Heart non-specific effector CD4+ T cells protect from postinflammatory fibrosis and cardiac dysfunction in experimental autoimmune myocarditis

AbstractHeart-specific CD4+ T cells have been implicated in development and progression of myocarditis in mice and in humans. Here, using mouse models of experimental autoimmune myocarditis (EAM) we investigated the role of heart non-specific CD4+ T cells in the progression of the disease. Heart non-specific CD4+ T cells were obtained from DO11.10 mice expressing transgenic T cell receptor recognizing chicken ovalbumin. We found that heart infiltrating CD4+ T cells expressed exclusively effector (Teff) phenotype in the EAM model and in hearts of patients with lymphocytic myocarditis. Adoptive transfer experiments showed that while heart-specific Teff infiltrated the heart shortly after injection, heart non-specific Teff effectively accumulated during myocarditis and became the major heart-infiltrating CD4+ T cell subset at later stage. Restimulation of co-cultured heart-specific and heart non-specific CD4+ T cells with alpha-myosin heavy chain antigen showed mainly Th1/Th17 response for heart-specific Teff and up-regulation of a distinct set of extracellular signalling molecules in heart non-specific Teff. Adoptive transfer of heart non-specific Teff in mice with myocarditis did not affect inflammation severity at the peak of disease, but protected the heart from adverse post-inflammatory fibrotic remodelling and cardiac dysfunction at later stages of disease. Furthermore, mouse and human Teff stimulated in vitro with common gamma cytokines suppressed expression of profibrotic genes, reduced amount of α-smooth muscle actin filaments and decreased contraction of cardiac fibroblasts. In this study, we provided a proof-of-concept that heart non-specific Teff cells could effectively contribute to myocarditis and protect the heart from the dilated cardiomyopathy outcome.

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Abstract 129: Suppressor of Cytokine Signaling 1 in Dendritic Cells Inhibits Myocardial Inflammation in Experimental Autoimmune Myocarditis

Circulation Research ◽

10.1161/res.111.suppl_1.a129 ◽

2012 ◽

Vol 111 (suppl_1) ◽

Author(s):

Kazuko Tajiri ◽

Kyoko Imanaka-Yoshida ◽

Michiaki Hiroe ◽

Nobutake Shimojo ◽

Satoshi Sakai ◽

...

Keyword(s):

T Cells ◽

Dendritic Cells ◽

T Cell ◽

Cd4 T Cells ◽

Cytokine Signaling ◽

Autoimmune Myocarditis ◽

Dc Function ◽

Autoreactive T Cell ◽

Experimental Autoimmune Myocarditis ◽

Experimental Autoimmune

Introduction: Autoimmunity is considered to play an important role in the development of myocarditis and dilated cardiomyopathy. Recent reports have indicated that a subgroup of myocarditis patients may benefit from immune-targeted therapies. Suppressor of cytokine signaling1 (SOCS1) is an intracellular, cytokine-inducible protein that regulates the responses of immune cells to cytokines. We therefore hypothesized that overexpression of SOCS1 may inhibit the inflammation of myocarditis and cardiomyopathy. Methods and Results: Myocarditis was induced by subcutaneous immunization with cardiac specific peptides derived from α-myosin heavy chain in BALB/c mice on days 0 and 7. Plasmid DNA encoding SOCS1 (pSOCS1) was injected intraperitoneally into mice on days 0, 5 and 10. pSOCS1 treatment significantly decreased heart-to-body weight ratios and the number of infiltrating cells in the heart. Echocardiography showed preserved contractile function in pSOCS1-treated mice. Although autoimmune myocarditis is a CD4+ T cell-mediated disease, pSOCS1 treatment does not have a direct suppressive effect on autoreactive T-cell activation. The introduced pSOCS1 suppressed proinflammatory cytokine production and STAT1 phosphorylation in dendritic cells (DCs). In addition, the proliferative responses of autoreactive CD4+ T cells co-cultured with DCs from pSOCS1-treated mice were much weaker than those of cells cultured with DCs from control plasmid-injected mice. These results suggested that the inoculated pSOCS1 may have been transfected into DCs and impaired DC function in vivo. Conclusion: The administration of pSOCS1 protected mice from the development of experimental autoimmune myocarditis, which was mediated by the inhibition of DC function that in turn reduced the activation of autoreactive CD4+ T cells.

