoimmune arthritis, we showed that arthritogenic Th17 cells stimulated fibroblast-like synoviocytes via interleukin-17 (IL-17) to secrete the cytokine GM-CSF and also expanded synovial-resident innate lymphoid cells (ILCs) in inflamed joints. Activated synovial ILCs, which expressed CD25, IL-33Ra, and TLR9, produced abundant GM-CSF upon stimulation by IL-2, IL-33, or CpG DNA. Loss of GM-CSF production by either ILCs or radio-resistant stromal cells prevented Th17 cell-mediated arthritis. GM-CSF production by Th17 cells augmented chronic inflammation but was dispensable for the initiation of arthritis. We showed that GM-CSF-producing ILCs were present in inflamed joints of rheumatoid arthritis patients. Thus, a cellular cascade of autoimmune Th17 cells, ILCs, and stromal cells, via IL-17 and GM-CSF, mediates chronic joint inflammation and can be a target for therapeutic intervention.
Assuntos
Artrite Reumatoide/imunologia , Fator Estimulador de Colônias de Granulócitos e Macrófagos/imunologia , Linfócitos/imunologia , Células Estromais/imunologia , Células Th17/imunologia , Animais , Artrite Reumatoide/metabolismo , Doenças Autoimunes/imunologia , Doenças Autoimunes/metabolismo , Fator Estimulador de Colônias de Granulócitos e Macrófagos/biossíntese , Humanos , Linfócitos/metabolismo , Camundongos , Células Estromais/metabolismo , Membrana Sinovial/imunologia , Membrana Sinovial/metabolismo , Células Th17/metabolismoRESUMO
Tissue-resident macrophages constitute heterogeneous populations with unique functions and distinct gene-expression signatures. While it has been established that they originate mostly from embryonic progenitor cells, the signals that induce a characteristic tissue-specific differentiation program remain unknown. We found that the nuclear receptor PPAR-γ determined the perinatal differentiation and identity of alveolar macrophages (AMs). In contrast, PPAR-γ was dispensable for the development of macrophages located in the peritoneum, liver, brain, heart, kidneys, intestine and fat. Transcriptome analysis of the precursors of AMs from newborn mice showed that PPAR-γ conferred a unique signature, including several transcription factors and genes associated with the differentiation and function of AMs. Expression of PPAR-γ in fetal lung monocytes was dependent on the cytokine GM-CSF. Therefore, GM-CSF has a lung-specific role in the perinatal development of AMs through the induction of PPAR-γ in fetal monocytes.
Assuntos
Diferenciação Celular/imunologia , Fator Estimulador de Colônias de Granulócitos e Macrófagos/metabolismo , Macrófagos Alveolares/citologia , Monócitos/citologia , PPAR gama/biossíntese , Animais , Antígeno CD11c/genética , Antígeno CD11c/imunologia , Diferenciação Celular/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Pulmão/citologia , Pulmão/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , PPAR gama/genéticaRESUMO
Chronic inflammation is a fundamental aspect of metabolic disorders such as obesity, diabetes and cardiovascular disease. Cholesterol crystals are metabolic signals that trigger sterile inflammation in atherosclerosis, presumably by activating inflammasomes for IL-1ß production. We found here that atherogenesis was mediated by IL-1α and we identified fatty acids as potent inducers of IL-1α-driven vascular inflammation. Fatty acids selectively stimulated the release of IL-1α but not of IL-1ß by uncoupling mitochondrial respiration. Fatty acid-induced mitochondrial uncoupling abrogated IL-1ß secretion, which deviated the cholesterol crystal-elicited response toward selective production of IL-1α. Our findings delineate a previously unknown pathway for vascular immunopathology that links the cellular response to metabolic stress with innate inflammation, and suggest that IL-1α, not IL-1ß, should be targeted in patients with cardiovascular disease.
Assuntos
Aterosclerose/metabolismo , Ácidos Graxos/metabolismo , Inflamassomos/metabolismo , Interleucina-1alfa/metabolismo , Mitocôndrias/metabolismo , Vasculite/metabolismo , Animais , Aterosclerose/genética , Aterosclerose/patologia , Sinalização do Cálcio , Gorduras na Dieta/metabolismo , Ácidos Graxos/farmacologia , Feminino , Humanos , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Canais Iônicos/metabolismo , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Camundongos Knockout , Mitocôndrias/efeitos dos fármacos , Proteínas Mitocondriais/metabolismo , Ácido Oleico/farmacologia , Placa Aterosclerótica/metabolismo , Placa Aterosclerótica/patologia , Proteína Desacopladora 2 , Vasculite/patologiaRESUMO
Tissue-resident macrophages (MΦTR ) originate from at least two distinct waves of erythro-myeloid progenitors (EMP) arising in the yolk sac (YS) at E7.5 and E8.5 with the latter going through a liver monocyte intermediate. The relative potential of these precursors in determining development and functional capacity of MΦTR remains unclear. Here, we studied development of alveolar macrophages (AM) after single and competitive transplantation of different precursors from YS, fetal liver, and fetal lung into neonatal Csf2ra-/- mice, which lack endogenous AM. Fetal monocytes, promoted by Myb, outcompeted primitive MΦ (pMΦ) in empty AM niches and preferentially developed to mature AM, which is associated with enhanced mitochondrial respiratory and glycolytic capacity and repression of the transcription factors c-Maf and MafB. Interestingly, AM derived from pMΦ failed to efficiently clear alveolar proteinosis and protect from fatal lung failure following influenza virus infection. Thus, our data demonstrate superior developmental and functional capacity of fetal monocytes over pMΦ in AM development and underlying mechanisms explaining replacement of pMΦ in fetal tissues.
