RESUMEN
Clonal hematopoiesis of indeterminate potential (CHIP) arises from aging-associated acquired mutations in hematopoietic progenitors, which display clonal expansion and produce phenotypically altered leukocytes. We associated CHIP-DNMT3A mutations with a higher prevalence of periodontitis and gingival inflammation among 4,946 community-dwelling adults. To model DNMT3A-driven CHIP, we used mice with the heterozygous loss-of-function mutation R878H, equivalent to the human hotspot mutation R882H. Partial transplantation with Dnmt3aR878H/+ bone marrow (BM) cells resulted in clonal expansion of mutant cells into both myeloid and lymphoid lineages and an elevated abundance of osteoclast precursors in the BM and osteoclastogenic macrophages in the periphery. DNMT3A-driven clonal hematopoiesis in recipient mice promoted naturally occurring periodontitis and aggravated experimentally induced periodontitis and arthritis, associated with enhanced osteoclastogenesis, IL-17-dependent inflammation and neutrophil responses, and impaired regulatory T cell immunosuppressive activity. DNMT3A-driven clonal hematopoiesis and, subsequently, periodontitis were suppressed by rapamycin treatment. DNMT3A-driven CHIP represents a treatable state of maladaptive hematopoiesis promoting inflammatory bone loss.
Asunto(s)
Hematopoyesis Clonal , ADN (Citosina-5-)-Metiltransferasas , ADN Metiltransferasa 3A , Periodontitis , Animales , ADN (Citosina-5-)-Metiltransferasas/metabolismo , ADN (Citosina-5-)-Metiltransferasas/genética , Ratones , Hematopoyesis Clonal/genética , Humanos , Periodontitis/genética , Periodontitis/patología , Mutación , Masculino , Femenino , Inflamación/genética , Inflamación/patología , Osteoclastos/metabolismo , Ratones Endogámicos C57BL , Adulto , Interleucina-17/metabolismo , Interleucina-17/genética , Linfocitos T Reguladores/inmunología , Linfocitos T Reguladores/metabolismo , Hematopoyesis/genética , Osteogénesis/genética , Células Madre Hematopoyéticas/metabolismo , Resorción Ósea/genética , Resorción Ósea/patología , Persona de Mediana EdadRESUMEN
Resolution of inflammation is essential for tissue homeostasis and represents a promising approach to inflammatory disorders. Here we found that developmental endothelial locus-1 (DEL-1), a secreted protein that inhibits leukocyte-endothelial adhesion and inflammation initiation, also functions as a non-redundant downstream effector in inflammation clearance. In human and mouse periodontitis, waning of inflammation was correlated with DEL-1 upregulation, whereas resolution of experimental periodontitis failed in DEL-1 deficiency. This concept was mechanistically substantiated in acute monosodium-urate-crystal-induced inflammation, where the pro-resolution function of DEL-1 was attributed to effective apoptotic neutrophil clearance (efferocytosis). DEL-1-mediated efferocytosis induced liver X receptor-dependent macrophage reprogramming to a pro-resolving phenotype and was required for optimal production of at least certain specific pro-resolving mediators. Experiments in transgenic mice with cell-specific overexpression of DEL-1 linked its anti-leukocyte-recruitment action to endothelial cell-derived DEL-1 and its efferocytic/pro-resolving action to macrophage-derived DEL-1. Thus, the compartmentalized expression of DEL-1 facilitates distinct homeostatic functions in an appropriate context that can be harnessed therapeutically.
Asunto(s)
Proteínas Portadoras/metabolismo , Inflamación/inmunología , Macrófagos/fisiología , Neutrófilos/inmunología , Periodontitis/inmunología , Adulto , Animales , Proteínas de Unión al Calcio , Proteínas Portadoras/genética , Moléculas de Adhesión Celular , Reprogramación Celular , Citocinas/metabolismo , Regulación de la Expresión Génica , Humanos , Inflamación/inducido químicamente , Péptidos y Proteínas de Señalización Intercelular , Células K562 , Receptores X del Hígado/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , FagocitosisRESUMEN
In obesity, inflammation of white adipose tissue (AT) is associated with diminished generation of beige adipocytes ('beige adipogenesis'), a thermogenic and energy-dissipating function mediated by beige adipocytes that express the uncoupling protein UCP1. Here we delineated an inflammation-driven inhibitory mechanism of beige adipogenesis in obesity that required direct adhesive interactions between macrophages and adipocytes mediated by the integrin α4 and its counter-receptor VCAM-1, respectively; expression of the latter was upregulated in obesity. This adhesive interaction reciprocally and concomitantly modulated inflammatory activation of macrophages and downregulation of UCP1 expression dependent on the kinase Erk in adipocytes. Genetic or pharmacological inactivation of the integrin α4 in mice resulted in elevated expression of UCP1 and beige adipogenesis of subcutaneous AT in obesity. Our findings, established in both mouse systems and human systems, reveal a self-sustained cycle of inflammation-driven impairment of beige adipogenesis in obesity.
