RESUMEN
An infection induces the migration of immune cells called hemocytes to the insect heart, where they aggregate around heart valves called ostia and phagocytose pathogens in areas of high hemolymph flow. Here, we investigated whether the cardiac extracellular matrix proteins, Pericardin (Prc) and Lonely heart (Loh), regulate the infection-induced aggregation of periostial hemocytes in the mosquito, An. gambiae. We discovered that RNAi-based post-transcriptional silencing of Prc or Loh did not affect the resident population of periostial hemocytes in uninfected mosquitoes, but that knocking down these genes decreases the infection-induced migration of hemocytes to the heart. Knocking down Prc or Loh did not affect the proportional distribution of periostial hemocytes along the periostial regions. Moreover, knocking down Prc or Loh did not affect the number of sessile hemocytes outside the periostial regions, suggesting that the role of these proteins is cardiac-specific. Finally, knocking down Prc or Loh did not affect the amount of melanin at the periostial regions, or the intensity of an infection at 24 h after challenge. Overall, we demonstrate that Prc and Loh are positive regulators of the infection-induced migration of hemocytes to the heart of mosquitoes.
Asunto(s)
Anopheles , Hemocitos , Proteínas de Insectos , Animales , Hemocitos/metabolismo , Hemocitos/fisiología , Hemocitos/inmunología , Proteínas de Insectos/metabolismo , Proteínas de Insectos/genética , Anopheles/inmunología , Proteínas de la Matriz Extracelular/metabolismo , Proteínas de la Matriz Extracelular/genética , Movimiento Celular , Interferencia de ARN , Agregación Celular/inmunología , Fagocitosis , Melaninas/metabolismoRESUMEN
Platelet-neutrophil aggregates (PNAs) facilitate neutrophil activation and migration and could underpin the recruitment of neutrophils to the pancreas during type 1 diabetes (T1D) pathogenesis. PNAs, measured by flow cytometry, were significantly elevated in the circulation of autoantibody-positive (Aab+) children and new-onset T1D children, as well as in pre-T1D (at 4 weeks and 10-12 weeks) and T1D-onset NOD mice, compared with relevant controls, and PNAs were characterized by activated P-selectin+ platelets. PNAs were similarly increased in pre-T1D and T1D-onset NOD isolated islets/insulitis, and immunofluorescence staining revealed increased islet-associated neutrophil extracellular trap (NET) products (myeloperoxidase [MPO] and citrullinated histones [CitH3]) in NOD pancreata. In vitro, cell-free histones and NETs induced islet cell damage, which was prevented by the small polyanionic drug methyl cellobiose sulfate (mCBS) that binds to histones and neutralizes their pathological effects. Elevated circulating PNAs could, therefore, act as an innate immune and pathogenic biomarker of T1D autoimmunity. Platelet hyperreactivity within PNAs appears to represent a previously unrecognized hematological abnormality that precedes T1D onset. In summary, PNAs could contribute to the pathogenesis of T1D and potentially function as a pre-T1D diagnostic.
Asunto(s)
Plaquetas/inmunología , Agregación Celular/inmunología , Diabetes Mellitus Tipo 1 , Trampas Extracelulares , Neutrófilos/inmunología , Páncreas , Animales , Autoanticuerpos/sangre , Niño , Diabetes Mellitus Tipo 1/diagnóstico , Diabetes Mellitus Tipo 1/inmunología , Diagnóstico Precoz , Trampas Extracelulares/diagnóstico por imagen , Trampas Extracelulares/inmunología , Femenino , Técnica del Anticuerpo Fluorescente/métodos , Humanos , Masculino , Ratones , Ratones Endogámicos NOD , Activación Neutrófila/inmunología , Selectina-P/metabolismo , Páncreas/inmunología , Páncreas/patologíaRESUMEN
Echinoderms have a large coelomic cavity containing coelomocytes. When the coelomic fluid is removed from the cavity, the cells aggregate immediately. We found that a fraction or an extract of the intestine of the sea cucumber, Apostichopus japonicus, markedly accelerated cellular movement and aggregation on a glass slide, and this effect was clearly inhibited by galactose. We successfully purified the aggregation-promoting factor, a 16 kDa protein, from the intestine. TOF-MS analysis followed by de novo sequencing revealed that the protein is a C-type lectin. RNA-seq data and cDNA cloning demonstrated the factor to be a novel lectin, named AjGBCL, consisting of 158 aa residues in the mature form. Microscopic observation revealed that most of the aggregating cells moved toward aggregates and not to an intestinal fragment, suggesting that AjGBCL is not a chemoattractant but a cellular aggregation-inducing factor that may induce aggregates to release chemoattractant. We report, for the first time, an endogenous molecule that promotes coelomocyte aggregation in echinoderms.