Assuntos
Fígado/embriologia , Pulmão/embriologia , Monócitos/citologia , Receptores de Fator Estimulador das Colônias de Granulócitos e Macrófagos/genética , Saco Vitelino/embriologia , Animais , Células Cultivadas , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Técnicas de Inativação de Genes , Glicólise , Fígado/citologia , Fígado/metabolismo , Pulmão/citologia , Pulmão/metabolismo , Macrófagos Alveolares , Fator de Transcrição MafB/metabolismo , Camundongos , Monócitos/efeitos dos fármacos , Monócitos/metabolismo , Proteínas Proto-Oncogênicas c-maf/metabolismo , Proteínas Proto-Oncogênicas c-myb/farmacologia , Saco Vitelino/citologia , Saco Vitelino/metabolismoRESUMO
The thioredoxin (TRX) system is an important contributor to cellular redox balance and regulates cell growth, apoptosis, gene expression, and antioxidant defense in nearly all living cells. Oxidative stress, the imbalance between reactive oxygen species (ROS) and antioxidants, can lead to cell death and tissue damage, thereby contributing to aging and to the development of several diseases, including cardiovascular and allergic diseases, diabetes, and neurological disorders. Targeting its activity is also considered as a promising strategy in the treatment of cancer. Over the past years, immunologists have established an essential function of TRX for activation, proliferation, and responses in T cells, B cells, and macrophages. Upon activation, immune cells rearrange their redox system and activate the TRX pathway to promote proliferation through sustainment of nucleotide biosynthesis, and to support inflammatory responses in myeloid cells by allowing NF-κB and NLRP3 inflammasome responses. Consequently, targeting the TRX system may therapeutically be exploited to inhibit immune responses in inflammatory conditions. In this review, we summarize recent insights revealing key roles of the TRX pathway in immune cells in health and disease, and lessons learnt for cancer therapy.
Assuntos
Neoplasias , Estresse Oxidativo , Humanos , Antioxidantes/metabolismo , Oxirredução , Tiorredoxinas/metabolismoRESUMO
Tissue-resident macrophages (MTR) have recently emerged as a key rheostat capable of regulating the balance between organ health and disease. In most organs, ontogenetically and functionally distinct macrophage subsets fulfill a plethora of functions specific to their tissue environment. In this review, we summarize recent findings regarding the ontogeny and functions of macrophage populations in different mammalian tissues, describing how these cells regulate tissue homeostasis and how they can contribute to inflammation. Furthermore, we highlight new developments concerning certain general principles of tissue macrophage biology, including the importance of metabolism for understanding macrophage activation states and the influence of intrinsic and extrinsic factors on macrophage metabolic control. We also shed light on certain open questions in the field and how answering these might pave the way for tissue-specific therapeutic approaches.
Assuntos
Ativação de Macrófagos , Macrófagos , Animais , Homeostase , InflamaçãoRESUMO
In the present issue of Immunity, Hoeffel et al. (2015) reconcile a controversy by demonstrating that a distinct wave of yolk-sac-derived erythro-myeloid progenitors (EMPs) differentiate to fetal monocytes in the liver and further to adult macrophages in the majority of tissues.
Assuntos
Envelhecimento/imunologia , Macrófagos/imunologia , Monócitos/imunologia , Células Progenitoras Mieloides/imunologia , Proteínas Proto-Oncogênicas c-myb/imunologia , Animais , Feminino , GravidezRESUMO
Development of dendritic cells (DCs) commences in the bone marrow, from where pre-DCs migrate to peripheral organs to differentiate into mature DCs in situ. However, the factors that regulate organ-specific differentiation to give rise to tissue-specific DC subsets remain unclear. Here we show that the Ras-PI3Kγ-Akt-mTOR signaling axis acted downstream of FLT3L signaling and was required for development of lung CD103(+) DCs and, to a smaller extent, for lung CD11b(+) DCs, but not related DC populations in other non-lymphoid organs. Furthermore, we show that in lymphoid organs such as the spleen, DCs depended on a similar signaling network to respond to FLT3 ligand with overlapping and partially redundant roles for kinases PI3Kγ and PI3Kδ. Thus we identified PI3Kγ as an essential organ-specific regulator of lung DC development and discovered a signaling network regulating tissue-specific DC development mediated by FLT3.