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1.
Cell ; 187(17): 4637-4655.e26, 2024 Aug 22.
Artículo en Inglés | MEDLINE | ID: mdl-39043180

RESUMEN

The medical burden of stroke extends beyond the brain injury itself and is largely determined by chronic comorbidities that develop secondarily. We hypothesized that these comorbidities might share a common immunological cause, yet chronic effects post-stroke on systemic immunity are underexplored. Here, we identify myeloid innate immune memory as a cause of remote organ dysfunction after stroke. Single-cell sequencing revealed persistent pro-inflammatory changes in monocytes/macrophages in multiple organs up to 3 months after brain injury, notably in the heart, leading to cardiac fibrosis and dysfunction in both mice and stroke patients. IL-1ß was identified as a key driver of epigenetic changes in innate immune memory. These changes could be transplanted to naive mice, inducing cardiac dysfunction. By neutralizing post-stroke IL-1ß or blocking pro-inflammatory monocyte trafficking with a CCR2/5 inhibitor, we prevented post-stroke cardiac dysfunction. Such immune-targeted therapies could potentially prevent various IL-1ß-mediated comorbidities, offering a framework for secondary prevention immunotherapy.


Asunto(s)
Lesiones Encefálicas , Inmunidad Innata , Memoria Inmunológica , Inflamación , Interleucina-1beta , Ratones Endogámicos C57BL , Monocitos , Animales , Ratones , Interleucina-1beta/metabolismo , Lesiones Encefálicas/inmunología , Humanos , Masculino , Monocitos/metabolismo , Monocitos/inmunología , Inflamación/inmunología , Macrófagos/inmunología , Macrófagos/metabolismo , Accidente Cerebrovascular/complicaciones , Accidente Cerebrovascular/inmunología , Cardiopatías/inmunología , Femenino , Receptores CCR2/metabolismo , Fibrosis , Epigénesis Genética , Inmunidad Entrenada
2.
Cell ; 183(5): 1282-1297.e18, 2020 11 25.
Artículo en Inglés | MEDLINE | ID: mdl-33098771

RESUMEN

Classically considered short-lived and purely defensive leukocytes, neutrophils are unique in their fast and moldable response to stimulation. This plastic behavior may underlie variable and even antagonistic functions during inflammation or cancer, yet the full spectrum of neutrophil properties as they enter healthy tissues remains unexplored. Using a new model to track neutrophil fates, we found short but variable lifetimes across multiple tissues. Through analysis of the receptor, transcriptional, and chromatin accessibility landscapes, we identify varying neutrophil states and assign non-canonical functions, including vascular repair and hematopoietic homeostasis. Accordingly, depletion of neutrophils compromised angiogenesis during early age, genotoxic injury, and viral infection, and impaired hematopoietic recovery after irradiation. Neutrophils acquired these properties in target tissues, a process that, in the lungs, occurred in CXCL12-rich areas and relied on CXCR4. Our results reveal that tissues co-opt neutrophils en route for elimination to induce programs that support their physiological demands.


Asunto(s)
Linaje de la Célula , Neutrófilos/metabolismo , Especificidad de Órganos , Animales , Cromatina/metabolismo , Femenino , Hematopoyesis , Intestinos/irrigación sanguínea , Pulmón/irrigación sanguínea , Masculino , Ratones Endogámicos C57BL , Neovascularización Fisiológica , Miembro 1 del Grupo A de la Subfamilia 4 de Receptores Nucleares/metabolismo , Receptores CXCR4/metabolismo , Análisis de la Célula Individual , Transcripción Genética , Transcriptoma/genética
3.
Immunity ; 56(10): 2325-2341.e15, 2023 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-37652021

RESUMEN

Maladaptive, non-resolving inflammation contributes to chronic inflammatory diseases such as atherosclerosis. Because macrophages remove necrotic cells, defective macrophage programs can promote chronic inflammation with persistent tissue injury. Here, we investigated the mechanisms sustaining vascular macrophages. Intravital imaging revealed a spatiotemporal macrophage niche across vascular beds alongside mural cells (MCs)-pericytes and smooth muscle cells. Single-cell transcriptomics, co-culture, and genetic deletion experiments revealed MC-derived expression of the chemokines CCL2 and MIF, which actively preserved macrophage survival and their homeostatic functions. In atherosclerosis, this positioned macrophages in viable plaque areas, away from the necrotic core, and maintained a homeostatic macrophage phenotype. Disruption of this MC-macrophage unit via MC-specific deletion of these chemokines triggered detrimental macrophage relocalizing, exacerbated plaque necrosis, inflammation, and atheroprogression. In line, CCL2 inhibition at advanced stages of atherosclerosis showed detrimental effects. This work presents a MC-driven safeguard toward maintaining the homeostatic vascular macrophage niche.