Asunto(s)
Agregación Celular/inmunología , Galectinas/metabolismo , Lectinas Tipo C/metabolismo , Leucocitos/inmunología , Stichopus/inmunología , Animales , Galectinas/aislamiento & purificación , Inmunidad Innata , Intestinos/metabolismo , Lectinas Tipo C/aislamiento & purificación , Leucocitos/metabolismo , Fagocitosis/inmunología , RNA-Seq , Stichopus/citología , Stichopus/metabolismoAsunto(s)
Obstrucción de las Vías Aéreas , Bronquitis , Eosinófilos/inmunología , Trampas Extracelulares , Granulocitos/inmunología , Gripe Humana , Moco , Obstrucción de las Vías Aéreas/inmunología , Obstrucción de las Vías Aéreas/metabolismo , Obstrucción de las Vías Aéreas/patología , Asma/diagnóstico , Asma/inmunología , Bronquitis/complicaciones , Bronquitis/etiología , Bronquitis/inmunología , Bronquitis/patología , Agregación Celular/inmunología , Muerte Celular , Niño , Cromatina/metabolismo , Trampas Extracelulares/inmunología , Trampas Extracelulares/metabolismo , Glicoproteínas/aislamiento & purificación , Humanos , Hipersensibilidad/diagnóstico , Hipersensibilidad/inmunología , Subtipo H1N2 del Virus de la Influenza A/aislamiento & purificación , Gripe Humana/complicaciones , Gripe Humana/diagnóstico , Gripe Humana/inmunología , Gripe Humana/terapia , Lisofosfolipasa/aislamiento & purificación , Masculino , Moco/diagnóstico por imagen , Moco/enzimología , Moco/inmunología , Neutrófilos/inmunología , Factores de RiesgoRESUMEN
Most multicellular organisms have a major body cavity containing vital organs. This cavity is lined by a mucosa-like serosal surface and filled with serous fluid which suspends many immune cells. Injuries affecting the major body cavity are potentially life-threatening. Here we summarize evidence that unique damage detection and repair mechanisms have evolved to ensure immediate and swift repair of injuries at serosal surfaces. Furthermore, thousands of patients undergo surgery within the abdominal and thoracic cavities each day. While these surgeries are potentially lifesaving, some patients will suffer complications due to inappropriate scar formation when wound healing at serosal surfaces defects. These scars called adhesions cause profound challenges for health care systems and patients. Therefore, reviewing the mechanisms of wound repair at serosal surfaces is of clinical importance. Serosal surfaces will be introduced with a short embryological and microanatomical perspective followed by a discussion of the mechanisms of damage recognition and initiation of sterile inflammation at serosal surfaces. Distinct immune cells populations are free floating within the coelomic (peritoneal) cavity and contribute towards damage recognition and initiation of wound repair. We will highlight the emerging role of resident cavity GATA6+ macrophages in repairing serosal injuries and compare serosal (mesothelial) injuries with injuries to the blood vessel walls. This allows to draw some parallels such as the critical role of the mesothelium in regulating fibrin deposition and how peritoneal macrophages can aggregate in a platelet-like fashion in response to sterile injury. Then, we discuss how serosal wound healing can go wrong, causing adhesions. The current pathogenetic understanding of and potential future therapeutic avenues against adhesions are discussed.
Asunto(s)
Macrófagos Peritoneales/inmunología , Peritoneo/inmunología , Membrana Serosa/inmunología , Heridas y Lesiones/inmunología , Animales , Líquido Ascítico/inmunología , Plaquetas/inmunología , Agregación Celular/inmunología , Factor de Transcripción GATA6/análisis , Humanos , Macrófagos Peritoneales/química , Peritoneo/lesiones , Adherencias Tisulares/inmunologíaRESUMEN
Increased accumulation of advanced glycation end products (AGEs) in diabetic skin is closely related to delayed wound healing. Studies have shown that the concentration of AGEs is elevated in the skin tissues and not subcutaneous tissues in refractory diabetic wounds, which suggests there may be a causal relationship between the two. In the present study, in vitro experiments revealed that AGEs activated neutrophils, and the migratory and adhesive functions of neutrophils decreased once AGE levels reached a certain threshold. Different levels of AGE expression differentially affected the function of neutrophils. Messenger RNA (mRNA) sequencing analysis combined with real-time polymerase chain reaction (PCR) showed that poliovirus receptor (PVR/CD155) and CTNND1, which play a role in migration- and adhesion-related signaling pathways, were decreased following AGE stimulation. Consequently, neutrophils cannot effectively stimulate the formation of the inflammatory belt needed to remove necrotic tissues and defend against foreign microorganisms within diabetic chronic wounds. In addition, this phenomenon may be related to the differential accumulation of AGEs in different layers of the skin.