Asunto(s)
Adipocitos Beige , Adipogénesis/inmunología , Tejido Adiposo Blanco/inmunología , Diferenciación Celular/inmunología , Inflamación/inmunología , Macrófagos/inmunología , Obesidad/inmunología , Células 3T3-L1 , Adipocitos/inmunología , Adipocitos/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Animales , Adhesión Celular/inmunología , Dieta Alta en Grasa , Regulación hacia Abajo , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Retroalimentación , Femenino , Técnicas de Silenciamiento del Gen , Humanos , Immunoblotting , Integrina alfa4/genética , Macrófagos/metabolismo , Masculino , Ratones , Persona de Mediana Edad , Monocitos/inmunología , Obesidad/metabolismo , ARN Mensajero/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Grasa Subcutánea , Linfocitos T/inmunología , Proteína Desacopladora 1/genética , Proteína Desacopladora 1/metabolismo , Molécula 1 de Adhesión Celular Vascular/genética , Molécula 1 de Adhesión Celular Vascular/metabolismo , Adulto JovenRESUMEN
Aging is linked to greater susceptibility to chronic inflammatory diseases, several of which, including periodontitis, involve neutrophil-mediated tissue injury. Here we found that aging-associated periodontitis was accompanied by lower expression of Del-1, an endogenous inhibitor of neutrophil adhesion dependent on the integrin LFA-1, and by reciprocal higher expression of interleukin 17 (IL-17). Consistent with that, IL-17 inhibited gingival endothelial cell expression of Del-1, thereby promoting LFA-1-dependent recruitment of neutrophils. Young Del-1-deficient mice developed spontaneous periodontitis that featured excessive neutrophil infiltration and IL-17 expression; disease was prevented in mice doubly deficient in Del-1 and LFA-1 or in Del-1 and the IL-17 receptor. Locally administered Del-1 inhibited IL-17 production, neutrophil accumulation and bone loss. Therefore, Del-1 suppressed LFA-1-dependent recruitment of neutrophils and IL-17-triggered inflammatory pathology and may thus be a promising therapeutic agent for inflammatory diseases.
Asunto(s)
Pérdida de Hueso Alveolar/inmunología , Proteínas Portadoras/metabolismo , Interleucina-17/antagonistas & inhibidores , Interleucina-17/metabolismo , Infiltración Neutrófila/efectos de los fármacos , Periodontitis/metabolismo , Envejecimiento/inmunología , Animales , Proteínas de Unión al Calcio , Proteínas Portadoras/inmunología , Proteínas Portadoras/farmacología , Adhesión Celular/efectos de los fármacos , Moléculas de Adhesión Celular , Células Endoteliales/efectos de los fármacos , Células Endoteliales/inmunología , Femenino , Integrinas/antagonistas & inhibidores , Integrinas/inmunología , Integrinas/metabolismo , Péptidos y Proteínas de Señalización Intercelular , Interleucina-17/inmunología , Antígeno-1 Asociado a Función de Linfocito/inmunología , Antígeno-1 Asociado a Función de Linfocito/metabolismo , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Noqueados , Infiltración Neutrófila/inmunología , Neutrófilos/inmunología , Neutrófilos/metabolismo , Atrofia Periodontal/inmunología , Atrofia Periodontal/metabolismo , Periodontitis/inmunología , Periodontitis/terapia , Receptores de Interleucina-17/deficiencia , Receptores de Interleucina-17/metabolismoRESUMEN
Histamine-induced vascular leakage is a core process of allergic pathologies, including anaphylaxis. Here, we show that glycolysis is integral to histamine-induced endothelial barrier disruption and hyperpermeability. Histamine rapidly enhanced glycolysis in endothelial cells via a pathway that involved histamine receptor 1 and phospholipase C beta signaling. Consistently, partial inhibition of glycolysis with 3-(3-pyridinyl)-1-(4-pyridinyl)-2-propen-1-one (3PO) prevented histamine-induced hyperpermeability in human microvascular endothelial cells, by abolishing the histamine-induced actomyosin contraction, focal adherens junction formation, and endothelial barrier disruption. Pharmacologic blockade of glycolysis with 3PO in mice reduced histamine-induced vascular hyperpermeability, prevented vascular leakage in passive cutaneous anaphylaxis and protected from systemic anaphylaxis. In conclusion, we elucidated the role of glycolysis in histamine-induced disruption of endothelial barrier integrity. Our data thereby point to endothelial glycolysis as a novel therapeutic target for human pathologies related to excessive vascular leakage, such as systemic anaphylaxis.