Asunto(s)
Aterosclerosis , Placa Aterosclerótica , Humanos , Macrófagos/metabolismo , Aterosclerosis/metabolismo , Placa Aterosclerótica/metabolismo , Quimiocinas/metabolismo , Inflamación/metabolismo , Necrosis/metabolismo
4.
Immunity ; 55(12): 2285-2299.e7, 2022 12 13.
Artículo en Inglés | MEDLINE | ID: mdl-36272416

RESUMEN

Intravascular neutrophils and platelets collaborate in maintaining host integrity, but their interaction can also trigger thrombotic complications. We report here that cooperation between neutrophil and platelet lineages extends to the earliest stages of platelet formation by megakaryocytes in the bone marrow. Using intravital microscopy, we show that neutrophils "plucked" intravascular megakaryocyte extensions, termed proplatelets, to control platelet production. Following CXCR4-CXCL12-dependent migration towards perisinusoidal megakaryocytes, plucking neutrophils actively pulled on proplatelets and triggered myosin light chain and extracellular-signal-regulated kinase activation through reactive oxygen species. By these mechanisms, neutrophils accelerate proplatelet growth and facilitate continuous release of platelets in steady state. Following myocardial infarction, plucking neutrophils drove excessive release of young, reticulated platelets and boosted the risk of recurrent ischemia. Ablation of neutrophil plucking normalized thrombopoiesis and reduced recurrent thrombosis after myocardial infarction and thrombus burden in venous thrombosis. We establish neutrophil plucking as a target to reduce thromboischemic events.


Asunto(s)
Enfermedades Cardiovasculares , Infarto del Miocardio , Trombosis , Humanos , Megacariocitos , Trombopoyesis , Neutrófilos , Plaquetas/fisiología
5.
Nat Immunol ; 24(6): 887-888, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-37188943
6.
Nature ; 633(8029): 433-441, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39112714

RESUMEN

The risk of early recurrent events after stroke remains high despite currently established secondary prevention strategies1. Risk is particularly high in patients with atherosclerosis, with more than 10% of patients experiencing early recurrent events1,2. However, despite the enormous medical burden of this clinical phenomenon, the underlying mechanisms leading to increased vascular risk and recurrent stroke are largely unknown. Here, using a novel mouse model of stroke-induced recurrent ischaemia, we show that stroke leads to activation of the AIM2 inflammasome in vulnerable atherosclerotic plaques via an increase of circulating cell-free DNA. Enhanced plaque inflammation post-stroke results in plaque destabilization and atherothrombosis, finally leading to arterioarterial embolism and recurrent stroke within days after the index stroke. We confirm key steps of plaque destabilization also after experimental myocardial infarction and in carotid artery plaque samples from patients with acute stroke. Rapid neutrophil NETosis was identified as the main source of cell-free DNA after stroke and NET-DNA as the causative agent leading to AIM2 inflammasome activation. Neutralization of cell-free DNA by DNase treatment or inhibition of inflammasome activation reduced the rate of stroke recurrence after experimental stroke. Our findings present an explanation for the high recurrence rate after incident ischaemic events in patients with atherosclerosis. The detailed mechanisms uncovered here provide clinically uncharted therapeutic targets for which we show high efficacy to prevent recurrent events. Targeting DNA-mediated inflammasome activation after remote tissue injury represents a promising avenue for further clinical development in the prevention of early recurrent events.


Asunto(s)
Aterosclerosis , Ácidos Nucleicos Libres de Células , Proteínas de Unión al ADN , Modelos Animales de Enfermedad , Inflamasomas , Placa Aterosclerótica , Recurrencia , Accidente Cerebrovascular , Animales , Inflamasomas/metabolismo , Ratones , Masculino , Aterosclerosis/metabolismo , Aterosclerosis/patología , Aterosclerosis/inmunología , Humanos , Placa Aterosclerótica/metabolismo , Placa Aterosclerótica/patología , Proteínas de Unión al ADN/metabolismo , Proteínas de Unión al ADN/genética , Accidente Cerebrovascular/inmunología , Accidente Cerebrovascular/metabolismo , Accidente Cerebrovascular/complicaciones , Ácidos Nucleicos Libres de Células/sangre , Ácidos Nucleicos Libres de Células/metabolismo , Ácidos Nucleicos Libres de Células/genética , Femenino , Trampas Extracelulares/metabolismo , Infarto del Miocardio/metabolismo , Infarto del Miocardio/patología , Infarto del Miocardio/inmunología , Neutrófilos/inmunología , Neutrófilos/metabolismo , Inflamación/patología , Ratones Endogámicos C57BL
7.
Nature ; 631(8021): 645-653, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38987596