Asunto(s)
Complicaciones de la Diabetes/inmunología , Diabetes Mellitus Experimental/complicaciones , Productos Finales de Glicación Avanzada/metabolismo , Neutrófilos/inmunología , Piel/patología , Animales , Cateninas/metabolismo , Agregación Celular/inmunología , Línea Celular Tumoral , Movimiento Celular/inmunología , Complicaciones de la Diabetes/patología , Diabetes Mellitus Experimental/inducido químicamente , Diabetes Mellitus Experimental/inmunología , Diabetes Mellitus Experimental/patología , Humanos , Masculino , Ratas , Receptores Virales/metabolismo , Piel/citología , Piel/inmunología , Estreptozocina/administración & dosificación , Estreptozocina/toxicidad , Cicatrización de Heridas/inmunología , Catenina deltaRESUMEN
Most multicellular organisms have a major body cavity that harbors immune cells. In primordial species such as purple sea urchins, these cells perform phagocytic functions but are also crucial in repairing injuries. In mammals, the peritoneal cavity contains large numbers of resident GATA6+ macrophages, which may function similarly. However, it is unclear how cavity macrophages suspended in the fluid phase (peritoneal fluid) identify and migrate toward injuries. In this study, we used intravital microscopy to show that cavity macrophages in fluid rapidly form thrombus-like structures in response to injury by means of primordial scavenger receptor cysteine-rich domains. Aggregates of cavity macrophages physically sealed injuries and promoted rapid repair of focal lesions. In iatrogenic surgical situations, these cavity macrophages formed extensive aggregates that promoted the growth of intra-abdominal scar tissue known as peritoneal adhesions.
Asunto(s)
Macrófagos Peritoneales/inmunología , Peritoneo/inmunología , Peritoneo/lesiones , Heridas y Lesiones/inmunología , Animales , Líquido Ascítico/inmunología , Plaquetas/inmunología , Agregación Celular/inmunología , Factor de Transcripción GATA6/análisis , Macrófagos Peritoneales/química , Ratones , Ratones Endogámicos C57BL , Receptores Depuradores de Clase B/inmunología , Trombosis/inmunología , Adherencias Tisulares/inmunologíaRESUMEN
There is a limited number of established ovarian cancer cell lines matching the low-grade serous histotype available for research purposes. Three-dimensional (3D) culture systems provide in vitro models with better tissue-like characteristics than two-dimensional (2D) systems. The goal in the study was to characterize the growth of a given low-grade serous ovarian carcinoma cell line in a 3D culture system conducted in a magnetic field. Moreover, the culture system was evaluated in respect to the assembly of malignant cell aggregates containing lymphocytes. CAISMOV24 cell line alone or mixed with human peripheral blood mononuclear cells (PBMC) were cultured using a commercially available 3D culture system designed for 24 well plates. Resulting cell aggregates revealed the intrinsic capacity of CAISMOV24 cells to assemble structures morphologically defined as papillary, and reflected molecular characteristics usually found in ovarian carcinomas. The contents of lymphocytes into co-cultured cell aggregates were significantly higher (p < 0.05) when NanoShuttle-conjugated PBMC were employed compared with non-conjugated PBMC. Moreover, lymphocyte subsets NK, T-CD4, T-CD8 and T-regulatory were successfully retrieved from co-cultured cell aggregates at 72h. Thus, the culture system allowed CAISMOV24 cell line to develop papillary-like cell aggregates containing lymphocytes.
Asunto(s)
Agregación Celular/inmunología , Técnicas de Cultivo de Célula/métodos , Linfocitos/patología , Neoplasias Ováricas/sangre , Línea Celular Tumoral , Femenino , Humanos , Campos Magnéticos , Clasificación del Tumor , Neoplasias Ováricas/fisiopatología , Microambiente TumoralRESUMEN
BACKGROUND: Chronic inflammation is the driver of liver injury and results in progressive fibrosis and eventual cirrhosis with consequences including both liver failure and liver cancer. We have previously described increased expression of the highly multifunctional glycoprotein CD147 in liver injury. This work describes a novel role of CD147 in liver inflammation and the importance of leukocyte aggregates in determining the extent of liver injury. METHODS: Non-diseased, progressive injury, and cirrhotic liver from humans and mice were examined using a mAb targeting CD147. Inflammatory cell subsets were assessed by multiparameter flow cytometry. RESULTS: In liver injury, we observe abundant, intrahepatic leukocyte clusters defined as ≥5 adjacent CD45+ cells which we have termed "leukocyte aggregates". We have shown that these leukocyte aggregates have a significant effect in determining the extent of liver injury. If CD147 is blocked in vivo, these leukocyte aggregates diminish in size and number, together with a marked significant reduction in liver injury including fibrosis. This is accompanied by no change in overall intrahepatic leukocyte numbers. Further, blocking of aggregation formation occurs prior to an appreciable increase in inflammatory markers or fibrosis. Additionally, there were no observed, "off-target" or unpredicted effects in targeting CD147. CONCLUSION: CD147 mediates leukocyte aggregation which is associated with the development of liver injury. This is not a secondary effect, but a cause of injury as aggregate formation proceeds other markers of injury. Leukocyte aggregation has been previously described in inflammation dating back over many decades. Here we demonstrate that leukocyte aggregates determine the extent of liver injury.