Asunto(s)
Permeabilidad Capilar/fisiología , Células Endoteliales/efectos de los fármacos , Glucólisis/fisiología , Histamina/farmacología , Uniones Adherentes/efectos de los fármacos , Uniones Adherentes/metabolismo , Anafilaxia/metabolismo , Anafilaxia/patología , Animales , Permeabilidad Capilar/efectos de los fármacos , Células Endoteliales/metabolismo , Endotelio Vascular/efectos de los fármacos , Endotelio Vascular/metabolismo , Ratones , Fosfolipasa C beta/metabolismo , Transducción de Señal/efectos de los fármacosRESUMEN
Inflammation in the central nervous system (CNS) and disruption of its immune privilege are major contributors to the pathogenesis of multiple sclerosis (MS) and of its rodent counterpart, experimental autoimmune encephalomyelitis (EAE). We have previously identified developmental endothelial locus-1 (Del-1) as an endogenous anti-inflammatory factor, which inhibits integrin-dependent leukocyte adhesion. Here we show that Del-1 contributes to the immune privilege status of the CNS. Intriguingly, Del-1 expression decreased in chronic-active MS lesions and in the inflamed CNS in the course of EAE. Del-1-deficiency was associated with increased EAE severity, accompanied by increased demyelination and axonal loss. As compared with control mice, Del-1(-/-) mice displayed enhanced disruption of the blood-brain barrier and increased infiltration of neutrophil granulocytes in the spinal cord in the course of EAE, accompanied by elevated levels of inflammatory cytokines, including interleukin-17 (IL-17). The augmented levels of IL-17 in Del-1-deficiency derived predominantly from infiltrated CD8(+) T cells. Increased EAE severity and neutrophil infiltration because of Del-1-deficiency was reversed in mice lacking both Del-1 and IL-17 receptor, indicating a crucial role for the IL-17/neutrophil inflammatory axis in EAE pathogenesis in Del-1(-/-) mice. Strikingly, systemic administration of Del-1-Fc ameliorated clinical relapse in relapsing-remitting EAE. Therefore, Del-1 is an endogenous homeostatic factor in the CNS protecting from neuroinflammation and demyelination. Our findings provide mechanistic underpinnings for the previous implication of Del-1 as a candidate MS susceptibility gene and suggest that Del-1-centered therapeutic approaches may be beneficial in neuroinflammatory and demyelinating disorders.
Asunto(s)
Axones/metabolismo , Barrera Hematoencefálica/metabolismo , Proteínas Portadoras/metabolismo , Vaina de Mielina/metabolismo , Neuroinmunomodulación/fisiología , Médula Espinal/metabolismo , Animales , Axones/efectos de los fármacos , Axones/patología , Barrera Hematoencefálica/efectos de los fármacos , Barrera Hematoencefálica/patología , Proteínas de Unión al Calcio , Permeabilidad Capilar/efectos de los fármacos , Permeabilidad Capilar/fisiología , Proteínas Portadoras/genética , Moléculas de Adhesión Celular , Encefalomielitis Autoinmune Experimental/tratamiento farmacológico , Encefalomielitis Autoinmune Experimental/metabolismo , Encefalomielitis Autoinmune Experimental/patología , Femenino , Granulocitos/efectos de los fármacos , Granulocitos/metabolismo , Granulocitos/patología , Homeostasis/efectos de los fármacos , Homeostasis/fisiología , Péptidos y Proteínas de Señalización Intercelular , Interleucina-17/metabolismo , Ratones Endogámicos C57BL , Ratones Noqueados , Vaina de Mielina/efectos de los fármacos , Vaina de Mielina/patología , Neuroinmunomodulación/efectos de los fármacos , Neutrófilos/efectos de los fármacos , Neutrófilos/metabolismo , Neutrófilos/patología , Receptores de Interleucina-17/genética , Receptores de Interleucina-17/metabolismo , Índice de Severidad de la Enfermedad , Médula Espinal/efectos de los fármacos , Médula Espinal/patologíaRESUMEN
Formyl peptide receptor 2 (FPR2) is a receptor for formylated peptides and specific pro-resolving mediators, and is involved in various inflammatory processes. Here, we aimed to elucidate the role of FPR2 in dendritic cell (DC) function and autoimmunity-related central nervous system (CNS) inflammation by using the experimental autoimmune encephalomyelitis (EAE) model. EAE induction was accompanied by increased Fpr2 mRNA expression in the spinal cord. FPR2-deficient (Fpr2 KO) mice displayed delayed onset of EAE compared to wild-type (WT) mice, associated with reduced frequencies of Th17 cells in the inflamed spinal cord at the early stage of the disease. However, FPR2 deficiency did not affect EAE severity after the disease reached its peak. FPR2 deficiency in mature DCs resulted in decreased expression of Th17 polarizing cytokines IL6, IL23p19, IL1ß, and thereby diminished the DC-mediated activation of Th17 cell differentiation. LPS-activated FPR2-deficient DCs showed upregulated Nos2 expression and nitric oxide (NO) production, as well as reduced oxygen consumption rate and impaired mitochondrial function, including decreased mitochondrial superoxide levels, lower mitochondrial membrane potential and diminished expression of genes related to the tricarboxylic acid cycle and genes related to the electron transport chain, as compared to WT DCs. Treatment with a NO inhibitor reversed the reduced Th17 cell differentiation in the presence of FPR2-deficient DCs. Together, by regulating DC metabolism, FPR2 enhances the production of DC-derived Th17-polarizing cytokines and hence Th17 cell differentiation in the context of neuroinflammation.