RESUMEN

Platelet homeostasis is essential for vascular integrity and immune defence1,2. Although the process of platelet formation by fragmenting megakaryocytes (MKs; thrombopoiesis) has been extensively studied, the cellular and molecular mechanisms required to constantly replenish the pool of MKs by their progenitor cells (megakaryopoiesis) remains unclear3,4. Here we use intravital imaging to track the cellular dynamics of megakaryopoiesis over days. We identify plasmacytoid dendritic cells (pDCs) as homeostatic sensors that monitor the bone marrow for apoptotic MKs and deliver IFNα to the MK niche triggering local on-demand proliferation and maturation of MK progenitors. This pDC-dependent feedback loop is crucial for MK and platelet homeostasis at steady state and under stress. pDCs are best known for their ability to function as vigilant detectors of viral infection5. We show that virus-induced activation of pDCs interferes with their function as homeostatic sensors of megakaryopoiesis. Consequently, activation of pDCs by SARS-CoV-2 leads to excessive megakaryopoiesis. Together, we identify a pDC-dependent homeostatic circuit that involves innate immune sensing and demand-adapted release of inflammatory mediators to maintain homeostasis of the megakaryocytic lineage.


Asunto(s)
Células Dendríticas , Homeostasis , Megacariocitos , Trombopoyesis , Animales , Femenino , Humanos , Masculino , Ratones , Apoptosis , Plaquetas/citología , Médula Ósea , Linaje de la Célula , Proliferación Celular , Células Dendríticas/inmunología , Células Dendríticas/citología , Retroalimentación Fisiológica , Inmunidad Innata , Microscopía Intravital , Megacariocitos/citología , Megacariocitos/inmunología , Ratones Endogámicos C57BL , SARS-CoV-2/inmunología , COVID-19/inmunología , COVID-19/fisiopatología , COVID-19/virología
8.
Nature ; 592(7853): 296-301, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33731931

RESUMEN

Clonal haematopoiesis, which is highly prevalent in older individuals, arises from somatic mutations that endow a proliferative advantage to haematopoietic cells. Clonal haematopoiesis increases the risk of myocardial infarction and stroke independently of traditional risk factors1. Among the common genetic variants that give rise to clonal haematopoiesis, the JAK2V617F (JAK2VF) mutation, which increases JAK-STAT signalling, occurs at a younger age and imparts the strongest risk of premature coronary heart disease1,2. Here we show increased proliferation of macrophages and prominent formation of necrotic cores in atherosclerotic lesions in mice that express Jak2VF selectively in macrophages, and in chimeric mice that model clonal haematopoiesis. Deletion of the essential inflammasome components caspase 1 and 11, or of the pyroptosis executioner gasdermin D, reversed these adverse changes. Jak2VF lesions showed increased expression of AIM2, oxidative DNA damage and DNA replication stress, and Aim2 deficiency reduced atherosclerosis. Single-cell RNA sequencing analysis of Jak2VF lesions revealed a landscape that was enriched for inflammatory myeloid cells, which were suppressed by deletion of Gsdmd. Inhibition of the inflammasome product interleukin-1ß reduced macrophage proliferation and necrotic formation while increasing the thickness of fibrous caps, indicating that it stabilized plaques. Our findings suggest that increased proliferation and glycolytic metabolism in Jak2VF macrophages lead to DNA replication stress and activation of the AIM2 inflammasome, thereby aggravating atherosclerosis. Precise application of therapies that target interleukin-1ß or specific inflammasomes according to clonal haematopoiesis status could substantially reduce cardiovascular risk.