Asunto(s)
Basigina/metabolismo , Leucocitos/inmunología , Hígado/inmunología , Hígado/lesiones , Animales , Basigina/genética , Agregación Celular/inmunología , Hepatocitos/inmunología , Hepatocitos/patología , Humanos , Leucocitos/clasificación , Leucocitos/patología , Hígado/patología , Cirrosis Hepática/genética , Cirrosis Hepática/inmunología , Cirrosis Hepática/patología , Cirrosis Hepática Experimental/genética , Cirrosis Hepática Experimental/inmunología , Cirrosis Hepática Experimental/patología , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Regulación hacia ArribaRESUMEN
BACKGROUND: In a subgroup of patients suffering from progressive multiple sclerosis (MS), which is an inflammation-mediated neurodegenerative disease of the central nervous system (CNS), B cell aggregates were discovered within the meninges. Occurrence of these structures was associated with a more severe disease course and cortical histopathology. We have developed the B cell-dependent MP4-induced experimental autoimmune encephalomyelitis (EAE) as a mouse model to mimic this trait of the human disease. The aim of this study was to determine a potential role of lymphoid tissue inducer (LTi) and TH17 cells in the process of B cell aggregate formation in the MP4 model. METHODS: We performed flow cytometry of cerebellar and splenic tissue of MP4-immunized mice in the acute and chronic stage of the disease to analyze the presence of CD3-CD5-CD4+RORγt+ LTi and CD3+CD5+CD4+RORγt+ TH17 cells. Myelin oligodendrocyte glycoprotein (MOG):35-55-induced EAE was used as B cell-independent control model. We further determined the gene expression profile of B cell aggregates using laser capture microdissection, followed by RNA sequencing. RESULTS: While we were able to detect LTi cells in the embryonic spleen and adult intestine, which served as positive controls, there was no evidence for the existence of such a population in acute or chronic EAE in neither of the two models. Yet, we detected CD3-CD5-CD4-RORγt+ innate lymphoid cells (ILCs) and TH17 cells in the CNS, the latter especially in the chronic stage of MP4-induced EAE. Moreover, we observed a unique gene signature in CNS B cell aggregates compared to draining lymph nodes of MP4-immunized mice and to cerebellum as well as draining lymph nodes of mice with MOG:35-55-induced EAE. CONCLUSION: The absence of LTi cells in the cerebellum suggests that other cells might take over the function as an initiator of lymphoid tissue formation in the CNS. Overall, the development of ectopic lymphoid organs is a complex process based on an interplay between several molecules and signals. Here, we propose some potential candidates, which might be involved in the formation of B cell aggregates in the CNS of MP4-immunized mice.
Asunto(s)
Linfocitos B/inmunología , Modelos Animales de Enfermedad , Encefalomielitis Autoinmune Experimental/inmunología , Tejido Linfoide/inmunología , Esclerosis Múltiple/inmunología , Células Th17/inmunología , Animales , Linfocitos B/patología , Agregación Celular/inmunología , Sistema Nervioso Central/inmunología , Sistema Nervioso Central/patología , Encefalomielitis Autoinmune Experimental/patología , Femenino , Inmunidad Innata/inmunología , Tejido Linfoide/patología , Ratones , Ratones Endogámicos C57BL , Esclerosis Múltiple/patología , Embarazo , Células Th17/patologíaRESUMEN
In gray matter pathology of multiple sclerosis, neurodegeneration associates with a high degree of meningeal inflammatory activity. Importantly, ectopic lymphoid follicles (eLFs) were identified at the inflamed meninges of patients with progressive multiple sclerosis. Besides T lymphocytes, they comprise B cells and might elicit germinal center (GC)-like reactions. GC reactions are controlled by FOXP3+ T-follicular regulatory cells (TFR), but it is unknown if they participate in autoantibody production in eLFs. Receiving human post-mortem material, gathered from autopsies of progressive multiple sclerosis patients, indeed, distinct inflammatory infiltrates enriched with B cells could be detected in perivascular areas and deep sulci. CD35+ cells, parafollicular CD138+ plasma cells, and abundant expression of the homing receptor for GCs, CXCR5, on lymphocytes defined some of them as eLFs. However, they resembled GCs only in varying extent, as T cells did not express PD-1, only few cells were positive for the key transcriptional regulator BCL-6 and ongoing proliferation, whereas a substantial number of T cells expressed high NFATc1 like GC-follicular T cells. Then again, predominant cytoplasmic NFATc1 and an enrichment with CD3+CD27+ memory and CD4+CD69+ tissue-resident cells implied a chronic state, very much in line with PD-1 and BCL-6 downregulation. Intriguingly, FOXP3+ cells were almost absent in the whole brain sections and CD3+FOXP3+ TFRs were never found in the lymphoid aggregates. This also points to less controlled humoral immune responses in those lymphoid aggregates possibly enabling the occurrence of CNS-specific autoantibodies in multiple sclerosis patients.