Asunto(s)
Diferenciación Celular , Células Dendríticas , Encefalomielitis Autoinmune Experimental , Ratones Noqueados , Receptores de Formil Péptido , Células Th17 , Animales , Células Dendríticas/inmunología , Células Dendríticas/metabolismo , Receptores de Formil Péptido/genética , Receptores de Formil Péptido/metabolismo , Células Th17/inmunología , Células Th17/metabolismo , Ratones , Encefalomielitis Autoinmune Experimental/inmunología , Encefalomielitis Autoinmune Experimental/metabolismo , Ratones Endogámicos C57BL , Citocinas/metabolismo , Enfermedades Neuroinflamatorias/inmunología , Enfermedades Neuroinflamatorias/metabolismo , Femenino , Médula Espinal/inmunología , Médula Espinal/metabolismoRESUMEN
Aging is associated with increased susceptibility to chronic inflammatory bone loss disorders, such as periodontitis, in large part due to the impaired regenerative potential of aging tissues. DEL-1 exerts osteogenic activity and promotes bone regeneration. However, DEL-1 expression declines with age. Here we show that systemically administered macrolide antibiotics and a non-antibiotic erythromycin derivative, EM-523, restore DEL-1 expression in 18-month-old ("aged") mice while promoting regeneration of bone lost due to naturally occurring age-related periodontitis. These compounds failed to induce bone regeneration in age-matched DEL-1-deficient mice. Consequently, these drugs promoted DEL-1-dependent functions, including alkaline phosphatase activity and osteogenic gene expression in the periodontal tissue while inhibiting osteoclastogenesis, leading to net bone growth. Macrolide-treated aged mice exhibited increased skeletal bone mass, suggesting that this treatment may be pertinent to systemic bone loss disorders. In conclusion, we identified a macrolide-DEL-1 axis that can regenerate bone lost due to aging-related disease.
RESUMEN
Disease amelioration by mesenchymal stem cells (MSCs) has been shown to be closely related to their immunomodulatory functions on the host immune system in many disease models. However, the underlying mechanisms of how these cells affect the immune cells in vivo are not fully understood. In this study, we report findings that a small but significant number of MSCs accumulate in the secondary lymphoid organs and attenuate delayed-type hypersensitivity (DTH) response by inducing apoptotic cell death of surrounding immune cells in the draining lymph node (LN). In the migration study, i.v. infused GFP-MSCs preferentially accumulated at the boundary between the paracortical area and the germinal center in the LNs, in close proximity to various types of immune cells including T, B, and dendritic cells in a dose-dependent manner. As a result, accumulated MSCs markedly attenuated DTH response in proportion to the number of MSCs infused. During the DTH response, the infiltration of T cells in the challenged site was significantly decreased, whereas a number of apoptotic T cells were remarkably increased in the draining LN. Apoptosis was significantly induced in activated T cells (CD3(+) and BrdU(+)), but not in the resting T cells (CD3(+) and BrdU(-)). NO was associated with these apoptotic events. Taken together, we conclude that significant numbers of i.v. infused MSCs preferentially localize in the draining LN, where they induce apoptosis of the activated T cells by producing NO and thus attenuate the DTH response.
