CD4(+) T cell anergy prevents autoimmunity and generates regulatory T cell precursors.

The role of anergy, an acquired state of T cell functional unresponsiveness, in natural peripheral tolerance remains unclear. In this study, we found that anergy was selectively induced in fetal antigen-specific maternal CD4(+) T cells during pregnancy. A naturally occurring subpopulation of anergic polyclonal CD4(+) T cells, enriched for self antigen-specific T cell antigen receptors, was also present in healthy hosts. Neuropilin-1 expression in anergic conventional CD4(+) T cells was associated with hypomethylation of genes related to thymic regulatory T cells (Treg cells), and this correlated with their ability to differentiate into Foxp3(+) Treg cells that suppressed immunopathology. Thus, our data suggest that not only is anergy induction important in preventing autoimmunity but also it generates the precursors for peripheral Treg cell differentiation.

Immune tolerance of food is mediated by layers of CD4+ T cell dysfunction.

Gastrointestinal health depends on the adaptive immune system tolerating the foreign proteins in food1,2. This tolerance is paradoxical because the immune system normally attacks foreign substances by generating inflammation. Here we addressed this conundrum by using a sensitive cell enrichment method to show that polyclonal CD4+ T cells responded to food peptides, including a natural one from gliadin, by proliferating weakly in secondary lymphoid organs of the gut-liver axis owing to the action of regulatory T cells. A few food-specific T cells then differentiated into T follicular helper cells that promoted a weak antibody response. Most cells in the expanded population, however, lacked canonical T helper lineage markers and fell into five subsets dominated by naive-like or T follicular helper-like anergic cells with limited capacity to form inflammatory T helper 1 cells. Eventually, many of the T helper lineage-negative cells became regulatory T cells themselves through an interleukin-2-dependent mechanism. Our results indicate that exposure to food antigens causes cognate CD4+ naive T cells to form a complex set of noncanonical hyporesponsive T helper cell subsets that lack the inflammatory functions needed to cause gut pathology and yet have the potential to produce regulatory T cells that may suppress it.

Pharmacogenomic insights in psychiatric care: uncovering novel actionability, allele-specific CYP2D6 copy number variation, and phenoconversion in 15,000 patients.

Pharmacogenomic testing has emerged as an aid in clinical decision making for psychiatric providers, but more data is needed regarding its utility in clinical practice and potential impact on patient care. In this cross-sectional study, we determined the real-world prevalence of pharmacogenomic actionability in patients receiving psychiatric care. Potential actionability was based on the prevalence of CYP2C19 and CYP2D6 phenotypes, including CYP2D6 allele-specific copy number variations (CNVs). Combined actionability additionally incorporated CYP2D6 phenoconversion and the novel CYP2C-TG haplotype in patients with available medication data. Across 15,000 patients receiving clinical pharmacogenomic testing, 65% had potentially actionable CYP2D6 and CYP2C19 phenotypes, and phenotype assignment was impacted by CYP2D6 allele-specific CNVs in 2% of all patients. Of 4114 patients with medication data, 42% had CYP2D6 phenoconversion from drug interactions and 20% carried a novel CYP2C haplotype potentially altering actionability. A total of 87% had some form of potential actionability from genetic findings and/or phenoconversion. Genetic variation detected via next-generation sequencing led to phenotype reassignment in 22% of individuals overall (2% in CYP2D6 and 20% in CYP2C19). Ultimately, pharmacogenomic testing using next-generation sequencing identified potential actionability in most patients receiving psychiatric care. Early pharmacogenomic testing may provide actionable insights to aid clinicians in drug prescribing to optimize psychiatric care.

Strong homeostatic TCR signals induce formation of self-tolerant virtual memory CD8 T cells.

Virtual memory T cells are foreign antigen-inexperienced T cells that have acquired memory-like phenotype and constitute 10-20% of all peripheral CD8+ T cells in mice. Their origin, biological roles, and relationship to naïve and foreign antigen-experienced memory T cells are incompletely understood. By analyzing T-cell receptor repertoires and using retrogenic monoclonal T-cell populations, we demonstrate that the virtual memory T-cell formation is a so far unappreciated cell fate decision checkpoint. We describe two molecular mechanisms driving the formation of virtual memory T cells. First, virtual memory T cells originate exclusively from strongly self-reactive T cells. Second, the stoichiometry of the CD8 interaction with Lck regulates the size of the virtual memory T-cell compartment via modulating the self-reactivity of individual T cells. Although virtual memory T cells descend from the highly self-reactive clones and acquire a partial memory program, they are not more potent in inducing experimental autoimmune diabetes than naïve T cells. These data underline the importance of the variable level of self-reactivity in polyclonal T cells for the generation of functional T-cell diversity.

