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

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.

scholarly journals CD11b+ Monocytes Abrogate Th17 CD4+ T Cell-Mediated Experimental Autoimmune Myocarditis

2008 ◽  
Vol 180 (4) ◽  
pp. 2686-2695 ◽  
Author(s):  
Alan Valaperti ◽  
René R. Marty ◽  
Gabriela Kania ◽  
Davide Germano ◽  
Nora Mauermann ◽  
...  
Keyword(s):  
T Cell ◽  
Cd4 T Cell ◽  
Autoimmune Myocarditis ◽  
Experimental Autoimmune Myocarditis ◽  
Experimental Autoimmune

scholarly journals Cardiosphere-Derived Cells Attenuate Inflammation, Preserve Systolic Function, and Prevent Adverse Remodeling in Rat Hearts With Experimental Autoimmune Myocarditis

2018 ◽  
Vol 24 (1) ◽  
pp. 70-77 ◽  
Author(s):  
E. Nana-Leventaki ◽  
M. Nana ◽  
N. Poulianitis ◽  
D. Sampaziotis ◽  
D. Perrea ◽  
...  
Keyword(s):  
T Cell ◽  
Systolic Function ◽  
Acute Myocarditis ◽  
Left Ventricular ◽  
Cell Infiltration ◽  
Myocardial Inflammation ◽  
Autoimmune Myocarditis ◽  
T Cell Infiltration ◽  
Experimental Autoimmune Myocarditis ◽  
Experimental Autoimmune

Background: Cardiosphere-derived cells (CDCs) have yielded promising efficacy signals in early-phase clinical trials of ischemic and nonischemic cardiomyopathy. The potential efficacy of CDCs in acute myocarditis, an inflammatory cardiomyopathy without effective therapy, remains unexplored. Given that CDCs produce regenerative, cardioprotective, anti-inflammatory, and anti-fibrotic effects (all of which could be beneficial in acute myocarditis), we investigated the efficacy of intracoronary delivery of CDCs in a rat model of experimental autoimmune myocarditis. Methods: Lewis rats underwent induction of experimental autoimmune myocarditis by subcutaneous footpad injection of purified porcine cardiac myosin supplemented with Mycobacterium tuberculosis on days 1 and 7. On day 10, rats were randomly assigned to receive global intracoronary delivery of 500 000 CDCs or vehicle. Global intracoronary delivery was performed by injection of cells or vehicle into the left ventricular (LV) cavity during transient occlusion of the aortic root. Rats were euthanized 18 days after infusion. Cardiac volumes and systolic function were assessed by serial echocardiography, performed on days 1, 10, and 28. Myocardial inflammation, T-cell infiltration, and cardiac fibrosis were evaluated by histology. Results: Experimental autoimmune myocarditis was successfully induced in 14/14 rats that completed follow-up. Left ventricular ejection fraction (LVEF) and volumes were comparable on days 1 and 10 between groups. CDC infusion resulted in increased LVEF (81.5% ± 3% vs 65.4% ± 8%, P < .001) and decreased LV end-systolic volume (43 ± 15 vs 100 ± 24 μL, P < .001) compared to placebo administration at 18 days post-infusion. Cardiosphere-derived cell infusion decreased myocardial inflammation (7.4% ± 7% vs 20.7% ± 4% of myocardium, P = .007), cardiac fibrosis (16.6% ± 13% vs 38.1% ± 3% of myocardium, P = .008), and myocardial T-cell infiltration (30.4 ± 29 vs 125.8 ± 49 cells per field, P = .005) at 18 days post-infusion compared to placebo administration. Conclusion: Intracoronary delivery of CDCs attenuates myocardial inflammation, T-cell infiltration, and fibrosis while preventing myocarditis-induced systolic dysfunction and adverse remodeling in rats with experimental autoimmune myocarditis.