Asunto(s)
Sistema Nervioso Central , Centro Germinal , Esclerosis Múltiple , Células Plasmáticas , Antígenos CD/inmunología , Agregación Celular/inmunología , Sistema Nervioso Central/inmunología , Sistema Nervioso Central/patología , Femenino , Centro Germinal/inmunología , Centro Germinal/patología , Humanos , Masculino , Esclerosis Múltiple/inmunología , Esclerosis Múltiple/patología , Células Plasmáticas/inmunología , Células Plasmáticas/patología , Linfocitos T Reguladores/inmunología , Linfocitos T Reguladores/patologíaRESUMEN
Erythrocyte Binding Antigen of 175 kDa (EBA-175) has a well-defined role in binding to glycophorin A (GpA) during Plasmodium falciparum invasion of erythrocytes. However, EBA-175 is shed post invasion and a role for this shed protein has not been defined. We show that EBA-175 shed from parasites promotes clustering of RBCs, and EBA-175-dependent clusters occur in parasite culture. Region II of EBA-175 is sufficient for clustering RBCs in a GpA-dependent manner. These clusters are capable of forming under physiological flow conditions and across a range of concentrations. EBA-175-dependent RBC clustering provides daughter merozoites ready access to uninfected RBCs enhancing parasite growth. Clustering provides a general method to protect the invasion machinery from immune recognition and disruption as exemplified by protection from neutralizing antibodies that target AMA-1 and RH5. These findings provide a mechanistic framework for the role of shed proteins in RBC clustering, immune evasion, and malaria.
Asunto(s)
Antígenos de Protozoos/inmunología , Glicoforinas/inmunología , Evasión Inmune , Merozoítos/inmunología , Plasmodium falciparum/inmunología , Proteínas Protozoarias/inmunología , Anticuerpos Neutralizantes/farmacología , Antígenos de Protozoos/genética , Antígenos de Protozoos/metabolismo , Proteínas Portadoras/genética , Proteínas Portadoras/inmunología , Agregación Celular/inmunología , Células Cultivadas , Medios de Cultivo Condicionados/química , Eritrocitos/efectos de los fármacos , Eritrocitos/parasitología , Expresión Génica , Glicoforinas/metabolismo , Humanos , Proteínas de la Membrana/genética , Proteínas de la Membrana/inmunología , Merozoítos/genética , Merozoítos/crecimiento & desarrollo , Plasmodium falciparum/efectos de los fármacos , Plasmodium falciparum/genética , Plasmodium falciparum/crecimiento & desarrollo , Unión Proteica , Proteínas Protozoarias/genética , Proteínas Protozoarias/metabolismoRESUMEN
BACKGROUND & AIMS: GS-9620, an oral agonist of toll-like receptor 7, is in clinical development for the treatment of chronic hepatitis B (CHB). GS-9620 was previously shown to induce prolonged suppression of serum viral DNA and antigens in the chimpanzee and woodchuck models of CHB. Herein, we investigated the immunomodulatory mechanisms underlying these antiviral effects. METHODS: Archived liver biopsies and paired peripheral blood mononuclear cell samples from a previous chimpanzee study were analyzed by RNA sequencing, quantitative reverse transcription PCR, immunohistochemistry (IHC) and in situ hybridization (ISH). RESULTS: GS-9620 treatment of CHB chimpanzees induced an intrahepatic transcriptional profile significantly enriched with genes associated with hepatitis B virus (HBV) clearance in acutely infected chimpanzees. Type I and II interferon, CD8+ T cell and B cell transcriptional signatures were associated with treatment response, together with evidence of hepatocyte death and liver regeneration. IHC and ISH confirmed an increase in intrahepatic CD8+ T cell and B cell numbers during treatment, and revealed that GS-9620 transiently induced aggregates predominantly comprised of CD8+ T cells and B cells in portal regions. There were no follicular dendritic cells or IgG-positive cells in these lymphoid aggregates and very few CD11b+ myeloid cells. There was no change in intrahepatic natural killer cell number during GS-9620 treatment. CONCLUSION: The antiviral response to GS-9620 treatment in CHB chimpanzees was associated with an intrahepatic interferon response and formation of lymphoid aggregates in the liver. Our data indicate these intrahepatic structures are not fully differentiated follicles containing germinal center reactions. However, the temporal correlation between development of these T and B cell aggregates and the antiviral response to treatment suggests they play a role in promoting an effective immune response against HBV. LAY SUMMARY: New therapies to treat chronic hepatitis B (CHB) are urgently needed. In this study we performed a retrospective analysis of liver and blood samples from a chimpanzee model of CHB to help understand how GS-9620, a drug in clinical trials, suppressed hepatitis B virus (HBV). We found that the antiviral response to GS-9620 was associated with accumulation of immune cells in the liver that can either kill cells infected with HBV or can produce antibodies that may prevent HBV from infecting new liver cells. These findings have important implications for how GS-9620 may be used in patients and may also help guide the development of new therapies to treat chronic HBV infection.
