Temporal change in Syndecan-1 as a therapeutic target and a biomarker for the severity classification of COVID-19.

BACKGROUND: Coronavirus disease 2019 (COVID-19) pneumonitis associated with severe respiratory failure is associated with high mortality. The pathogenesis of COVID-19 is associated with microembolism or microvascular endothelial injuries. Here, we report that syndecan-1 (SDC-1), a component of the endothelial glycocalyx, may be a biomarker of severity classification for COVID-19 related to endothelial injury. METHODS AND ANALYSIS: We analyzed the data of COVID-19 patients for 1 year from February 2020 at Yokohama City University Hospital and Yokohama City University Medical Center Hospital. We selected COVID-19 patients who required admission care, including intensive care, and analyzed the classification of severe and critical COVID-19 retrospectively, using various clinical data and laboratory data with SDC-1 by ELISA. RESULTS: We analyzed clinical and laboratory data with SDC-1 in five severe COVID-19 and ten critical COVID-19 patients. In the two groups, their backgrounds were almost the same. In laboratory data, the LDH, CHE, and CRP levels showed significant differences in each group (P = 0.032, P < 0.0001, and P = 0.007, respectively) with no significant differences in coagulation-related factors (platelet, PT-INR, d-dimer, ISTH score; P = 0.200, 0.277, 0.655, and 0.36, respectively). For the clinical data, the SOFA score was significantly different from admission day to day 14 of admission (p < 0.0001). The SDC-1 levels of critical COVID-19 patients were significantly higher on admission day and all-time course compared with the levels of severe COVID-19 patients (P = 0.009 and P < 0.0001, respectively). CONCLUSIONS: Temporal change of SDC-1 levels closely reflect the severity of COVID-19, therefore, SDC-1 may be a therapeutic target and a biomarker for the severity classification of Covid-19.

Time course of left ventricular reverse remodeling in response to pharmacotherapy: clinical implication for heart failure prognosis in patients with idiopathic dilated cardiomyopathy.

The present study aimed to identify the clinical significance of differences in detection timings of left ventricular reverse remodeling (LVRR) on heart failure (HF) prognosis in patients with idiopathic dilated cardiomyopathy (IDCM). We investigated 207 patients with IDCM who underwent pharmacotherapeutic treatment. LVRR was defined as improvements in both LV ejection fraction ≥10 % and indexed LV end-diastolic dimension (LVEDDi) ≥10 %. Patients were stratified into 3 groups by LVRR timing: patients with LVRR <24 months (Early LVRR), those with LVRR ≥24 months (Delayed LVRR), and those without LVRR during the entire follow-up period (No LVRR). The major endpoint was first detection of composite event including readmission for decompensated HF, major ventricular arrhythmias, or all-cause mortality. LVRR was recognized in 108 patients (52 %): Early LVRR in 83 (40 %), Delayed LVRR in 25 (12 %), and No LVRR in 99 (48 %). The survival rate for the major endpoint was significantly higher for Delayed LVRR than for No LVRR (P = 0.001); there was no significant difference between Early and Delayed LVRR. Among patients without LVRR <24 months (Delayed + No LVRR), receiver operating characteristic curve analysis showed that the area under the curve for improvement in LVEDDi during the first 6 months for predicting subsequent LVRR (Delayed LVRR) [0.822 (95 % confidence interval, 0.740-0.916; P = 0.038)] was greater than that for improvement in LVEF. In conclusion, LVRR was a favorable prognostic indicator in patients with IDCM irrespective of its detection timing. Reduced LVEDDi during the first 6 months was predictive for subsequent LVRR in the later phase.

Innate immune interleukin-1 receptor-associated kinase 4 exacerbates viral myocarditis by reducing CCR5(+) CD11b(+) monocyte migration and impairing interferon production.