Asunto(s)
Apoptosis/inmunología , Quimiotaxis de Leucocito/inmunología , Hipersensibilidad Tardía/inmunología , Inmunomodulación/inmunología , Células Madre Mesenquimatosas/inmunología , Linfocitos T/inmunología , Animales , Efecto Espectador/inmunología , Separación Celular , Citometría de Flujo , Técnica del Anticuerpo Fluorescente , Hipersensibilidad Tardía/metabolismo , Etiquetado Corte-Fin in Situ , Ganglios Linfáticos/citología , Ganglios Linfáticos/inmunología , Ganglios Linfáticos/patología , Células Madre Mesenquimatosas/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Óxido Nítrico/inmunología , Óxido Nítrico/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Linfocitos T/patologíaRESUMEN
Experimental autoimmune encephalomyelitis (EAE) represents the mouse model of multiple sclerosis, a devastating neurological disorder. EAE development and progression involves the infiltration of different immune cells into the brain and spinal cord. However, less is known about a potential role of eosinophil granulocytes for EAE disease pathogenesis. In the present study, we found enhanced eosinophil abundance accompanied by increased concentration of the eosinophil chemoattractant eotaxin-1 in the spinal cord in the course of EAE induced in C57BL/6 mice by immunization with MOG35-55 peptide. However, the absence of eosinophils did not affect neuroinflammation, demyelination and clinical development or severity of EAE, as assessed in ∆dblGATA1 eosinophil-deficient mice. Taken together, despite their enhanced abundance in the inflamed spinal cord during disease progression, eosinophils were dispensable for EAE development.
Asunto(s)
Encefalomielitis Autoinmune Experimental/inmunología , Eosinófilos/inmunología , Esclerosis Múltiple/inmunología , Médula Espinal/patología , Animales , Quimiocina CCL11/metabolismo , Encefalomielitis Autoinmune Experimental/sangre , Encefalomielitis Autoinmune Experimental/diagnóstico , Encefalomielitis Autoinmune Experimental/patología , Eosinófilos/metabolismo , Femenino , Humanos , Ratones , Ratones Transgénicos , Esclerosis Múltiple/sangre , Esclerosis Múltiple/diagnóstico , Esclerosis Múltiple/patología , Glicoproteína Mielina-Oligodendrócito/administración & dosificación , Glicoproteína Mielina-Oligodendrócito/inmunología , Fragmentos de Péptidos/administración & dosificación , Fragmentos de Péptidos/inmunología , Índice de Severidad de la Enfermedad , Médula Espinal/inmunologíaRESUMEN
The secreted protein developmental endothelial locus 1 (DEL-1) regulates inflammatory cell recruitment and protects against inflammatory pathologies in animal models. Here, we investigated DEL-1 in inflammatory arthritis using collagen-induced arthritis (CIA) and collagen Ab-induced arthritis (CAIA) models. In both models, mice with endothelium-specific overexpression of DEL-1 were protected from arthritis relative to WT controls, whereas arthritis was exacerbated in DEL-1-deficient mice. Compared with WT controls, mice with collagen VI promoter-driven overexpression of DEL-1 in mesenchymal cells were protected against CIA but not CAIA, suggesting a role for DEL-1 in the induction of the arthritogenic Ab response. Indeed, DEL-1 was expressed in perivascular stromal cells of the lymph nodes and inhibited Tfh and germinal center B cell responses. Mechanistically, DEL-1 inhibited DC-dependent induction of Tfh cells by targeting the LFA-1 integrin on T cells. Overall, DEL-1 restrained arthritis through a dual mechanism, one acting locally in the joints and associated with the anti-recruitment function of endothelial cell-derived DEL-1; the other mechanism acting systemically in the lymph nodes and associated with the ability of stromal cell-derived DEL-1 to restrain Tfh responses. DEL-1 may therefore be a promising therapeutic for the treatment of inflammatory arthritis.
Asunto(s)
Artritis Experimental/prevención & control , Proteínas de Unión al Calcio/fisiología , Moléculas de Adhesión Celular/fisiología , Activación de Linfocitos , Células T Auxiliares Foliculares/inmunología , Animales , Diferenciación Celular , Femenino , Centro Germinal/inmunología , Antígeno-1 Asociado a Función de Linfocito/fisiología , Masculino , Ratones , Ratones Endogámicos C57BL , Células del Estroma/química , Células T Auxiliares Foliculares/citologíaRESUMEN
Regulatory T cells (Tregs) are vital for the maintenance of immune homeostasis, while their dysfunction constitutes a cardinal feature of autoimmunity. Under steady-state conditions, mitochondrial metabolism is critical for Treg function; however, the metabolic adaptations of Tregs during autoimmunity are ill-defined. Herein, we report that elevated mitochondrial oxidative stress and a robust DNA damage response (DDR) associated with cell death occur in Tregs in individuals with autoimmunity. In an experimental autoimmune encephalitis (EAE) mouse model of autoimmunity, we found a Treg dysfunction recapitulating the features of autoimmune Tregs with a prominent mtROS signature. Scavenging of mtROS in Tregs of EAE mice reversed the DDR and prevented Treg death, while attenuating the Th1 and Th17 autoimmune responses. These findings highlight an unrecognized role of mitochondrial oxidative stress in defining Treg fate during autoimmunity, which may facilitate the design of novel immunotherapies for diseases with disturbed immune tolerance.