Mechanisms maintaining peripheral tolerance.

The presentation of self-peptide-MHC complexes in the periphery to potentially autoreactive T cells that have escaped negative selection in the thymus poses an important problem to the immune system. In this review, I discuss data that reveal barriers preventing peripheral T cell recognition of self-peptide-MHC complexes, as well as the physiological mechanisms that ensure the elimination or functional inactivation (anergy) of T cells that do come to recognize self-peptide-MHC and threaten the health of the individual.

Older molecular brain age in severe mental illness.

Psychiatric disorders are associated with accelerated aging and enhanced risk for neurodegenerative disorders. Brain aging is associated with molecular, cellular, and structural changes that are robust on the group level, yet show substantial inter-individual variability. Here we assessed deviations in gene expression from normal age-dependent trajectories, and tested their validity as predictors of risk for major mental illnesses and neurodegenerative disorders. We performed large-scale gene expression and genotype analyses in postmortem samples of two frontal cortical brain regions from 214 control subjects aged 20-90 years. Individual estimates of "molecular age" were derived from age-dependent genes, identified by robust regression analysis. Deviation from chronological age was defined as "delta age". Genetic variants associated with deviations from normal gene expression patterns were identified by expression quantitative trait loci (cis-eQTL) of age-dependent genes or genome-wide association study (GWAS) on delta age, combined into distinct polygenic risk scores (PRScis-eQTL and PRSGWAS), and tested for predicting brain disorders or pathology in independent postmortem expression datasets and clinical cohorts. In these validation datasets, molecular ages, defined by 68 and 76 age-related genes for two brain regions respectively, were positively correlated with chronological ages (r = 0.88/0.91), elevated in bipolar disorder (BP) and schizophrenia (SCZ), and unchanged in major depressive disorder (MDD). Exploratory analyses in independent clinical datasets show that PRSs were associated with SCZ and MDD diagnostics, and with cognition in SCZ and pathology in Alzheimer's disease (AD). These results suggest that older molecular brain aging is a common feature of severe mental illnesses and neurodegeneration.

How wide should you view to fight? Establishing the size of the visual field necessary for grip fighting in judo.

Peripheral vision is often considered vital in (combat) sports, yet most experimental paradigms (e.g., eye tracking) ignore peripheral information or struggle to make inferences about the role of peripheral vision in an in-situ performance environment. This study aimed to determine where visual information is located in the peripheral field during an in-situ combat sports task. Eight advanced judokas competed in grip-fighting exchanges while wearing a mobile eye-tracker to locate gaze direction. Three-dimensional position data of the head and hands were tracked using a VICON motion capture system. Gaze analysis through automatic feature detection showed that participants predominantly fixated on their opponent's chest. Kinematic data were used to calculate the angles between the opponent's hands and the gaze-anchor point on the chest of the opponent. Results revealed a nonlinear relationship between visual field (VF) size and visibility of the hands, with athletes needing a VF of at least 30-40 degrees radius to simultaneously monitor both hands of the opponent most of the time. These findings hold implications for the regulation of Paralympic judo for athletes with vision impairment, suggesting that a less severe degree of impairment should be required to qualify than the current criterion of 20 degrees radius.

Efficacy and Safety of Letibotulinumtoxin A in the Treatment of Glabellar Lines: A Randomized, Double-Blind, Multicenter, Placebo-Controlled Phase 3 Study.

BACKGROUND: Letibotulinumtoxin A (Hugel, Inc., Chuncheon, Republic of Korea and CROMA Pharma, Leobendorf, Austria) is a newly manufactured neurotoxin derived from Clostridium botulinum strain CBFC26. OBJECTIVES: The aim of this study was to assess the efficacy and safety of letibotulinumtoxin A in reducing glabellar line severity (GLS) and to evaluate long-term safety and efficacy following repeated injections. METHODS: In this prospective, randomized, parallel-group, double-blind, multicentre, placebo-controlled Phase III clinical trial, 355 subjects with moderate to severe glabella frown lines received injections of 20 U of letibotulinumtoxin A or placebo. GLS, onset and duration of effect, time to retreatment, and adverse events were evaluated. Response to treatment was defined as a GLS score of 0 or 1 (assessed by the subject and the investigator) and an improvement at Week 4 of ≥2 points in GLS score relative to baseline. RESULTS: At 4 weeks, 78.6% of the active treatment subjects were responders based on the investigator's assessment and 68.8% based on the subject's assessment, resulting in a composite responder rate of 64.7% for the active treatment group, whereas the corresponding rate was 0.0% in the placebo group (P < 0.001). Subjects noted a substantial improvement in GL severity as early as Day 2, with the median time to onset of effect being 3 days. The mean [standard deviation] time until first retreatment for the letibotulinumtoxin A group was 127.26 [65.6] days. Letibotulinumtoxin A was well tolerated. CONCLUSIONS: Letibotulinumtoxin A demonstrates high efficacy and a convincing safety profile in the treatment of glabellar lines.