Asunto(s)
Aterosclerosis/patología , Hematopoyesis Clonal , Proteínas de Unión al ADN/metabolismo , Inflamasomas/metabolismo , Animales , Anticuerpos/inmunología , Anticuerpos/uso terapéutico , Aterosclerosis/tratamiento farmacológico , Aterosclerosis/inmunología , Médula Ósea/metabolismo , Caspasa 1/metabolismo , Caspasas Iniciadoras/metabolismo , Modelos Animales de Enfermedad , Femenino , Humanos , Inflamación/metabolismo , Inflamación/patología , Proteína Antagonista del Receptor de Interleucina 1/farmacología , Proteína Antagonista del Receptor de Interleucina 1/uso terapéutico , Interleucina-1beta/inmunología , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Janus Quinasa 2/genética , Janus Quinasa 2/metabolismo , Macrófagos/patología , Ratones , Ratones Endogámicos C57BL , Proteínas de Unión a Fosfato/metabolismo , Piroptosis , RNA-Seq , Análisis de la Célula Individual
9.
Immunol Rev ; 314(1): 357-375, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36315403

RESUMEN

Over the past millennia, life expectancy has drastically increased. While a mere 25 years during Bronze and Iron ages, life expectancy in many European countries and in Japan is currently above 80 years. Such an increase in life expectancy is a result of improved diet, life style, and medical care. Yet, increased life span and aging also represent the most important non-modifiable risk factors for several pathologies including cardiovascular disease, neurodegenerative diseases, and cancer. In recent years, neutrophils have been implicated in all of these pathologies. Hence, this review provides an overview of how aging impacts neutrophil production and function and conversely how neutrophils drive aging-associated pathologies. Finally, we provide a perspective on how processes of neutrophil-driven pathologies in the context of aging can be targeted therapeutically.


Asunto(s)
Envejecimiento , Neutrófilos , Humanos , Longevidad , Esperanza de Vida , Factores de Riesgo
10.
Blood ; 143(15): 1539-1550, 2024 Apr 11.
Artículo en Inglés | MEDLINE | ID: mdl-38142422

RESUMEN

ABSTRACT: JAK2 V617F (JAK2VF) clonal hematopoiesis (CH) has been associated with atherothrombotic cardiovascular disease (CVD). We assessed the impact of Jak2VF CH on arterial thrombosis and explored the underlying mechanisms. A meta-analysis of 3 large cohort studies confirmed the association of JAK2VF with CVD and with platelet counts and adjusted mean platelet volume (MPV). In mice, 20% or 1.5% Jak2VF CH accelerated arterial thrombosis and increased platelet activation. Megakaryocytes in Jak2VF CH showed elevated proplatelet formation and release, increasing prothrombogenic reticulated platelet counts. Gp1ba-Cre-mediated expression of Jak2VF in platelets (VFGp1ba) increased platelet counts to a similar level as in 20% Jak2VF CH mice while having no effect on leukocyte counts. Like Jak2VF CH mice, VFGp1ba mice showed enhanced platelet activation and accelerated arterial thrombosis. In Jak2VF CH, both Jak2VF and wild-type (WT) platelets showed increased activation, suggesting cross talk between mutant and WT platelets. Jak2VF platelets showed twofold to threefold upregulation of COX-1 and COX-2, particularly in young platelets, with elevated cPLA2 activation and thromboxane A2 production. Compared with controls, conditioned media from activated Jak2VF platelets induced greater activation of WT platelets that was reversed by a thromboxane receptor antagonist. Low-dose aspirin ameliorated carotid artery thrombosis in VFGp1ba and Jak2VF CH mice but not in WT control mice. This study shows accelerated arterial thrombosis and platelet activation in Jak2VF CH with a major role of increased reticulated Jak2VF platelets, which mediate thromboxane cross talk with WT platelets and suggests a potential beneficial effect of aspirin in JAK2VF CH.


Asunto(s)
Hematopoyesis Clonal , Trombosis , Animales , Humanos , Ratones , Aspirina/farmacología , Aspirina/uso terapéutico , Plaquetas/metabolismo , Ratones Noqueados , Activación Plaquetaria , Trombosis/genética , Trombosis/metabolismo
11.
Gut ; 73(3): 407-441, 2024 02 23.
Artículo en Inglés | MEDLINE | ID: mdl-38383142

RESUMEN

At the end of the last century, a far-sighted 'working party' held in Sydney, Australia addressed the clinicopathological issues related to gastric inflammatory diseases. A few years later, an international conference held in Houston, Texas, USA critically updated the seminal Sydney classification. In line with these initiatives, Kyoto Global Consensus Report, flanked by the Maastricht-Florence conferences, added new clinical evidence to the gastritis clinicopathological puzzle.The most relevant topics related to the gastric inflammatory diseases have been addressed by the Real-world Gastritis Initiative (RE.GA.IN.), from disease definitions to the clinical diagnosis and prognosis. This paper reports the conclusions of the RE.GA.IN. consensus process, which culminated in Venice in November 2022 after more than 8 months of intense global scientific deliberations. A forum of gastritis scholars from five continents participated in the multidisciplinary RE.GA.IN. consensus. After lively debates on the most controversial aspects of the gastritis spectrum, the RE.GA.IN. Faculty amalgamated complementary knowledge to distil patient-centred, evidence-based statements to assist health professionals in their real-world clinical practice. The sections of this report focus on: the epidemiology of gastritis; Helicobacter pylori as dominant aetiology of environmental gastritis and as the most important determinant of the gastric oncogenetic field; the evolving knowledge on gastric autoimmunity; the clinicopathological relevance of gastric microbiota; the new diagnostic horizons of endoscopy; and the clinical priority of histologically reporting gastritis in terms of staging. The ultimate goal of RE.GA.IN. was and remains the promotion of further improvement in the clinical management of patients with gastritis.