Asunto(s)
Autoinmunidad/inmunología , Mitocondrias/inmunología , Linfocitos T Reguladores/inmunología , Animales , Línea Celular , Humanos , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Oxidación-ReducciónRESUMEN
FOXP3+CD4+ regulatory T cells (Tregs) are critical for immune homeostasis and respond to local tissue cues, which control their stability and function. We explored here whether developmental endothelial locus-1 (DEL-1), which, like Tregs, increases during resolution of inflammation, promotes Treg responses. DEL-1 enhanced Treg numbers and function at barrier sites (oral and lung mucosa). The underlying mechanism was dissected using mice lacking DEL-1 or expressing a point mutant thereof, or mice with T cell-specific deletion of the transcription factor RUNX1, identified by RNA sequencing analysis of the DEL-1-induced Treg transcriptome. Specifically, through interaction with αvß3 integrin, DEL-1 promoted induction of RUNX1-dependent FOXP3 expression and conferred stability of FOXP3 expression upon Treg restimulation in the absence of exogenous TGF-ß1. Consistently, DEL-1 enhanced the demethylation of the Treg-specific demethylated region (TSDR) in the mouse Foxp3 gene and the suppressive function of sorted induced Tregs. Similarly, DEL-1 increased RUNX1 and FOXP3 expression in human conventional T cells, promoting their conversion into induced Tregs with increased TSDR demethylation, enhanced stability, and suppressive activity. We thus uncovered a DEL-1/αvß3/RUNX1 axis that promotes Treg responses at barrier sites and offers therapeutic options for modulating inflammatory/autoimmune disorders.
Asunto(s)
Proteínas de Unión al Calcio/inmunología , Moléculas de Adhesión Celular/inmunología , Integrina beta3/inmunología , Transducción de Señal/inmunología , Linfocitos T Reguladores/inmunología , Animales , Proteínas de Unión al Calcio/genética , Moléculas de Adhesión Celular/genética , Subunidad alfa 2 del Factor de Unión al Sitio Principal/genética , Subunidad alfa 2 del Factor de Unión al Sitio Principal/inmunología , Humanos , Inflamación/genética , Inflamación/inmunología , Inflamación/patología , Integrina beta3/genética , Ratones , Ratones Noqueados , Transducción de Señal/genética , Linfocitos T Reguladores/patología , Factor de Crecimiento Transformador beta1/genética , Factor de Crecimiento Transformador beta1/inmunología , Factor de Crecimiento Transformador beta2/genética , Factor de Crecimiento Transformador beta2/inmunologíaRESUMEN
ß2-integrins promote neutrophil recruitment to infected tissues and are crucial for host defense. Neutrophil recruitment is defective in leukocyte adhesion deficiency type-1 (LAD1), a condition caused by mutations in the CD18 (ß2-integrin) gene. Using a model of Citrobacter rodentium (CR)-induced colitis, we show that CD18-/- mice display increased intestinal damage and systemic bacterial burden, compared to littermate controls, ultimately succumbing to infection. This phenotype is not attributed to defective neutrophil recruitment, as it is shared by CXCR2-/- mice that survive CR infection. CR-infected CD18-/- mice feature prominent upregulation of IL-17 and downregulation of IL-22. Exogenous IL-22 administration, but not endogenous IL-17 neutralization, protects CD18-/- mice from lethal colitis. ß2-integrin expression on macrophages is mechanistically linked to Rac1/ROS-mediated induction of noncanonical-NLRP3 (nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3) inflammasome-dependent IL-1ß production, which promotes ILC3-derived IL-22. Therefore, ß2-integrins are required for protective IL-1ß-dependent IL-22 responses in colitis, and the identified mechanism may underlie the association of human LAD1 with colitis.