Brigatinib versus other second-generation ALK inhibitors as initial treatment of anaplastic lymphoma kinase positive non-small cell lung cancer with deep phenotyping: study protocol of the ABP trial.

BACKGROUND: Availability of potent anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitors (TKI) has pushed the median survival of ALK+ non-smallcell lung cancer (NSCLC) patients to over five years. In particular, second-generation ALK TKI have demonstrated superiority compared to the first-generation compound crizotinib and are meanwhile standard first-line treatment. However, clinical courses of individual patients vary widely, with secondary development of drug resistance and intracranial progression remaining important problems. While these limitations highlight the need for better disease monitoring and additional therapeutic tools, molecular tumor features are increasingly recognized as crucial determinants of clinical outcome. This trial aims to optimize management of ALK+ NSCLC by analyzing the efficacy of second-generation ALK inhibitors in conjunction with deep longitudinal phenotyping across two treatment lines. METHODS/DESIGN: In this exploratory prospective phase II clinical trial, newly diagnosed ALK+ NSCLC patients will be randomized into two treatment arms, stratified by presence of brain metastases and ECOG performance status: brigatinib (experimental arm) vs. any other approved second-generation ALK TKI. Tumor tissue and blood samples will be collected for biomarker analysis at the beginning and throughout the study period to investigate baseline molecular tumor properties and analyze the development of acquired drug resistance. In addition, participating investigators and patients will have the possibility of fast-track molecular tumor and ctDNA profiling at the time of disease progression using state-of-the-art next-generation sequencing (NGS), in order to support decisions regarding next-line therapy. DISCUSSION: Besides supporting therapeutic decisions for enrolled patients, the ABP trial primarily aims to deepen the understanding of the underlying biology and facilitate development of a framework for individualized management of ALK+ NSCLC according to molecular features. Patients with low molecular risk and the perspective of a "chronic disease" will be distinguished from "high-risk" cases, molecular properties of which will be utilized to elaborate improved methods of non-invasive monitoring and novel preclinical models in order to advance therapeutic strategies. TRIAL REGISTRATION: Clinicaltrials.gov , NCT04318938. Registered March 182,020, https://www.clinicaltrials.gov/ct2/show/NCT04318938 Eudra-CT, 2019-001828-36. Registered September 302,019, https://www.clinicaltrialsregister.eu/ctr-search/search?query=2019-001828-36.

Effect of Systemic Inflammatory Response to SARS-CoV-2 on Lopinavir and Hydroxychloroquine Plasma Concentrations.

Coronavirus disease 2019 (COVID-19) leads to inflammatory cytokine release, which can downregulate the expression of metabolizing enzymes. This cascade affects drug concentrations in the plasma. We investigated the association between lopinavir (LPV) and hydroxychloroquine (HCQ) plasma concentrations and the levels of the acute-phase inflammation marker C-reactive protein (CRP). LPV plasma concentrations in 92 patients hospitalized at our institution were prospectively collected. Lopinavir-ritonavir was administered every 12 hours, 800/200 mg on day 1 and 400/100 mg on day 2 until day 5 or 7. HCQ was given at 800 mg, followed by 400 mg after 6, 24, and 48 h. Hematological, liver, kidney, and inflammation laboratory values were analyzed on the day of drug level determination. The median age of study participants was 59 (range, 24 to 85) years, and 71% were male. The median durations from symptom onset to hospitalization and treatment initiation were 7 days (interquartile range [IQR], 4 to 10) and 8 days (IQR, 5 to 10), respectively. The median LPV trough concentration on day 3 of treatment was 26.5 µg/ml (IQR, 18.9 to 31.5). LPV plasma concentrations positively correlated with CRP values (r = 0.37, P < 0.001) and were significantly lower when tocilizumab was preadministered. No correlation was found between HCQ concentrations and CRP values. High LPV plasma concentrations were observed in COVID-19 patients. The ratio of calculated unbound drug fraction to published SARS-CoV-2 50% effective concentrations (EC50) indicated insufficient LPV concentrations in the lung. CRP values significantly correlated with LPV but not HCQ plasma concentrations, implying inhibition of cytochrome P450 3A4 (CYP3A4) metabolism by inflammation.