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Treatment with N-acetyl-seryl-aspartyl-lysyl-proline prevents experimental autoimmune myocarditis in rats

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00300.2011 ◽

2012 ◽

Vol 303 (9) ◽

pp. H1114-H1127 ◽

Cited By ~ 20

Author(s):

Pablo Nakagawa ◽

Yunhe Liu ◽

Tang-Dong Liao ◽

Xiaojuan Chen ◽

Germán E. González ◽

...

Keyword(s):

T Cell ◽

Immune Responses ◽

Adhesion Molecules ◽

Cardiac Dysfunction ◽

Myocardial Injury ◽

Cardiac Myosin ◽

Autoimmune Myocarditis ◽

Cell Responses ◽

Experimental Autoimmune Myocarditis ◽

Experimental Autoimmune

Myocarditis is commonly associated with cardiotropic infections and has been linked to development of autoimmunity. N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP) is a naturally occurring tetrapeptide that prevents inflammation and fibrosis in hypertension and other cardiovascular diseases; however, its effect on autoimmune-mediated cardiac diseases remains unknown. We studied the effects of Ac-SDKP in experimental autoimmune myocarditis (EAM), a model of T cell-mediated autoimmune disease. This study was conducted to test the hypothesis that Ac-SDKP prevents autoimmune myocardial injury by modulating the immune responses. Lewis rats were immunized with porcine cardiac myosin and treated with Ac-SDKP or vehicle. In EAM, Ac-SDKP prevented both systolic and diastolic cardiac dysfunction, remodeling as shown by hypertrophy and fibrosis, and cell-mediated immune responses without affecting myosin-specific autoantibodies or antigen-specific T cell responses. In addition, Ac-SDKP reduced cardiac infiltration by macrophages, dendritic cells, and T cells, pro-inflammatory cytokines [interleukin (IL)-1α, tumor necrosis factor-α, IL-2, IL-17] and chemokines (cytokine-induced neutrophil chemoattractant-1, interferon-γ-induced protein 10), cell adhesion molecules (intercellular adhesion molecule-1, L-selectin), and matrix metalloproteinases (MMP). Ac-SDKP prevents autoimmune cardiac dysfunction and remodeling without reducing the production of autoantibodies or T cell responses to cardiac myosin. The protective effects of Ac-SDKP in autoimmune myocardial injury are most likely mediated by inhibition of 1) innate and adaptive immune cell infiltration and 2) expression of proinflammatory mediators such as cytokines, chemokines, adhesion molecules, and MMPs.

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Abstract 5261: Platelet-Depletion Ameliorates Cardiac Function and Disease Severity in Experimental Autoimmune Myocarditis

Circulation ◽

10.1161/circ.118.suppl_18.s_516-a ◽

2008 ◽

Vol 118 (suppl_18) ◽

Author(s):

Martin Russ ◽

Barbara Seliger ◽

Steffen Hauptmann ◽

Rene Marty ◽

Jürgen Bukur ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Cardiac Function ◽

Left Ventricular ◽

Inflammatory Cardiomyopathy ◽

Autoimmune Myocarditis ◽

Severity Scores ◽

Experimental Autoimmune Myocarditis ◽

Platelet Depletion ◽

Experimental Autoimmune

Introduction: Experimental Autoimmune Myocarditis (EAM) is a CD4+ T cell mediated model of inflammatory cardiomyopathy. Activated platelets express CD154, a molecule critical to adaptive immune responses, which has been implicated in platelet-mediated modulation of inflammation. Hypothesis: Platelets are critical for the generation of heart-specific, autoreactive T-cell responses in a model of experimental Autoimmune Myocarditis. Methods: BALB/c mice were immunized twice at day 0 and day 7 with 100μg alpha-MyHC-peptide (614–29) together with Complete Freund‘s adjuvant. Platelets were markedly depleted by i.v. injection of a GP1alpha antibody every 5th day (n=8). Control mice were injected with a non-depleting isotype antibody (n=8). Mice were assessed at day 28 for heart dimensions and cardiac function using echocardiography. After lethal anesthesia, hearts were removed and analyzed for heart weight/body weight ratio and histological severity scores. CD4+ T-cells were isolated from spleens, and analyzed for CD154 and IL-17 expression using FACS after in vitro re-stimulation on alpha-MyHC pulsed, irradiated antigen presenting cells. Results: Modest platelet depletion protected from left ventricular dilatation, and preserved left ventricular ejection fraction in immunized mice. Myocarditis prevalence and severity scores were significantly reduced in depleted animals. Relative numbers of spleen-derived CD4+ T-cells expressing CD154 or IL-17, were significantly reduced in the treatment group (table ). Conclusion: Our findings suggest that platelets might play a critical role in the development of heart-specific autoimmunity and cardiomyopathy. Further studies are needed to confirm these findings, which suggest a novel treatment approach for inflammatory cardiomyopathy. Echocardiography - Histology - FACS

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Programmed Death-Ligand 2 Deficiency Exacerbates Experimental Autoimmune Myocarditis in Mice

International Journal of Molecular Sciences ◽

10.3390/ijms22031426 ◽

2021 ◽

Vol 22 (3) ◽

pp. 1426

Author(s):

Siqi Li ◽

Kazuko Tajiri ◽

Nobuyuki Murakoshi ◽

DongZhu Xu ◽

Saori Yonebayashi ◽

...