Asunto(s)
Gastritis , Infecciones por Helicobacter , Helicobacter pylori , Neoplasias Gástricas , Humanos , Infecciones por Helicobacter/complicaciones , Infecciones por Helicobacter/diagnóstico , Infecciones por Helicobacter/patología , Gastritis/diagnóstico , Gastritis/epidemiología , Gastritis/patología , Endoscopía , Neoplasias Gástricas/patología , Mucosa Gástrica/patología
12.
J Am Chem Soc ; 146(32): 22220-22235, 2024 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-39088252

RESUMEN

High-voltage layered oxide cathodes attract great attention for sodium-ion batteries (SIBs) due to the potential high energy density, but high voltage usually leads to rapid capacity decay. Herein, a stable high-voltage NaLi0.1Ni0.35Mn0.3Ti0.25O2 cathode with a ribbon-ordered superlattice is reported, and the intrinsic coupling mechanism between structure evolution and the anion redox reaction (ARR) is revealed. Li introduction constructs a special Li-O-Na configuration activating reversible nonbonded O 2p (|O2p)-type ARR and regulates the structure evolution way, enabling the reversible Li ions out-of-layer migration instead of the irreversible transition metal ions out-of-layer migration. The reversible structure evolution enhances the reversibility of the bonded O 2p (O2p)-type ARR and inhibits the generation of oxygen dimers, thus suppressing the irreversible molecular oxygen (O2)-type ARR. After the structure regulation, the structure evolution becomes reversible, |O2p-type ARR is activated, O2p-type ARR becomes stable, and O2-type ARR is inhibited, which largely suppresses the capacity degradation and voltage decay. The discharge capacity is increased from 154 to 168 mA h g-1, the capacity retention after 200 cycles significantly increases from 35 to 84%, and the voltage retention increases from 78 to 93%. This study presents some guidance for the design of high-voltage, O3-type oxide cathodes for high-performance SIBs.

13.
Lancet ; 402(10400): 451-463, 2023 08 05.
Artículo en Inglés | MEDLINE | ID: mdl-37423228

RESUMEN

BACKGROUND: Despite immunotherapy advancements for patients with advanced or metastatic non-small-cell lung cancer (NSCLC), pivotal first-line trials were limited to patients with an Eastern Cooperative Oncology Group performance status (ECOG PS) 0-1 and a median age of 65 years or younger. We aimed to compare the efficacy and safety of first-line atezolizumab monotherapy with single-agent chemotherapy in patients ineligible for platinum-based chemotherapy. METHODS: This trial was a phase 3, open-label, randomised controlled study conducted at 91 sites in 23 countries across Asia, Europe, North America, and South America. Eligible patients had stage IIIB or IV NSCLC in whom platinum-doublet chemotherapy was deemed unsuitable by the investigator due to an ECOG PS 2 or 3, or alternatively, being 70 years or older with an ECOG PS 0-1 with substantial comorbidities or contraindications for platinum-doublet chemotherapy. Patients were randomised 2:1 by permuted-block randomisation (block size of six) to receive 1200 mg of atezolizumab given intravenously every 3 weeks or single-agent chemotherapy (vinorelbine [oral or intravenous] or gemcitabine [intravenous]; dosing per local label) at 3-weekly or 4-weekly cycles. The primary endpoint was overall survival assessed in the intention-to-treat population. Safety analyses were conducted in the safety-evaluable population, which included all randomised patients who received any amount of atezolizumab or chemotherapy. This trial is registered with ClinicalTrials.gov, NCT03191786. FINDINGS: Between Sept 11, 2017, and Sept 23, 2019, 453 patients were enrolled and randomised to receive atezolizumab (n=302) or chemotherapy (n=151). Atezolizumab improved overall survival compared with chemotherapy (median overall survival 10·3 months [95% CI 9·4-11·9] vs 9·2 months [5·9-11·2]; stratified hazard ratio 0·78 [0·63-0·97], p=0·028), with a 2-year survival rate of 24% (95% CI 19·3-29·4) with atezolizumab compared with 12% (6·7-18·0) with chemotherapy. Compared with chemotherapy, atezolizumab was associated with stabilisation or improvement of patient-reported health-related quality-of-life functioning scales and symptoms and fewer grade 3-4 treatment-related adverse events (49 [16%] of 300 vs 49 [33%] of 147) and treatment-related deaths (three [1%] vs four [3%]). INTERPRETATION: First-line treatment with atezolizumab monotherapy was associated with improved overall survival, a doubling of the 2-year survival rate, maintenance of quality of life, and a favourable safety profile compared with single-agent chemotherapy. These data support atezolizumab monotherapy as a potential first-line treatment option for patients with advanced NSCLC who are ineligible for platinum-based chemotherapy. FUNDING: F Hoffmann-La Roche and Genentech Inc, a member of the Roche group.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Humanos , Anciano , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Platino (Metal)/uso terapéutico , Calidad de Vida , Neoplasias Pulmonares/tratamiento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico
14.
Gastroenterology ; 164(4): 550-566, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36587707