BACKGROUND: Viral myocarditis follows a fatal course in ≈30% of patients. Interleukin-1 receptor-associated kinase 4 (IRAK4), a major nodal signal transducer in innate immunity, can play a pivotal role in host inflammatory response. We sought to determine how IRAK4 modulates inflammation and outcome in a mouse model of viral myocarditis. METHODS AND RESULTS: Myocarditis was induced after intraperitoneal inoculation of coxsackievirus B3 into C57Bl/6 IRAK4-deficient mice and their littermate controls. Mortality and viral proliferation were markedly reduced in IRAK4(-/-) mice compared with their IRAK4(+/+) littermates. Disease resistance of IRAK4(-/-) mice paralleled increased amounts of protective heart-infiltrating CCR5(+) monocytes/macrophages and enhanced interferon-α and interferon-γ production 2 days after infection. Competitive bone marrow chimera demonstrated that intact IRAK4 function inhibited heart-specific migration of bone marrow-derived CCR5(+) cells. Mechanistically, lack of IRAK4 resulted in interferon regulatory factor 5 homodimerization via reduced melanoma differentiation-associated protein 5 degradation and enhanced Stat1 and Stat5 phosphorylation. Consequently, antiviral interferon-α and interferon-γ production, as well as CCR5(+) cell recruitment, increased, whereas the overall proinflammatory response was drastically reduced in the absence of IRAK4. CONCLUSIONS: Innate immunity signal transducer IRAK4 exacerbates viral myocarditis through inhibition of interferon production and reduced mobilization of protective CCR5(+) monocytes/macrophages to the heart. The combination of IRAK4 inhibitors and antiviral adjuvants may become an attractive therapeutic approach against viral myocarditis in the future.

The adapter protein c-Cbl-associated protein (CAP) protects from acute CVB3-mediated myocarditis through stabilization of type I interferon production and reduced cytotoxicity.

c-Cbl-associated protein (CAP), also called Sorbs1 or ponsin, has been described as an essential adapter protein in the insulin-signalling pathway. Here, we describe for the first time a unique protective role for CAP in viral myocarditis. Mortality and heart failure development were increased in CAP(-/-) mice compared to CAP(+/+) littermates after Coxsackievirus (CVB3) infection. Mechanistically, CAP protected from tissue apoptosis because of reduced CD8(+) T and natural killer cell cytotoxicity. Despite reduced cytotoxic elimination of CVB3-infected cells in CAP(+/+) hearts, however, CAP enhanced interferon regulatory factor 3 (IRF3)-dependent antiviral type I interferon production and decreased viral proliferation in vitro by binding to the cytoplasmic RIG-I-like receptor melanoma differentiation-associated protein 5 (MDA5). Taken together, these findings reveal a novel modulatory role for CAP in the heart as a key protein stabilizing antiviral type I interferon production, while protecting from excessive cytotoxic responses. Our study will help to define future strategies to develop treatments to limit detrimental responses during viral heart inflammation.

Clinical significance of heart rate during acute decompensated heart failure to predict left ventricular reverse remodeling and prognosis in response to therapies in nonischemic dilated cardiomyopathy.

Although an increased heart rate (HR) is a strong predictor of poor prognosis in cases of chronic heart failure (HF), the clinical value of HR as a predictor in acute decompensated HF (ADHF) is unclear. Seventy-eight patients with nonischemic dilated cardiomyopathy (NIDCM) with sinus rhythm who were first hospitalized for ADHF from 2002 to 2010 were retrospectively investigated after exclusion of patients with tachycardia-induced cardiomyopathy. The patients were divided into two groups stratified by HR on admission with a median value of 113 beats/min (Group H with HR ≥ 113 beats/min; Group L with HR < 113 beats/min). Despite similar backgrounds, including pharmacotherapy for HF, HR changes responding to titration of ß-blocker (BB) therapy and myocardial interstitial fibrosis, left ventricular (LV) ejection fractions improved more significantly 1 year later in Group H than in Group L (57 % ± 11 % vs. 46 % ± 12 %, P < 0.001). Cardiac event-free survival rates were also significantly improved in Group H (P = 0.038). Multiple regression analysis revealed that only the peak HR on admission was an independent predictor of LV reverse remodeling (LVRR) 1 year later (ß = 0.396, P = 0.005). High HR on first admission for ADHF is a strong predictor of LVRR, with a better prognosis in the event of NIDCM in response to optimal pharmacotherapy, independent of pre-existing myocardial damage and subsequent HR reduction by BB therapy.

Baseline cardiac magnetic resonance imaging versus baseline endomyocardial biopsy for the prediction of left ventricular reverse remodeling and prognosis in response to therapy in patients with idiopathic dilated cardiomyopathy.