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

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.

scholarly journals Effects of 1, 25-Dihydroxyvitamin D3 on Experimental Autoimmune Myocarditis in Mice

2016 ◽  
Vol 38 (6) ◽  
pp. 2219-2229 ◽  
Author(s):  
Fen Hu ◽  
Lianhua Yan ◽  
Shuai Lu ◽  
Wenhan Ma ◽  
Ya Wang ◽  
...  
Keyword(s):  
Beclin 1 ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Heart Weight ◽  
Autoimmune Myocarditis ◽  
Inflammatory Infiltration ◽  
Western Blots ◽  
Dihydroxyvitamin D3 ◽  
Multiple Systems ◽  
Experimental Autoimmune Myocarditis ◽  
Experimental Autoimmune

Background/Aims: Myocarditis is an important inflammatory disease of the heart which causes life-threatening conditions. 1, 25(OH)2 D3 has effects on multiple systems and diseases. The present study was aimed to investigate the effect of 1, 25(OH)2 D3 on experimental autoimmune myocarditis (EAM), and explored the underlying mechanisms involved. Methods: EAM was induced by immunizing BALB/c mice with cardiac α-myosin heavy chain peptides (MyHC-α). 1, 25(OH)2 D3 (1,000 ng/kg once) or vehicle was administered intraperitoneally every other day during the entire experiment. On day 21, transthoracic echocardiography was performed and cardiac inflammatory infiltration was detected by hematoxylin and eosin (HE). The terminal deoxynucleotidyl transferase mediated dUTP nick-end labeling (TUNEL) assay, and Western blots for the expression of protein caspase-3 and cleaved-caspase3 were used to evaluate apoptosis. Transmission electron microscopy and Western blots for the expression of protein Beclin-1, LC3B, and P62 were used to evaluate autophagy. Results: The ratio of heart weight/body weight was significantly reduced in 1, 25(OH)2 D3 -treated EAM mice, compared with vehicle -treated ones. 1, 25(OH)2 D3 treatment improved cardiac function, diminished cell infiltration in cardiac, suppressed myocardial apoptosis, decreased the number of autophagosomes, and decreased the protein expression of Beclin-1, LC3-II and p62. Conclusions: The present results demonstrated that administration of 1, 25(OH)2 D3 decreased EAM severity. 1, 25(OH)2 D3 treatment may be a feasible therapeutic approach for EAM.

scholarly journals RIP1/RIP3/MLKL Mediates Myocardial Function Through Necroptosis in Experimental Autoimmune Myocarditis

2021 ◽  
Vol 8 ◽  
Author(s):  
Yujing Wu ◽  
Zhenzhong Zheng ◽  
Xiantong Cao ◽  
Qing Yang ◽  
Vikram Norton ◽  
...  
Keyword(s):  
Cell Death ◽  
Myocardial Function ◽  
Viral Myocarditis ◽  
Cardiac Myosin ◽  
Autoimmune Myocarditis ◽  
Potential Therapeutic Target ◽  
Inflammatory Infiltration ◽  
Experimental Autoimmune Myocarditis ◽  
Experimental Autoimmune

Cardiomyopathy often leads to dilated cardiomyopathy (DCM) when caused by viral myocarditis. Apoptosis is long considered as the principal process of cell death in cardiomyocytes, but programmed necrosis or necroptosis is recently believed to play an important role in cardiomyocyte cell death. We investigated the role of necroptosis and its interdependency with other processes of cell death, autophagy, and apoptosis in a rat system of experimental autoimmune myocarditis (EAM). We successfully created a rat model system of EAM by injecting porcine cardiac myosin (PCM) and showed that in EAM, all three forms of cell death increase considerably, resulting in the deterioration of cardiac conditions with an increase in inflammatory infiltration in cardiomyocytes. To explore whether necroptosis occurs in EAM rats independent of autophagy, we treated EAM rats with a RIP1/RIP3/MLKL kinase-mediated necroptosis inhibitor, Necrostatin-1 (Nec-1). In Nec-1 treated rats, cell death proceeds through apoptosis but has no significant effect on autophagy. In contrast, autophagy inhibitor 3-Methyl Adenine (3-MA) increases necroptosis, implying that blockage of autophagy must be compensated through necroptosis. Caspase 8 inhibitor zVAD-fmk blocks apoptosis but increases both necroptosis and autophagy. However, all necroptosis, apoptosis, and autophagy inhibitors independently reduce inflammatory infiltration in cardiomyocytes and improve cardiac conditions. Since apoptosis or autophagy is involved in many important cellular aspects, instead of suppressing these two major cell death processes, Nec1 can be developed as a potential therapeutic target for inflammatory myocarditis.

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