Asunto(s)
Antígenos CD18/genética , Citrobacter rodentium/patogenicidad , Colitis/genética , Infecciones por Enterobacteriaceae/genética , Interleucinas/genética , Macrófagos/inmunología , Animales , Antígenos CD18/deficiencia , Antígenos CD18/inmunología , Citrobacter rodentium/inmunología , Colitis/inmunología , Colitis/microbiología , Colitis/mortalidad , Infecciones por Enterobacteriaceae/inmunología , Infecciones por Enterobacteriaceae/microbiología , Infecciones por Enterobacteriaceae/mortalidad , Femenino , Regulación de la Expresión Génica/inmunología , Inflamasomas/inmunología , Inflamasomas/metabolismo , Interleucina-17/genética , Interleucina-17/inmunología , Interleucina-1beta/genética , Interleucina-1beta/inmunología , Interleucinas/inmunología , Intestinos/inmunología , Intestinos/microbiología , Intestinos/patología , Macrófagos/microbiología , Macrófagos/patología , Masculino , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/inmunología , Ratones , Ratones Noqueados , Proteína con Dominio Pirina 3 de la Familia NLR/genética , Proteína con Dominio Pirina 3 de la Familia NLR/inmunología , Neuropéptidos/genética , Neuropéptidos/inmunología , Infiltración Neutrófila , Neutrófilos/inmunología , Neutrófilos/microbiología , Neutrófilos/patología , Especies Reactivas de Oxígeno/inmunología , Especies Reactivas de Oxígeno/metabolismo , Análisis de Supervivencia , Proteína de Unión al GTP rac1/genética , Proteína de Unión al GTP rac1/inmunología , Interleucina-22RESUMEN
Platelet-monocyte interactions are strongly implicated in thrombo-inflammatory injury by actively contributing to intravascular inflammation, leukocyte recruitment to inflamed sites, and the amplification of the procoagulant response. Instant blood-mediated inflammatory reaction (IBMIR) represents thrombo-inflammatory injury elicited upon pancreatic islet transplantation (islet-Tx), thereby dramatically affecting transplant survival and function. Developmental endothelial locus-1 (Del-1) is a functionally versatile endothelial cell-derived homeostatic factor with anti-inflammatory properties, but its potential role in IBMIR has not been previously addressed. Here, we establish Del-1 as a novel inhibitor of IBMIR using a whole blood-islet model and a syngeneic murine transplantation model. Indeed, Del-1 pre-treatment of blood before addition of islets diminished coagulation activation and islet damage as assessed by C-peptide release. Consistently, intraportal islet-Tx in transgenic mice with endothelial cell-specific overexpression of Del-1 resulted in a marked decrease of monocytes and platelet-monocyte aggregates in the transplanted tissues, relative to those in wild-type recipients. Mechanistically, Del-1 decreased platelet-monocyte aggregate formation, by specifically blocking the interaction between monocyte Mac-1-integrin and platelet GPIb. Our findings reveal a hitherto unknown role of Del-1 in the regulation of platelet-monocyte interplay and the subsequent heterotypic aggregate formation in the context of IBMIR. Therefore, Del-1 may represent a novel approach to prevent or mitigate the adverse reactions mediated through thrombo-inflammatory pathways in islet-Tx and perhaps other inflammatory disorders involving platelet-leukocyte aggregate formation.
Asunto(s)
Plaquetas/fisiología , Proteínas Portadoras/metabolismo , Inflamación/genética , Trasplante de Islotes Pancreáticos , Islotes Pancreáticos/metabolismo , Monocitos/fisiología , Trombosis/genética , Animales , Coagulación Sanguínea/genética , Proteínas de Unión al Calcio , Proteínas Portadoras/genética , Moléculas de Adhesión Celular , Células Cultivadas , Humanos , Islotes Pancreáticos/patología , Antígeno de Macrófago-1/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Agregación Plaquetaria/genética , Complejo GPIb-IX de Glicoproteína Plaquetaria/metabolismo , Trombosis/inmunologíaRESUMEN
Regulatory T cells (Tregs) are a specialized subpopulation of T cells that control the immune response and thereby maintain immune system homeostasis and tolerance to self-antigens. Many subsets of CD4(+) Tregs have been identified, including Foxp3(+), Tr1, Th3, and Foxp3neg iT(R)35 cells. In this study, we identified a new subset of CD4(+)VEGFR1(high) Tregs that have immunosuppressive capacity. CD4(+)VEGFR1high T cells, which constitute approximately 1.0% of CD4(+) T cells, are hyporesponsive to T-cell antigen receptor stimulation. Surface marker and FoxP3 expression analysis revealed that CD4(+)VEGFR1(high) T cells are distinct from known Tregs. CD4(+)VEGFR1(high) T cells suppressed the proliferation of CD4(+)CD25(-) T cell as efficiently as CD4(+)CD25(high) natural Tregs in a contact-independent manner. Furthermore, adoptive transfer of CD4(+)VEGFR1(+) T cells from wild type to RAG-2-deficient C57BL/6 mice inhibited effector T-cell-mediated inflammatory bowel disease. Thus, we report CD4(+) VEGFR1(high) T cells as a novel subset of Tregs that regulate the inflammatory response in the intestinal tract.