Endomyocardial biopsy (EMB) and late gadolinium enhancement cardiovascular magnetic resonance (LGE-CMR) imaging performed at baseline are both used to evaluate the extent of myocardial fibrosis. However, no study has directly compared the effectiveness of these diagnostic tools in the prediction of left ventricular reverse remodeling (LVRR) and prognosis in response to therapy in patients with idiopathic dilated cardiomyopathy (IDCM). Seventy-five patients with newly diagnosed IDCM who were undergoing optimal therapy were assessed at baseline using LGE-CMR imaging and EMB; the former measured LGE area and the latter measured collagen volume fraction (CVF) as possible predictive indices of LVRR and cardiac event-free survival. Among all the baseline primary candidate factors with P < 0.2 as per univariate analysis, multivariate analysis indicated that only LGE area was an independent predictor of subsequent LVRR (ß = 0.44; 95 % confidence interval (CI) 0.87-2.53; P < 0.001), as indicated by decreasing left ventricular end-systolic volume index over the 1-year follow-up. Kaplan-Meier curves indicated significantly lower cardiac event-free survival rates in patients with LGE at baseline than in patients without (P < 0.01). By contrast, there was no significant difference in prognosis between patients with CVF values above (severe fibrosis) and below (mild fibrosis) the median of 4.9 %. Cox proportional hazard analysis showed that LGE area was an independent predictor of subsequent cardiac events (hazard ratio 1.06; 95 % CI 1.02-1.10; P ≤ 0.01). The degree of myocardial fibrosis estimated by baseline LGE-CMR imaging, but not that estimated by baseline EMB, can predict LVRR and cardiac event-free survival in response to therapy in patients with newly diagnosed IDCM.

Therapeutic strategy using extracorporeal life support, including appropriate indication, management, limitation and timing of switch to ventricular assist device in patients with acute myocardial infarction.

The appropriate indication for, management of and limitations to extracorporeal life support (ECLS) and the timing of a switch to a ventricular assist device (VAD) remain controversial issues in patients with acute myocardial infarction (AMI) complicated with cardiogenic shock or cardiopulmonary arrest. To evaluate and discuss these issues, we studied patients with AMI treated with ECLS and compared deceased and discharged patients. Thirty-eight patients with AMI who needed ECLS [35 men (92.1 %), aged 59.9 ± 13.5 years] were enrolled in this study. Of these 38 patients, 34 subsequently underwent percutaneous coronary intervention (PCI), and four subsequently received coronary artery bypass grafting (CABG). Fourteen patients (36.8 %) were discharged from the hospital. The outcome was not favorable for those patients with deteriorating low output syndrome (LOS) and the development of leg ischemia, hemolysis and multiple organ failure during ECLS. Levels of creatine kinase, creatine kinase-MB (CK-MB), lactate dehydrogenase, serum creatinine (Cr) and amylase after the patient had been put on ECLS and fluctuation of the cardiac index, blood pressure, arterial blood gas analysis and CK-MB and Cr levels during ECLS were indicators to switch from the ECLS to VAD. In the case of patients with no complication associated with ECLS, 4.6-5.6 days after initiation of ECLS was assumed to be the threshold to decide whether to switch from ECLS to VAD. Patients with AMI who suddenly developed refractory pulseless ventricular tachycardia or ventricular fibrillation without deteriorating LOS and who underwent successful PCI or CABG, and who prevented the complications associated with ECLS, showed a high probability of recovering with ECLS.

Fibroblasts activation by embryonic signal switching: A novel mechanism of placental growth factor-induced cardiac remodeling.

INTRODUCTION: Cardiac remodeling is defined as cellular interstitial changes that lead dysfunction of the heart after injury. Placental growth factor (PlGF), a member of the VEGF family, has been reported to regulate cardiac hypertrophy in hemodynamic state. We therefore analyze the function of PlGF during cardiac remodeling using cardiac cells and fibroblasts, under Angiotensin II (AngII) stimulation. METHODS: PlGF overexpressed mouse embryonic fibroblasts derived from C57BL/6 mice, were made by deficient retrovirus vector, designated as C57/PlGF. Only retrovirus vector introduced C57 cells (C57/EV) were used as control. After AngII stimulation, wound scratching assay and MTT proliferation assay with or without p38 MAPK inhibitor, SB205580 were performed in retrovirally-introduced C57 cells. Reactive oxygen species (ROS) production, NF-kB activation, IL-6 and TNF-α production were also measured. Then we assessed AngII-induced cell proliferation of mouse cardiac fibroblasts (CFs) and rat primary cardiomyocytes incubating with C57/PlGF conditioned-medium. RESULTS: The PlGF production in C57/PlGF were confirmed by ELISA (1093.48 ± 3.5 pg/ml, ±SE). AngII-induced cell migration, proliferation and H2O2 production were increased in C57/PlGF compared with C57/EV. SB205580 inhibited the AngII-induced cell proliferation in C57/PlGF. In C57/PlGF cells, NF-kB activation was higher, followed by up-regulation of IL-6 and TNF-α production. CFs and cardiomyocytes proliferation increased when stimulated with C57/PlGF conditioned-medium. DISCUSSION: The activation of fibroblast is stimulated by PlGF signaling via p38 MAPK/NF-kB pathway accompanied by elevation of ROS and inflammatory response. Furthermore, these signals stimulate the activation of CFs and cardiomyocytes, indicating that high circulating level of PlGF have a potential to regulate cardiac remodeling.