RESUMEN

BACKGROUND & AIMS: Infection with Helicobacter pylori strongly affects global health by causing chronic gastritis, ulcer disease, and gastric cancer. Although extensive research into the strong immune response against this persistently colonizing bacterium exists, the specific role of CD8+ T cells remains elusive. METHODS: We comprehensively characterize gastric H pylori-specific CD8+ T-cell responses in mice and humans by flow cytometry, RNA-sequencing, immunohistochemistry, and ChipCytometry, applying functional analyses including T-cell depletion, H pylori eradication, and ex vivo restimulation. RESULTS: We define CD8+ T-cell populations bearing a tissue-resident memory (TRM) phenotype, which infiltrate the gastric mucosa shortly after infection and mediate pathogen control by executing antigen-specific effector properties. These induced CD8+ tissue-resident memory T cells (TRM cells) show a skewed T-cell receptor beta chain usage and are mostly specific for cytotoxin-associated gene A, the distinctive oncoprotein injected by H pylori into host cells. As the infection progresses, we observe a loss of the TRM phenotype and replacement of CD8+ by CD4+ T cells, indicating a shift in the immune response during the chronic infection phase. CONCLUSIONS: Our results point toward a hitherto unknown role of CD8+ T-cell response in this bacterial infection, which may have important clinical implications for treatment and vaccination strategies against H pylori.


Asunto(s)
Infecciones por Helicobacter , Helicobacter pylori , Humanos , Animales , Ratones , Linfocitos T CD8-positivos , Linfocitos T CD4-Positivos , Estómago , Mucosa Gástrica/microbiología , Infecciones por Helicobacter/microbiología , Antígenos Bacterianos , Proteínas Bacterianas
15.
Small ; : e2402991, 2024 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-38958092

RESUMEN

In P2-type layered oxide cathodes, Na site-regulation strategies are proposed to modulate the Na+ distribution and structural stability. However, their impact on the oxygen redox reactions remains poorly understood. Herein, the incorporation of K+ in the Na layer of Na0.67Ni0.11Cu0.22Mn0.67O2 is successfully applied. The effects of partial substitution of Na+ with K+ on electrochemical properties, structural stability, and oxygen redox reactions have been extensively studied. Improved Na+ diffusion kinetics of the cathode is observed from galvanostatic intermittent titration technique (GITT) and rate performance. The valence states and local structural environment of the transition metals (TMs) are elucidated via operando synchrotron X-ray absorption spectroscopy (XAS). It is revealed that the TMO2 slabs tend to be strengthened by K-doping, which efficiently facilitates reversible local structural change. Operando X-ray diffraction (XRD) further confirms more reversible phase changes during the charge/discharge for the cathode after K-doping. Density functional theory (DFT) calculations suggest that oxygen redox reaction in Na0.62K0.03Ni0.11Cu0.22Mn0.67O2 cathode has been remarkably suppressed as the nonbonding O 2p states shift down in the energy. This is further corroborated experimentally by resonant inelastic X-ray scattering (RIXS) spectroscopy, ultimately proving the role of K+ incorporated in the Na layer.