Keyword(s):

T Cell ◽

Cell Receptor ◽

Cd4 T Cell ◽

Myocardial Inflammation ◽

Autoimmune Myocarditis ◽

Inflammatory Infiltration ◽

Programmed Death ◽

Experimental Autoimmune Myocarditis ◽

Deficient Mice ◽

Experimental Autoimmune

Programmed death ligand 2 (PD-L2) is the second ligand of programmed death 1 (PD-1) protein. In autoimmune myocarditis, the protective roles of PD-1 and its first ligand programmed death ligand 1 (PD-L1) have been well documented; however, the role of PD-L2 remains unknown. In this study, we report that PD-L2 deficiency exacerbates myocardial inflammation in mice with experimental autoimmune myocarditis (EAM). EAM was established in wild-type (WT) and PD-L2-deficient mice by immunization with murine cardiac myosin peptide. We found that PD-L2-deficient mice had more serious inflammatory infiltration in the heart and a significantly higher myocarditis severity score than WT mice. PD-L2-deficient dendritic cells (DCs) enhanced CD4+ T cell proliferation in the presence of T cell receptor and CD28 signaling. These data suggest that PD-L2 on DCs protects against autoreactive CD4+ T cell expansion and severe inflammation in mice with EAM.

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Abstract 14723: Autoreactive T Lymphocytes Activate Cardiac Endothelium Independently of Tnf-α and Cause Endothelial Dysfunction Through Exosomes in Experimental Autoimmune Myocarditis

Circulation ◽

10.1161/circ.142.suppl_3.14723 ◽

2020 ◽

Vol 142 (Suppl_3) ◽

Author(s):

Filip Rolski ◽

Marcin Czepiel ◽

Kazimierz Weglarczyk ◽

Maciej Siedlar ◽

Gabriela Kania ◽

...

Keyword(s):

T Cells ◽

Endothelial Dysfunction ◽

T Lymphocytes ◽

Conditioned Medium ◽

Autoimmune Myocarditis ◽

Autoreactive T Cells ◽

Tnf Α ◽

Experimental Autoimmune Myocarditis ◽

Experimental Autoimmune ◽

Stimulation Of

Background: Inflammatory heart diseases represent an important clinical problem, nonetheless data regarding activation of cardiac microvascular endothelial cells (MVECs) are limited. Aim: To examine influence of TNF-α and exosomes produced by heart-reactive CD4+ T lymphocytes on activation of cardiac MVECs. Methods: Experimental autoimmune myocarditis (EAM) was induced in wild-type (WT) and TNF-α-deficient (TNF-KO) mice. CD4+ T lymphocytes were isolated from EAM mice at day 21 and activated in vitro to produce conditioned medium and exosomes. Activation of MVECs was assessed by specific assays and leukocyte-to-endothelial adhesion was analysed under shear flow condition using the BioFlux microfluidic system. Results: TNF-KO mice showed lower prevalence of myocarditis when compared to WT mice (50% vs. 90%). Stimulation of MVECs with secretome of antigen-activated autoreactive T cells resulted in upregulation of adhesion molecules (ICAM-1, VCAM-1 and P-selectin), increased ROS and decreased NO production. Addition of anti-TNF-α neutralizing antibodies effectively blocked adhesion of leukocytes to MVECs activated with the conditioned medium. Endothelial activation and dysfunction induced by the conditioned medium were independent of TNF-α produced by T cells. Stimulation of MVECs with T cell-derived exosomes increased ROS and decreased levels of NO and eNOS activation, but exosomes neither increased expression of adhesion molecules in MVECs nor induced their ability to bind leukocytes. Conclusions: TNF-α promotes MVEC activation and EAM development. In this model, autoreactive T cells activate MVECs, and TNF-a produced by MVECs rather than T cells is essential in this process. On the other hand, endothelial dysfunction caused by T cells seems to be mediated mainly by exosomes.

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