Thoracic radiotherapy plus Durvalumab in elderly and/or frail NSCLC stage III patients unfit for chemotherapy - employing optimized (hypofractionated) radiotherapy to foster durvalumab efficacy: study protocol of the TRADE-hypo trial.

BACKGROUND: Non-small cell lung cancer is the most common cause of cancer death worldwide, highlighting the need for novel therapeutic concepts. In particular, there is still a lack of treatment strategies for the group of elderly and frail patients, who are frequently not capable of receiving standard therapy regimens. Despite comprising the majority of lung cancer patients, this group is underrepresented in clinical trials. This applies also to elderly and frail patients suffering from unresectable stage III NSCLC, who are unfit for chemotherapy, and, therefore, cannot receive the standard therapy comprising of radiochemotherapy and the recently approved subsequent durvalumab consolidation therapy. These patients often receive radiotherapy only, which raises the concern of undertreatment. The TRADE-hypo trial aims at optimizing treatment of this patient group by combining radiotherapy with concomitant durvalumab administration, thereby employing the immune-promoting effects of radiotherapy, and determining safety, feasibility, and efficacy of this treatment. METHODS/ DESIGN: In this prospective phase II clinical trial, durvalumab therapy will be combined with either conventionally fractionated (CON-group) or hypofractionated (HYPO-group) thoracic radiotherapy. A safety stop-and-go lead-in phase will assess safety of hypofractionated radiotherapy with respect to severe pneumonitis in small patient cohorts before opening full enrollment. Tumor tissue, blood and stool samples will be collected before and during the study period to investigate the immunological mechanisms responsible for checkpoint inhibitor efficacy and immune-promoting effects of radiotherapy. DISCUSSION: Preclinical data suggests that irradiation-induced immunogenicity can be further increased if applied in a hypofractionated setting, potentially boosting the expected synergistic effect with immune checkpoint inhibition in restoring the immune anti-tumor response. If proven safe and efficient, a hypofractionated radiation schedule can provide a considerably more practicable option for the patient. Taking into consideration the intend to develop a combination treatment strategy that can be made available to patients soon after proving to be efficient and the potentially elevated toxicity of a hypofractionated radiotherapy approach, this trial was designed as a two-trials-in-one design. An accompanying translational research program is planned striving to gain insights into the tumor-host biology and to identify suitable biomarkers to predict therapy response. TRIAL REGISTRATION: Clinicaltrials.gov , NCT04351256 . Registered 17 April 2020, Eudra-CT, 2019-002192-33 . Registered 24 October 2019.

MR Features of Juxta-Articular Venous Malformations of the Knee to Predict the Clinical Outcome of Sclerotherapy.

PURPOSE: To analyze and correlate preinterventional magnetic resonance (MR) imaging findings with clinical symptoms after percutaneous sclerotherapy of venous malformations (VMs) adjacent to the knee. MATERIALS AND METHODS: Twenty-five patients (mean age, 24 y; range, 7-55 y; 11 female) with 26 VMs adjacent to the knee undergoing sclerotherapy (direct puncture, diagnostic angiography, sclerosant injection) were identified, and MR imaging findings were analyzed. The VM involved the synovium of the knee joint in 19 of 26 cases (76%). These lesions were associated with joint effusion (3 of 19; 16%), hemarthrosis (4 of 19; 21%), or synovial thickening (16 of 19; 84%). Follow-up ended 6-8 weeks after the first or second sclerotherapy session if complete pain relief was achieved or 3 months after the third sclerotherapy session. Treatment outcomes were categorized as symptom improvement (complete or partial pain relief) or poor response (unchanged or increased pain). RESULTS: Forty-nine percutaneous sclerotherapy sessions were performed. Despite the absence of signs of knee osteoarthritis, patients with a VM involving the synovium (8 of 14; 57%) showed a poor response to sclerotherapy (1 of 8 [13%] pain-free after 1 sclerotherapy session). Among patients with VMs with no associated joint alteration and no synovial involvement (6 of 14; 43%), 5 of 6 (83%) showed improvement of symptoms after 1 sclerotherapy session (P < .05). CONCLUSIONS: Juxta-articular VMs of the knee are frequently associated with hemarthrosis and synovial thickening. Patients with signs of osteoarthritis and synovial involvement of the VM on presclerotherapy MR imaging deserve special consideration, as these findings predict worse clinical symptoms after sclerotherapy.