16.
Blood ; 139(17): 2691-2705, 2022 04 28.
Artículo en Inglés | MEDLINE | ID: mdl-35313337

RESUMEN

The prevention and treatment of arterial thrombosis continue to be clinically challenging, and understanding the relevant molecular mechanisms in detail may facilitate the quest to identify novel targets and therapeutic approaches that improve protection from ischemic and bleeding events. The chemokine CXCL12 augments collagen-induced platelet aggregation by activating its receptor CXCR4. Here we show that inhibition of CXCR4 attenuates platelet aggregation induced by collagen or human plaque homogenate under static and arterial flow conditions by antagonizing the action of platelet-secreted CXCL12. We further show that platelet-specific CXCL12 deficiency in mice limits arterial thrombosis by affecting thrombus growth and stability without increasing tail bleeding time. Accordingly, neointimal lesion formation after carotid artery injury was attenuated in these mice. Mechanistically, CXCL12 activated via CXCR4 a signaling cascade involving Bruton's tyrosine kinase (Btk) that led to integrin αIIbß3 activation, platelet aggregation, and granule release. The heterodimeric interaction between CXCL12 and CCL5 can inhibit CXCL12-mediated effects as mimicked by CCL5-derived peptides such as [VREY]4. An improved variant of this peptide, i[VREY]4, binds to CXCL12 in a complex with CXCR4 on the surface of activated platelets, thereby inhibiting Btk activation and preventing platelet CXCL12-dependent arterial thrombosis. In contrast to standard antiplatelet therapies such as aspirin or P2Y12 inhibition, i[VREY]4 reduced CXCL12-induced platelet aggregation and yet did not prolong in vitro bleeding time. We provide evidence that platelet-derived CXCL12 is involved in arterial thrombosis and can be specifically targeted by peptides that harbor potential therapeutic value against atherothrombosis.


Asunto(s)
Plaquetas , Trombosis , Agammaglobulinemia Tirosina Quinasa/metabolismo , Animales , Plaquetas/metabolismo , Quimiocina CXCL12/metabolismo , Colágeno/metabolismo , Ratones , Activación Plaquetaria , Agregación Plaquetaria , Complejo GPIIb-IIIa de Glicoproteína Plaquetaria/metabolismo , Trombosis/metabolismo
17.
Haematologica ; 109(8): 2487-2499, 2024 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-38572559

RESUMEN

Innate myeloid cells especially neutrophils and their extracellular traps are known to promote intravascular coagulation and thrombosis formation in infections and various other conditions. Innate myeloid cell-dependent fibrin formation can support systemic immunity while its dysregulation enhances the severity of infectious diseases. Less is known about the immune mechanisms preventing dysregulation of fibrin homeostasis in infection. During experimental systemic infections local fibrin deposits in the liver microcirculation cause rapid arrest of CD4+ T cells. Arrested T-helper cells mostly represent Th17 cells that partially originate from the small intestine. Intravascular fibrin deposits activate mouse and human CD4+ T cells which can be mediated by direct fibrin-CD4+ T-cell interactions. Activated CD4+ T cells suppress fibrin deposition and microvascular thrombosis by directly counteracting coagulation activation by neutrophils and classical monocytes. T-cell activation, which is initially triggered by IL-12p40- and MHC-II-dependent mechanisms, enhances intravascular fibrinolysis via LFA-1. Moreover, CD4+ T cells disfavor the association of the thrombin-activatable fibrinolysis inhibitor (TAFI) with fibrin whereby fibrin deposition is increased by TAFI in the absence but not in the presence of T cells. In human infections thrombosis development is inversely related to microvascular levels of CD4+ T cells. Thus, fibrin promotes LFA-1-dependent T-helper cell activation in infections which drives a negative feedback cycle that rapidly restricts intravascular fibrin and thrombosis development.


Asunto(s)
Linfocitos T CD4-Positivos , Fibrina , Humanos , Fibrina/metabolismo , Animales , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/metabolismo , Infecciones/inmunología , Activación de Linfocitos/inmunología , Trombosis/etiología , Trombosis/inmunología
18.
Pancreatology ; 24(6): 840-846, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39147660