Asunto(s)
Antivirales/farmacología , Hepatitis B Crónica/tratamiento farmacológico , Hepatitis B Crónica/inmunología , Pteridinas/farmacología , Receptor Toll-Like 7/agonistas , Animales , Linfocitos B/efectos de los fármacos , Linfocitos B/inmunología , Linfocitos B/patología , Linfocitos T CD8-positivos/efectos de los fármacos , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/patología , Agregación Celular/efectos de los fármacos , Agregación Celular/inmunología , Modelos Animales de Enfermedad , Perfilación de la Expresión Génica , Hepatitis B Crónica/virología , Humanos , Hígado/efectos de los fármacos , Hígado/inmunología , Hígado/patología , Pan troglodytesRESUMEN
Elaboration of tumor necrosis factor (TNF) is a very early event in development of ischemia/reperfusion injury pathophysiology. Therefore, TNF may be a prominent mediator of endothelial cell and vascular wall dysfunction in sickle cell anemia, a hypothesis we addressed using NY1DD, S+SAntilles , and SS-BERK sickle transgenic mice. Transfusion experiments revealed participation of abnormally activated blood monocytes exerting an endothelial activating effect, dependent upon Egr-1 in both vessel wall and blood cells, and upon NFκB(p50) in a blood cell only. Involvement of TNF was identified by beneficial impact from TNF blockers, etanercept and infliximab, with less benefit from an IL-1 blocker, anakinra. In therapeutic studies, etanercept ameliorated multiple disturbances of the murine sickle condition: monocyte activation, blood biomarkers of inflammation, low platelet count and Hb, vascular stasis triggered by hypoxia/reoxygenation (but not if triggered by hemin infusion), tissue production of neuro-inflammatory mediators, endothelial activation (monitored by tissue factor and VCAM-1 expression), histopathologic liver injury, and three surrogate markers of pulmonary hypertension (perivascular inflammatory aggregates, arteriolar muscularization, and right ventricular mean systolic pressure). In aggregate, these studies identify a prominent-and possibly dominant-role for an abnormal monocyte-TNF-endothelial activation axis in the sickle context. Its presence, plus the many benefits of etanercept observed here, argue that pilot testing of TNF blockade should be considered for human sickle cell anemia, a challenging but achievable translational research goal.
Asunto(s)
Anemia de Células Falciformes/metabolismo , Células Endoteliales/metabolismo , Monocitos/metabolismo , Transducción de Señal , Factor de Necrosis Tumoral alfa/metabolismo , Anemia de Células Falciformes/diagnóstico , Anemia de Células Falciformes/tratamiento farmacológico , Anemia de Células Falciformes/genética , Animales , Anticuerpos Monoclonales/farmacología , Biomarcadores , Trasplante de Médula Ósea , Agregación Celular/genética , Agregación Celular/inmunología , Modelos Animales de Enfermedad , Proteína 1 de la Respuesta de Crecimiento Precoz/genética , Proteína 1 de la Respuesta de Crecimiento Precoz/metabolismo , Endotelio Vascular/metabolismo , Etanercept/farmacología , Etanercept/uso terapéutico , Pruebas de Función Cardíaca , Humanos , Mediadores de Inflamación , Leucocitos Mononucleares/efectos de los fármacos , Leucocitos Mononucleares/inmunología , Leucocitos Mononucleares/metabolismo , Ratones , Ratones Noqueados , Ratones Transgénicos , Terapia Molecular Dirigida , Monocitos/efectos de los fármacos , Monocitos/inmunología , FN-kappa B/deficiencia , FN-kappa B/genética , Fenotipo , Inhibidores de Proteínas Quinasas/farmacología , Transducción de Señal/efectos de los fármacos , Tromboplastina/metabolismo , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores , Molécula 1 de Adhesión Celular Vascular/metabolismoRESUMEN
According to the hypothesis presented here, myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) develops over 3 steps: Step 1 is characterized by the aggregation of lymphoid cells in dorsal root ganglia or other nervous structures. The cause of this formation of ectopic lymphoid aggregates may be an acute infection, asymptomatic reactivations of a common neurotropic virus, exposure to a neurotoxin, or physical injury to peripheral nerves. In step 2, Epstein-Barr virus (EBV)-infected lymphocytes or monocytes bring EBV from the circulation to one or several of these lymphoid aggregates, whereupon cell-to-cell transmission of EBV and proliferation of latently EBV-infected lymphocytes lead to the presence of many EBV-infected cells in the lymphoid aggregates. The EBV-infected cells in the aggregates ignite an inflammation in the surrounding nervous tissue. This local inflammation elicits, in turn, a wave of glial cell activation that spreads from the EBV-infected area to parts of the nervous system that are not EBV-infected, disturbing the neuron-glial interaction in both the peripheral - and central nervous system. In step 3, immune cell exhaustion contributes to a consolidation of the pathological processes. There might be a cure: Infusions of autologous EBV-specific T-lymphocytes can perhaps remove the EBV-infected cells from the nervous system.