Can Cognitive Remediation in Groups Prevent Relapses?: Results of a 1-Year Follow-up Randomized Controlled Trial.

International guidelines define relapse prevention for schizophrenia patients as a key therapeutic aim. However, approximately 80% to 90% of schizophrenia patients experience further symptom exacerbation after the first episode. The purpose of this study was to investigate whether group integrated neurocognitive therapy (INT), a cognitive remediation approach, reduces relapse rates in schizophrenia outpatients. INT was compared with treatment as usual (TAU) in a randomized controlled trial. Fifty-eight stabilized outpatients participated in the study with 32 allocated to the INT group and 26 to the TAU group. A test battery was used at baseline, posttreatment at 15 weeks, and a 1-year follow-up. Relapse rates were significantly lower in the INT condition compared with TAU during therapy as well as at follow-up. The relapse rate after therapy was associated with significant reductions in negative and general symptoms, improvements in functional outcome, and overall cognition. Out of these variables, negative symptoms were identified to show the strongest association with relapses after therapy. The primary outcome of this study suggests that INT can prevent relapses in schizophrenia outpatients.

Variable domain N-linked glycosylation and negative surface charge are key features of monoclonal ACPA: Implications for B-cell selection.

Autoreactive B cells have a central role in the pathogenesis of rheumatoid arthritis (RA), and recent findings have proposed that anti-citrullinated protein autoantibodies (ACPA) may be directly pathogenic. Herein, we demonstrate the frequency of variable-region glycosylation in single-cell cloned mAbs. A total of 14 ACPA mAbs were evaluated for predicted N-linked glycosylation motifs in silico, and compared to 452 highly-mutated mAbs from RA patients and controls. Variable region N-linked motifs (N-X-S/T) were strikingly prevalent within ACPA (100%) compared to somatically hypermutated (SHM) RA bone marrow plasma cells (21%), and synovial plasma cells from seropositive (39%) and seronegative RA (7%). When normalized for SHM, ACPA still had significantly higher frequency of N-linked motifs compared to all studied mAbs including highly mutated HIV broadly-neutralizing and malaria-associated mAbs. The Fab glycans of ACPA-mAbs were highly sialylated, contributed to altered charge, but did not influence antigen binding. The analysis revealed evidence of unusual B-cell selection pressure and SHM-mediated decrease in surface charge and isoelectric point in ACPA. It is still unknown how these distinct features of anti-citrulline immunity may have an impact on pathogenesis. However, it is evident that they offer selective advantages for ACPA+ B cells, possibly through non-antigen driven mechanisms.

Relationship between CD4 Regulatory T Cells and Anergy In Vivo.

Selective suppression of effector CD4+ T cell functions is necessary to prevent immune cell-mediated damage to healthy tissues. This appears especially true during pregnancy or in individuals predisposed to autoimmunity. Foxp3+ regulatory T (Treg) cells and induction of anergy, an acquired state of T cell functional unresponsiveness in Foxp3- cells, have both been implicated as mechanisms to suppress dangerous immune responses to tissue-restricted self-Ags. Anergic CD4+ T cells and Treg cells share a number of phenotypic and mechanistic traits-including the expression of CD73 and folate receptor 4, and the epigenetic modification of Treg cell signature genes-and an interesting relationship between these two subsets has recently emerged. In this review, we will compare and contrast these two subsets, as well as explore the role of anergy in the generation of peripheral Treg cells.

Cutting Edge: Adenosine A2a Receptor Signals Inhibit Germinal Center T Follicular Helper Cell Differentiation during the Primary Response to Vaccination.

Adenosine A2a receptor (A2aR) signaling acts as a barrier to autoimmunity by promoting anergy, inducing regulatory T cells, and inhibiting effector T cells. However, in vivo effects of A2aR signaling on polyclonal CD4 T cells during a primary response to foreign Ag has yet to be determined. To address this problem, we immunized mice with peptide Ag 2W1S coupled to PE in CFA and treated with the selective A2aR agonist CGS-21680 (CGS). 2W1S:I-Ab-specific tetramer-binding CD4 T cells did not become anergic or differentiate into Foxp3+ regulatory T cells. Additionally, CGS treatment did not inhibit Th1 or Th17 differentiation. However, CGS did abrogate germinal center T follicular helper cells, and blunted PE-specific germinal center B cell responses. The use of A2aR-deficient CD4 T cells established that this CGS effect was T cell intrinsic. Therefore, this study has identified a unique role for A2aRs in regulating CD4 T cell differentiation during vaccination.

