Cardiac myosin-Th17 responses promote heart failure in human myocarditis
Jennifer M. Myers, … , Carol J. Cox, Madeleine W. Cunningham
Jennifer M. Myers, … , Carol J. Cox, Madeleine W. Cunningham
Published June 16, 2016
Citation Information: JCI Insight. 2016;1(9):e85851. https://doi.org/10.1172/jci.insight.85851.
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Research Article Immunology

Cardiac myosin-Th17 responses promote heart failure in human myocarditis

Abstract

In human myocarditis and its sequela dilated cardiomyopathy (DCM), the mechanisms and immune phenotype governing disease and subsequent heart failure are not known. Here, we identified a Th17 cell immunophenotype of human myocarditis/DCM with elevated CD4+IL17+ T cells and Th17-promoting cytokines IL-6, TGF-β, and IL-23 as well as GM-CSF–secreting CD4+ T cells. The Th17 phenotype was linked with the effects of cardiac myosin on CD14+ monocytes, TLR2, and heart failure. Persistent heart failure was associated with high percentages of IL-17–producing T cells and IL-17–promoting cytokines, and the myocarditis/DCM phenotype included significantly low percentages of FOXP3+ Tregs, which may contribute to disease severity. We demonstrate a potentially novel mechanism in human myocarditis/DCM in which TLR2 peptide ligands from human cardiac myosin stimulated exaggerated Th17-related cytokines including TGF-β, IL-6, and IL-23 from myocarditic CD14+ monocytes in vitro, and an anti-TLR2 antibody abrogated the cytokine response. Our translational study explains how an immune phenotype may be initiated by cardiac myosin TLR ligand stimulation of monocytes to generate Th17-promoting cytokines and development of pathogenic Th17 cells in human myocarditis and heart failure, and provides a rationale for targeting IL-17A as a therapeutic option.

Authors

Jennifer M. Myers, Leslie T. Cooper, David C. Kem, Stavros Stavrakis, Stanley D. Kosanke, Ethan M. Shevach, DeLisa Fairweather, Julie A. Stoner, Carol J. Cox, Madeleine W. Cunningham

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Figure 6

Human cardiac myosin (HCM) is a major immune stimulator of myocarditis/dilated cardiomyopathy (DCM) CD14+ monocytes.

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Human cardiac myosin (HCM) is a major immune stimulator of myocarditis/d...
(A–D) Peripheral blood mononuclear cells (PBMCs) isolated from myocarditis/DCM subjects at baseline blood sample or from normal healthy individuals were cultured with HCM, HCM peptide S2-16, HCM peptide S2-28, or HCM peptides S2-16/S2-28 for 24 hours. After 24 hours, supernatants were collected and assayed by ELISA for TGF-β1, IL-6, IL-23, or IL-1β. P value indicates comparisons among myocarditis/DCM subjects and controls for 5 treatment conditions (media, +HCM, +S2-16, +S2-28, +S2-16/S2-28). (A) TGF-β1 production from CD14+ monocytes was significantly increased in myocarditis/DCM, as the TGF-β1 response to treatment with HCM TLR ligands differed between cases (n = 40) and controls (n = 16). Treatment by group interaction, repeated-measures ANOVA, P < 0.0001. (B) IL-6 production from CD14+ monocytes was significantly increased in myocarditis/DCM, as the IL-6 response to treatment differed between the cases (n = 33) and controls (n = 16). Treatment by group interaction, repeated-measures ANOVA, P = 0.0075. (C) IL-23 production from CD14+ monocytes was significantly increased in myocarditis/DCM, as the IL-23 response to treatment differed between cases (n = 11) and controls (n = 6). Treatment by group interaction, repeated-measures ANOVA, P < 0.0001. (D) IL-1β production from CD14+ monocytes was significantly increased in myocarditis/DCM, as the IL-1β response to treatment differed between cases (n = 34) and controls (n = 16). Treatment by group interaction, repeated-measures ANOVA, P = 0.0003. (E) Representative FACS analysis of PBMCs from myocarditis/DCM patients demonstrated that nearly 90% of cells producing TGF-β and IL-6 were CD14+ monocytes. FACS analysis was performed on fresh PBMCs, which were analyzed immediately upon receiving the blood sample. Only 1 sample per time point was analyzed by FACS and compared to isotype controls. Cytokine analysis was performed in triplicate to determine the cytokine concentration.