Asunto(s)
Síndrome de Fatiga Crónica/inmunología , Síndrome de Fatiga Crónica/virología , Herpesvirus Humano 4/inmunología , Linfocitos/inmunología , Linfocitos/virología , Modelos Inmunológicos , Animales , Agregación Celular/inmunología , Medicina Basada en la Evidencia , HumanosRESUMEN
Platelets are subcellular blood elements with a well-established role in haemostasis. Upon activation platelets undergo granule exocytosis, resulting in α-granule P-Selectin being expressed on the cell membrane. This allows binding of activated platelets to P-Selectin glycoprotein ligand 1 (PSGL-1) expressing leukocytes, forming leukocyte-platelet aggregates (LPAs). Whole blood flow cytometry (FCM) has demonstrated that elevated circulating LPAs (especially monocyte LPAs) are linked to atherothrombosis in high risk patients, and that activated platelet binding influences monocytes towards a pro-adhesive and pro-atherogenic phenotype. However, a limitation of conventional FCM is the potential for coincident events to resemble LPAs despite no tethering. Imaging cytometry can be used to characterize LPA formation and distinguish circulating MPAs from coincidental events. Platelets and leukocyte subsets are identified by expression of surface markers (e.g. the lipopolysachharide receptor CD14 on monocytes, glycoprotein Ib CD42b on platelets). In conventional FCM, all events with both leukocyte and platelet characteristics are designated as LPAs. However, by using an 'internal' mask based on the brightfield image and the fluorescent platelet identifier, imaging flow cytometry is able to distinguish leukocytes with tethered platelets (genuine LPAs) from leukocyte with coincidental, untethered platelets nearby. Mechanisms (e.g. adhesion molecules) or consequences (e.g. signal transduction) can then be separately analysed in platelet tethered and untethered leukocytes. Imaging flow cytometry therefore provides a more accurate approach for both enumeration and analysis of LPAs than conventional FCM.
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Plaquetas/inmunología , Comunicación Celular/inmunología , Citometría de Flujo/métodos , Citometría de Imagen/métodos , Monocitos/inmunología , Neutrófilos/inmunología , Biomarcadores/metabolismo , Plaquetas/citología , Agregación Celular/inmunología , Citometría de Flujo/instrumentación , Expresión Génica , Humanos , Citometría de Imagen/instrumentación , Receptores de Lipopolisacáridos/genética , Receptores de Lipopolisacáridos/inmunología , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/inmunología , Monocitos/citología , Neutrófilos/citología , Selectina-P/genética , Selectina-P/inmunología , Activación Plaquetaria , Complejo GPIb-IX de Glicoproteína Plaquetaria/genética , Complejo GPIb-IX de Glicoproteína Plaquetaria/inmunología , Unión ProteicaRESUMEN
B cell aggregates in the central nervous system (CNS) have been associated with rapid disease progression in patients with multiple sclerosis (MS). Here we demonstrate a key role of carcinoembryogenic antigen-related cell adhesion molecule1 (CEACAM1) in B cell aggregate formation in MS patients and a B cell-dependent mouse model of MS. CEACAM1 expression was increased on peripheral blood B cells and CEACAM1(+) B cells were present in brain infiltrates of MS patients. Administration of the anti-CEACAM1 antibody T84.1 was efficient in blocking aggregation of B cells derived from MS patients. Along these lines, application of the monoclonal anti-CEACAM1 antibody mCC1 was able to inhibit CNS B cell aggregate formation and significantly attenuated established MS-like disease in mice in the absence of any adverse effects. CEACAM1 was co-expressed with the regulator molecule T cell immunoglobulin and mucin domain -3 (TIM-3) on B cells, a novel molecule that has recently been described to induce anergy in T cells. Interestingly, elevated coexpression on B cells coincided with an autoreactive T helper cell phenotype in MS patients. Overall, these data identify CEACAM1 as a clinically highly interesting target in MS pathogenesis and open new therapeutic avenues for the treatment of the disease.