Integration of complementary biomarkers in patients with first episode psychosis: research protocol of a prospective follow up study.

In this project, we recruited a sample of 150 patients with first episode of psychosis with schizophrenia features (FEP) and 100 healthy controls. We assessed the differences between these two groups, as well as the changes between the acute phase of illness and subsequent remission among patients over 18-month longitudinal follow-up. The assessments were divided into four work packages (WP): WP1- psychopathological status, neurocognitive functioning and emotional recognition; WP2- stress response measured by saliva cortisol during a stress paradigm; cerebral blood perfusion in the resting state (with single photon emission computed tomography (SPECT) and during activation paradigm (with Transcranial Ultrasonography Doppler (TCD); WP3-post mortem analysis in histologically prepared human cortical tissue of post mortem samples of subjects with schizophrenia in the region that synaptic alteration was suggested by WP1 and WP2; WP4- pharmacogenetic analysis (single gene polymorphisms and genome wide association study (GWAS). We expect that the analysis of these data will identify a set of markers that differentiate healthy controls from patients with FEP, and serve as an additional diagnostic tool in the first episode of psychosis, and prediction tool which can be then used to help tailoring individualized treatment options. In this paper, we describe the project protocol including aims and methods and provide a brief description of planned post mortem studies and pharmacogenetic analysis.

Metabolomic Fingerprinting in Various Body Fluids of a Diet-Controlled Clinical Smoking Cessation Study Using a Validated GC-TOF-MS Metabolomics Platform.

Untargeted GC-TOF-MS analysis proved to be a suitable analytical platform to determine alterations in the metabolic profile. Several metabolic pathways were found to be altered in a first clinical study comparing smokers against nonsmokers. Subsequently, we conducted a clinical diet-controlled study to investigate alterations in the metabolic profile during the course of 3 months of smoking cessation. Sixty male subjects were included in the study, and plasma, saliva, and urine samples were collected during four 24 h stationary visits: at baseline, while still smoking, after 1 week, after 1 month, and after 3 months of cessation. Additionally, subjects were monitored for their compliance by measurements of CO in exhaled breath and salivary cotinine throughout the study. GC-TOF-MS fingerprinting was applied to plasma, saliva, and urine samples derived from 39 compliant subjects. In total, 52 metabolites were found to be significantly altered including 26 in plasma, 20 in saliva, and 12 in urine, respectively. In agreement with a previous study comparing smokers and nonsmokers, the fatty acid and amino acid metabolism showed significant alterations upon 3 months of smoking cessation. Thus these results may indicate a partial recovery of metabolic pathway perturbations, even after a relatively short period of smoking cessation.

Role of bone marrow-derived CD11c+ dendritic cells in systolic overload-induced left ventricular inflammation, fibrosis and hypertrophy.

Inflammatory responses play an important role in the development of left ventricular (LV) hypertrophy and dysfunction. Recent studies demonstrated that increased T-cell infiltration and T-cell activation contribute to LV hypertrophy and dysfunction. Dendritic cells (DCs) are professional antigen-presenting cells that orchestrate immune responses, especially by modulating T-cell function. In this study, we investigated the role of bone marrow-derived CD11c+ DCs in transverse aortic constriction (TAC)-induced LV fibrosis and hypertrophy in mice. We observed that TAC increased the number of CD11c+ cells and the percentage of CD11c+ MHCII+ (major histocompatibility complex class II molecule positive) DCs in the LV, spleen and peripheral blood in mice. Using bone marrow chimeras and an inducible CD11c+ DC ablation model, we found that depletion of bone marrow-derived CD11c+ DCs significantly attenuated LV fibrosis and hypertrophy in mice exposed to 24 weeks of moderate TAC. CD11c+ DC ablation significantly reduced TAC-induced myocardial inflammation as indicated by reduced myocardial CD45+ cells, CD11b+ cells, CD8+ T cells and activated effector CD8+CD44+ T cells in LV tissues. Moreover, pulsing of autologous DCs with LV homogenates from TAC mice promoted T-cell proliferation. These data indicate that bone marrow-derived CD11c+ DCs play a maladaptive role in hemodynamic overload-induced cardiac inflammation, hypertrophy and fibrosis through the presentation of cardiac self-antigens to T cells.