Early alveolar epithelial cell necrosis is a potential driver of COVID-19-induced acute respiratory distress syndrome.

Acute respiratory distress syndrome (ARDS) with COVID-19 is aggravated by hyperinflammatory responses even after the peak of the viral load has passed; however, its underlying mechanisms remain unclear. In the present study, analysis of the alveolar tissue injury markers and epithelial cell death markers in patients with COVID-19 revealed that COVID-19-induced ARDS was characterized by alveolar epithelial necrosis at an early disease stage. Serum levels of HMGB-1, one of the DAMPs released from necrotic cells, were also significantly elevated in these patients. Further analysis using a mouse model mimicking COVID-19-induced ARDS showed that the alveolar epithelial cell necrosis involved two forms of programmed necrosis, namely necroptosis, and pyroptosis. Finally, the neutralization of HMGB-1 attenuated alveolar tissue injury in the mouse model. Collectively, necrosis, including necroptosis and pyroptosis, is the predominant form of alveolar epithelial cell death at an early disease stage and subsequent release of DAMPs is a potential driver of COVID-19-induced ARDS.

Combining blood glucose and SpO2/FiO2 ratio facilitates prediction of imminent ventilatory needs in emergency room COVID-19 patients.

The increasing requirement of mechanical ventilation (MV) due to the novel coronavirus disease (COVID-19) is still a global threat. The aim of this study is to identify markers that can easily stratify the impending use of MV in the emergency room (ER). A total of 106 patients with COVID-19 requiring oxygen support were enrolled. Fifty-nine patients were provided MV 0.5 h (interquartile range: 0.3 to 1.4) post-admission. Clinical and laboratory data before intubation were collected. Using a multivariate logistic regression model, we identified four markers associated with the impending use of MV, including the ratio of peripheral blood oxygen saturation to fraction of inspired oxygen (SpO2/FiO2 ratio), alanine aminotransferase, blood glucose (BG), and lymphocyte counts. Among these markers, SpO2/FiO2 ratio and BG, which can be measured easily and immediately, showed higher accuracy (AUC: 0.88) than SpO2/FiO2 ratio alone (AUC: 0.84), despite no significant difference (DeLong test: P = 0.591). Moreover, even in patients without severe respiratory failure (SpO2/FiO2 ratio > 300), BG (> 138 mg/dL) was predictive of MV use. Measuring BG and SpO2/FiO2 ratio may be a simple and versatile new strategy to accurately identify ER patients with COVID-19 at high risk for the imminent need of MV.

Prostaglandin-E2 receptor-4 stimulant rescues cardiac malfunction during myocarditis and protects the heart from adverse ventricular remodeling after myocarditis.

Cardioprotective effect of prostaglandin-E2 receptor-4 (EP4) stimulation on the ischemic heart has been demonstrated. Its effect on the heart affected by myocarditis, however, remains uncertain. In this study, we investigated therapeutic effect of EP4 stimulant using a mouse model of autoimmune myocarditis (EAM) that progresses to dilated cardiomyopathy (DCM). EP4 was present in the hearts of EAM mice. Treatment with EP4 agonist (ONO-0260164: 20 mg/kg/day) improved an impaired left ventricular (LV) contractility and reduction of blood pressure on day 21, a peak myocardial inflammation. Alternatively, DCM phenotype, characterized by LV dilation, LV systolic dysfunction, and collagen deposition, was observed on day 56, along with activation of matrix metalloproteinase (MMP)-2 critical for myocardial extracellular matrix disruption, indicating an important molecular mechanism underlying adverse ventricular remodeling after myocarditis. Continued treatment with ONO-0260164 alleviated the DCM phenotype, but this effect was counteracted by its combination with a EP4 antagonist. Moreover, ONO-0260164 inhibited in vivo proteolytic activity of MMP-2 in association with up-regulation of tissue inhibitor of metalloproteinase (TIMP)-3. EP4 stimulant may be a promising and novel therapeutic agent that rescues cardiac malfunction during myocarditis and prevents adverse ventricular remodeling after myocarditis by promoting the TIMP-3/MMP-2 axis.