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Antígenos CD/genética , Linfocitos B/metabolismo , Moléculas de Adhesión Celular/genética , Sistema Nervioso Central/patología , Esclerosis Múltiple/genética , Animales , Anticuerpos Antiidiotipos/administración & dosificación , Antígenos CD/inmunología , Autoinmunidad/genética , Adhesión Celular/genética , Adhesión Celular/inmunología , Moléculas de Adhesión Celular/antagonistas & inhibidores , Moléculas de Adhesión Celular/inmunología , Agregación Celular/genética , Agregación Celular/inmunología , Sistema Nervioso Central/metabolismo , Modelos Animales de Enfermedad , Regulación de la Expresión Génica/genética , Regulación de la Expresión Génica/inmunología , Humanos , Activación de Linfocitos/genética , Ratones , Esclerosis Múltiple/inmunología , Esclerosis Múltiple/patologíaRESUMEN
Although memory T cells within barrier tissues can persist as permanent residents, at least some exchange with blood. The extent to which this occurs is unclear. Here we show that memory CD4(+) T cells in mouse skin are in equilibrium with the circulation at steady state. These cells are dispersed throughout the inter-follicular regions of the dermis and form clusters with antigen presenting cells around hair follicles. After infection or administration of a contact sensitizing agent, there is a sustained increase in skin CD4(+) T-cell content, which is confined to the clusters, with a concomitant CCL5-dependent increase in CD4(+) T-cell recruitment. Skin CCL5 is derived from CD11b(+) cells and CD8(+) T cells, with the elimination of the latter decreasing CD4(+) T-cell numbers. These results reveal a complex pattern of tissue-retention and equilibration for CD4(+) memory T cells in skin, which is altered by infection and inflammation history.
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Linfocitos T CD4-Positivos/inmunología , Memoria Inmunológica , Adolescente , Adulto , Animales , Células Presentadoras de Antígenos/citología , Células Presentadoras de Antígenos/inmunología , Linfocitos T CD4-Positivos/citología , Linfocitos T CD8-positivos/inmunología , Agregación Celular/inmunología , Movimiento Celular/inmunología , Quimiocina CCL5/metabolismo , Femenino , Folículo Piloso/citología , Folículo Piloso/inmunología , Herpes Simple/inmunología , Herpes Simple/patología , Herpesvirus Humano 1 , Humanos , Interferón gamma/biosíntesis , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos , Persona de Mediana Edad , Piel/citología , Piel/inmunología , Adulto JovenRESUMEN
BACKGROUND & AIMS: The kinase p38(MAPK) and its downstream target MAPKAP kinase (MK) 2 are critical regulators of inflammatory responses towards pathogens. To date, the relevance of MK2 for regulating IL-10 expression and other cytokine responses towards cytomegalovirus (CMV) infection and the impact of this pathway on viral replication in vitro and in vivo is unknown and the subject of this study. METHODS: The effect of MK2, interferon-α receptor (IFNAR)1, tristetraprolin (TTP) and IL-10 on mouse (M)CMV virus titres, cytokine expression, signal transduction, transcript stability, liver enzymes release, immune cell recruitment and aggregation in response to MCMV infection were studied ex vivo in hepatocytes and macrophages, as well as in vivo. RESULTS: MK2 is critical for MCMV-induced production of IL-10, IFN-α2 and 4, IFN-ß, IL-6, and TNF-α but not for IFN-γ. The MCMV-induced IL-10 production requires activation of IFNAR1 and is further regulated by MK2 and TTP-dependent stabilization of IL-10 transcripts. MK2(-/-) mice are able to control acute MCMV replication, despite deregulated cytokine production. This may be related to the observation that MCMV-infected MK2(-/-) mice show enhanced formation of focal intrahepatic lymphocyte infiltrates resembling intrahepatic myeloid cell aggregates of T cell expansion (iMATEs), which were also observed in MCMV-infected IL-10(-/-) mice but are almost absent in MCMV-infected wild-type controls. CONCLUSIONS: The data suggest that MK2 is critical for regulating cytokine responses towards acute MCMV infection, including that of IL-10 via IFNARI-mediated circuits. MCMV stimulates expression of MK2-dependent cytokines, in particular IL-10 and thereby prevents enhanced formation of intrahepatic iMATE-like cellular aggregates.