RESUMEN

BACKGROUND: With respect to severity and outcome of an index episode of idiopathic acute pancreatitis the current literature reports conflicting retrospective results. One reason might be the retrospective study design precluding in depth analysis resulting in mixed etiologies and combination of index episode versus recurrent idiopathic acute pancreatitis. METHODS: In this retrospective monocentric cohort study, we retrieved all patients with a first acute pancreatitis episode treated between 2005 and 2021 at the LMU University Hospital from our clinical information system based on the respective ICD-10 codes. In an initial sample of 1390 presumed idiopathic pancreatitis patients we identified 68 confirmed idiopathic acute pancreatitis patients and compared those to 75 first-time alcohol-induced acute pancreatitis patients and 390 first-time biliary-induced acute pancreatitis patients. Clinical outcome (severity, SIRS, mortality, and re-admission rate) was set as outcome measures. Multinomial logistic regression analysis was performed. RESULTS: In alcohol-induced acute pancreatitis moderate and severe courses occur significantly more often when compared to idiopathic acute pancreatitis (17.33 % vs. 10.29 %; multinomial logistic regression p = 0.0021). There were no significant differences in mortality between first-time alcoholic, idiopathic and biliary pancreatitis (p = 0.6328). Patients with idiopathic acute pancreatitis had significantly more hospital readmissions (within 30 days) compared to alcohol-induced pancreatitis patients (p = 0.0284). CONCLUSION: In the context of a first episode of acute pancreatitis, idiopathic acute pancreatitis remains a challenging diagnosis posing an increased risk of recurrence, but not an increased risk for a more severe disease course.


Asunto(s)
Pancreatitis , Índice de Severidad de la Enfermedad , Humanos , Pancreatitis/complicaciones , Pancreatitis/mortalidad , Pancreatitis/etiología , Masculino , Femenino , Estudios Retrospectivos , Persona de Mediana Edad , Anciano , Adulto , Pancreatitis Alcohólica/complicaciones , Estudios de Cohortes , Enfermedad Aguda , Recurrencia , Readmisión del Paciente , Resultado del Tratamiento
19.
Dig Dis ; 42(4): 299-308, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38447558

RESUMEN

BACKGROUND: Helicobacter pylori (H. pylori) was discovered 40 years ago and has set a milestone in human medicine. The discovery led to rejection of the dogma of the acidic stomach as a sterile organ and requested to rewrite the chapters on gastric pathophysiology and gastroduodenal diseases. SUMMARY: Over a period of 40 years following the discovery, more than 50,000 articles can be retrieved in PubMed as of today and illustrate the amount and the intensity of research around the role of this bacterium. H. pylori emerged as cause of chronic gastritis and principal cause of peptic ulcer disease (PUD). Eradication of H. pylori became standard of care in management in PUD. The importance of this was highlighted in 2005 with the Nobel Prize in Medicine awarded to Barry Marshall and Robin Warren. H. pylori became eventually recognized for its oncogenic potential in the stomach and as the main risk factor for gastric cancer development. KEY MESSAGES: H. pylori gastritis is defined as infectious disease and requires therapy in all infected individuals. Strategies of gastric cancer prevention and development of therapies to overcome the increasing antibiotic resistance are main targets in clinical research of today.


Asunto(s)
Infecciones por Helicobacter , Helicobacter pylori , Humanos , Infecciones por Helicobacter/tratamiento farmacológico , Infecciones por Helicobacter/complicaciones , Úlcera Péptica/microbiología , Úlcera Péptica/terapia , Úlcera Péptica/tratamiento farmacológico , Historia del Siglo XX , Gastritis/microbiología , Gastritis/terapia , Antibacterianos/uso terapéutico , Neoplasias Gástricas/microbiología , Neoplasias Gástricas/terapia , Historia del Siglo XXI
20.
Dig Dis ; 42(3): 240-256, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38493766

RESUMEN

BACKGROUND: Helicobacter pylori (H. pylori) infection is the most prevalent type of bacterial infection. Current guidelines from different regions of the world neglect specific African conditions and requirements. The African Helicobacter and Microbiota Study Group (AHMSG), founded in 2022, aimed to create an Africa-specific consensus report reflecting Africa-specific issues. SUMMARY: Eighteen experts from nine African countries and two European delegates supported by nine African collaborators from eight other countries prepared statements on the most important African issues in four working groups: (1) epidemiology, (2) diagnosis, (3) indications and prevention, and (4) treatment. Limited resources, restricted access to medical systems, and underdeveloped diagnostic facilities differ from those of other regions. The results of the individual working groups were presented for the final consensus voting, which included all board members. KEY MESSAGES: There is a need for further studies on H. pylori prevalence in Africa, with diagnosis hinged on specific African situation. Treatment of H. pylori in the African setting should be based on accessibility and reimbursement, while indication and prevention should be defined in specific African countries.


Asunto(s)
Consenso , Infecciones por Helicobacter , Helicobacter pylori , Infecciones por Helicobacter/diagnóstico , Infecciones por Helicobacter/tratamiento farmacológico , Infecciones por Helicobacter/epidemiología , Infecciones por Helicobacter/terapia , Humanos , África/epidemiología , Prevalencia
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