Identification of serum prognostic biomarkers of severe COVID-19 using a quantitative proteomic approach.

The COVID-19 pandemic is an unprecedented threat to humanity that has provoked global health concerns. Since the etiopathogenesis of this illness is not fully characterized, the prognostic factors enabling treatment decisions have not been well documented. Accurately predicting the progression of the disease would aid in appropriate patient categorization and thus help determine the best treatment option. Here, we have introduced a proteomic approach utilizing data-independent acquisition mass spectrometry (DIA-MS) to identify the serum proteins that are closely associated with COVID-19 prognosis. Twenty-seven proteins were differentially expressed between severely ill COVID-19 patients with an adverse or favorable prognosis. Ingenuity Pathway Analysis revealed that 15 of the 27 proteins might be regulated by cytokine signaling relevant to interleukin (IL)-1ß, IL-6, and tumor necrosis factor (TNF), and their differential expression was implicated in the systemic inflammatory response and in cardiovascular disorders. We further evaluated practical predictors of the clinical prognosis of severe COVID-19 patients. Subsequent ELISA assays revealed that CHI3L1 and IGFALS may serve as highly sensitive prognostic markers. Our findings can help formulate a diagnostic approach for accurately identifying COVID-19 patients with severe disease and for providing appropriate treatment based on their predicted prognosis.

Combining IL-6 and SARS-CoV-2 RNAaemia-based risk stratification for fatal outcomes of COVID-19.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic rapidly increases the use of mechanical ventilation (MV). Such cases further require extracorporeal membrane oxygenation (ECMO) and have a high mortality. OBJECTIVE: We aimed to identify prognostic biomarkers pathophysiologically reflecting future deterioration of COVID-19. METHODS: Clinical, laboratory, and outcome data were collected from 102 patients with moderate to severe COVID-19. Interleukin (IL)-6 level and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA copy number in plasma were assessed with ELISA kit and quantitative PCR. RESULTS: Twelve patients died or required ECMO owing to acute respiratory distress syndrome despite the use of MV. Among various variables, a ratio of oxygen saturation to fraction of inspired oxygen (SpO2/FiO2), IL-6, and SARS-CoV-2 RNA on admission before intubation were strongly predictive of fatal outcomes after the MV use. Moreover, among these variables, combining SpO2/FiO2, IL-6, and SARS-CoV-2 RNA showed the highest accuracy (area under the curve: 0.934). In patients with low SpO2/FiO2 (< 261), fatal event-rate after the MV use at the 30-day was significantly higher in patients with high IL-6 (> 49 pg/mL) and SARS-CoV-2 RNAaemia (> 1.5 copies/µL) compared to those with high IL-6 or RNAaemia or without high IL-6 and RNAaemia (88% vs. 22% or 8%, log-rank test P = 0.0097 or P < 0.0001, respectively). CONCLUSIONS: Combining SpO2/FiO2 with high IL-6 and SARS-CoV-2 RNAaemia which reflect hyperinflammation and viral overload allows accurately and before intubation identifying COVID-19 patients at high risk for ECMO use or in-hospital death despite the use of MV.

Beta2-Adrenergic agonists suppress rat autoimmune myocarditis: potential role of beta2-adrenergic stimulants as new therapeutic agents for myocarditis.