Asunto(s)
Antígenos CD4/metabolismo , Enfermedades Inflamatorias del Intestino/complicaciones , Enfermedades Inflamatorias del Intestino/inmunología , Linfopenia/inmunología , Subgrupos de Linfocitos T/inmunología , Linfocitos T Reguladores/inmunología , Receptor 1 de Factores de Crecimiento Endotelial Vascular/metabolismo , Traslado Adoptivo , Animales , Anticuerpos Monoclonales/farmacología , Apoptosis/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Proteínas de Unión al ADN/metabolismo , Factores de Transcripción Forkhead/metabolismo , Subunidad alfa del Receptor de Interleucina-2/metabolismo , Linfopenia/complicaciones , Ratones Endogámicos C57BL , Ratones Noqueados , Pruebas de Neutralización , Fenotipo , Receptores de Antígenos de Linfocitos T/metabolismo , Solubilidad , Subgrupos de Linfocitos T/efectos de los fármacos , Linfocitos T Reguladores/efectos de los fármacos , Factor A de Crecimiento Endotelial Vascular/metabolismoRESUMEN
Maximum engraftment of transplanted islets is essential for the clinical application of a subcutaneous site. Significant barriers to the current approaches are associated with their low effectiveness, complexity and unproven biosafety. Here, we evaluated and optimized a fibrin-islet composite for effective glycemic control in a subcutaneous site whose environment is highly hypoxic due to low vascularization potential. In the setting of xenogeneic porcine islet transplantation into the subcutaneous space of a diabetic mouse, the in vivo islet functions were greatly affected by the concentrations of fibrinogen and thrombin. The optimized hydrogel-type fibrin remarkably reduced the marginal islet mass to approximately one tenth that of islets without fibrin. This marginal islet mass was comparable to that in the setting of the subcapsular space of the kidney, which is a highly vascularized organ. Highly vascularized structures were generated inside and on the outer surface of the grafts. A hydrogel-type fibrin-islet composite established early diabetic control within an average of 3.4days after the transplantation. In the mechanistic studies, fibrin promoted local angiogenesis, enhanced islet viability and prevented fragmentation of islets into single cells. In conclusion, in situ application of hydrogel-type fibrin-islet composite may be a promising modality in the clinical success of subcutaneous islet transplantation.
Asunto(s)
Fibrina/administración & dosificación , Hidrogeles/administración & dosificación , Trasplante de Islotes Pancreáticos , Trasplante Heterólogo , Animales , Glucemia/análisis , Diabetes Mellitus/sangre , Diabetes Mellitus/cirugía , Ratones , Ratones Endogámicos NOD , Ratones SCID , PorcinosRESUMEN
BACKGROUND: Memory T cells specific for donor antigens are currently recognized as a significant barrier for maintaining a successful transplant. Furthermore, it has been shown that commonly used immunosuppressive drugs do not alleviate this memory response. Here, we report that rapamycin allows significant proliferation of memory T cells and bortezomib can abrogate the proliferation of rapamycin-resistant memory T cells when preserving the survival of regulatory T cells. METHODS: Peripheral blood mononuclear cells freshly isolated from non-human primates were stimulated with anti-CD3/CD28 antibodies, and inhibitory and apoptotic effects of rapamycin and bortezomib on memory T-cell proliferation were investigated. The CD95 marker in CD3+ T cells was used for the separate enrichment of memory T cells and naïve T cells. RESULTS: Rapamycin at the level even higher than therapeutic concentration could not suppress the proliferation of a significant proportion of memory T cells. However, the combined administration of bortezomib and rapamycin abrogated the proliferation of rapamycin-resistant memory T cells. Furthermore, bortezomib preserved the survival of preexisting CD4+ FoxP3+ regulatory T cells, while inducing apoptosis of CD4+ FoxP3- conventional T cells. The combined administration of low doses of rapamycin and bortezomib also exerted an additive effect on suppressing T-cell proliferation. Cytokine analysis demonstrated that bortezomib could not only suppress rapamycin-permissive interleukin (IL)-6 production, but also production of interferon (IFN)-gamma, IL-4, and IL-10. CONCLUSIONS: This article provides in vitro data from which immunosuppressive regimens for the effective control of memory T cells in non-human preclinical experiments and in clinical trials are selected.