BACKGROUND: The therapeutic potential of beta2-adrenergic receptor (AR) agonists in the treatment of autoimmune diseases has been reported. However, the role of these drugs in the myocardial structure-induced autoimmune process, which is thought to play a crucial role in the progression of myocarditis to subsequent complications, has not been elucidated. METHODS AND RESULTS: Experimental autoimmune myocarditis (EAM) was induced in rats by immunization with cardiac myosin. On daily administration from day 0 after immunization, the beta2-selective AR agonists formoterol or salbutamol ameliorated EAM on day 21 and increased myocardial interleukin-10/interferon-gamma mRNA levels. Propranolol, a nonselective beta-AR antagonist, aggravated EAM on day 21 and decreased mRNA levels, whereas metoprolol, a beta1-selective AR antagonist, showed no effect. These results were reflected in vivo by the proliferation of cardiac myosin-primed lymph node cells from drug-treated rats. In vitro addition of beta2-selective AR agonists inhibited the activation of cardiac myosin fragment-specific myocarditogenic T lymphocytes, and this effect was reversed by ICI118,551, a beta2-selective AR antagonist. Furthermore, treatment with 2 different beta2-selective AR agonists starting on day 14 also ameliorated EAM on day 21. CONCLUSIONS: beta2-AR stimulation suppressed the development of EAM by inhibiting cardiac myosin-specific T-lymphocyte activation in lymphoid organs and by shifting the imbalance in Th1/Th2 cytokine toward Th2 cytokine. Furthermore, it also ameliorated established myocardial inflammation. beta2-AR-stimulating agents may represent important immunomodulators of the cardiac myosin-induced autoimmune process and have potential as a new therapy for myocarditis.

Serum levels of interleukin-10 on admission as a prognostic predictor of human fulminant myocarditis.

OBJECTIVES: We assessed the significance of serum cytokine levels in patients with fulminant myocarditis. BACKGROUND: Although many investigations have demonstrated the crucial role of cytokines in the development of myocarditis, it remains uncertain whether serum levels of cytokines enable one to predict the prognosis of human myocarditis, especially concerning cardiogenic shock (CS) requiring a mechanical cardiopulmonary support system (MCSS). METHODS: We studied 22 consecutive patients with fulminant myocarditis and compared them with 15 patients with acute myocardial infarction (AMI) requiring MCSS. The patients with myocarditis were classified into three groups: eight patients with CS requiring MCSS on admission (group 1); six patients who unexpectedly lapsed into CS requiring MCSS more than two days after catecholamine had been initiated (group 2); and eight patients without MCSS (group 3). Furthermore, 14 patients with myocarditis requiring MCSS were divided into a fatal group (n = 5) and a survival group (n = 9). Biochemical markers, including serum cytokine levels and hemodynamic variables on admission, were analyzed. RESULTS: Serum levels of interleukin (IL)-10 and tumor necrosis factor-alpha, but not other cytokines, were significantly higher in myocarditis than in AMI. Only serum levels of IL-10 were significantly higher in group 1 and 2 than in group 3 (49.1 +/- 37.5/20.7 +/- 17.6 pg/ml vs. 2.4 +/- 1.1 pg/ml; p = 0.0008/0.0012). Serum IL-10 levels were also significantly higher in the fatal group than in the survival group with myocarditis (74.0 +/- 27.0 pg/ml vs. 16.4 +/- 8.8 pg/ml; p = 0.003). CONCLUSIONS: Serum IL-10 levels on admission enabled one to predict subsequent CS requiring MCSS and mortality of fulminant myocarditis patients.

Vaccination with Flt3L-induced CD8α+ dendritic cells prevents CD4+ T helper cell-mediated experimental autoimmune myocarditis.

Experimental autoimmune myocarditis (EAM) represents a CD4(+) T helper (Th) cell-mediated mouse model of inflammatory heart disease. Interferon (IFN)-γ, typically produced by Th1 cells, reduces EAM severity in myosin heavy-chain-(MyHC)-α peptide/Complete Freund adjuvant-immunized mice. Thus, developing a vaccination strategy that promotes differentiation of Th1 cells may be beneficial in EAM. FMS-like tyrosine kinase 3 ligand (Flt3L)-induced splenic CD8α(+) dendritic cells (DC), which produce interleukin (IL)-12p35, were identified to selectively induce biased differentiation towards Th1. Mice vaccinated with MyHC-α-loaded Flt3L-induced splenic CD8α(+) DC were protected from EAM. In contrast, when Flt3L-induced splenic CD8α(+) DC were pre-stimulated and over-activated with LPS and αCD40 antibodies or loaded with unspecific OVA(323-339) peptide instead of MyHC-α peptide, mice developed similar disease scores as non-vaccinated controls. Vaccination efficacy depended on IFN-γ, since CD8α(+)-vaccinated IFN-γR(-/-) mice were not protected. Importantly, splenic CD8α(+) vaccination was independent of regulatory T cells. Taken together, Flt3L-induced dendritic cell-based antigen-specific vaccination limits expansion of auto-reactive Th cells and protects mice from autoimmune heart inflammation.