Mitigated viral myocarditis in A/J mice by the immunoproteasome inhibitor ONX 0914 depends on inhibition of systemic inflammatory responses in CoxsackievirusB3 infection

A preclinical model of troponin I-induced myocarditis (AM) revealed a prominent role of the immunoproteasome (ip), the main immune cell-resident proteasome isoform, in heart-directed autoimmunity. Viral infection of the heart is a known trigger of cardiac autoimmunity, with the ip enhancing systemic inflammatory responses after infection with a cardiotropic coxsackievirusB3 (CV). Here, we used ip-deficient A/J-LMP7(-/-) mice to investigate the role of ip-mediated effects on adaptive immunity in CV-triggered myocarditis and found no alteration of the inflammatory heart tissue damage or cardiac function in comparison to wild-type controls. Aiming to define the impact of the systemic inflammatory storm under the control of ip proteolysis during CV infection, we targeted the ip in A/J mice with the inhibitor ONX 0914 after the first cycle of infection, when systemic inflammation has set in, well before cardiac inflammation. During established acute myocarditis, the ONX 0914 treatment group had the same reduction in cardiac output as the controls, with inflammatory responses in heart tissue being unaffected by the compound. Based on these findings and with regard to the known anti-inflammatory role of ONX 0914 in CV infection, we conclude that the efficacy of ip inhibitors for CV-triggered myocarditis in A/J mice relies on their immunomodulatory effects on the systemic inflammatory reaction

Heart-specific immune responses in an animal model of autoimmune-related myocarditis mitigated by an immunoproteasome inhibitor and genetic ablation

BACKGROUND: Immune checkpoint inhibitor (ICI) therapy is often accompanied by immune-related pathology, with an increasing occurrence of high-risk ICI-related myocarditis. Understanding the mechanisms involved in this side effect could enable the development of management strategies. In mouse models, immune checkpoints, such as PD-1, control the threshold of self-antigen responses directed against cardiac troponin I (TnI). Here, we aimed at identifying how the immunoproteasome, the main proteolytic machinery in immune cells harboring three distinct protease activities in the LMP2, LMP7 and MECL1 subunit, affects TnI-directed autoimmune pathology of the heart. METHODS: TnI-directed autoimmune myocarditis (TnI-AM), a CD4(+) T cell-mediated disease, was induced in mice lacking all three immunoproteasome subunits, triple-ip(-/-), or lacking either the LMP2 or LMP7 gene, by immunization with a cardiac TnI peptide. Alternatively, prior to induction of TnI-AM or after establishment of AM, mice were treated with the immunoproteasome inhibitor ONX 0914. Immune parameters defining heart-specific autoimmunity were investigated in both experimental TnI-AM and in two cases of ICI-related myocarditis. RESULTS: All immunoproteasome-deficient strains showed mitigated autoimmune-related cardiac pathology with less inflammation, lower pro-inflammatory and chemotactic cytokines, less IL-17 production, and reduced fibrosis formation. Protection from TnI-directed autoimmune heart pathology with improved cardiac function in LMP7(-/-) mice involved a changed balance between effector and regulatory CD4(+) T cells in the spleen, with CD4(+) T cells from LMP7(-/-) mice showing a higher expression of inhibitory PD-1 molecules. Blocked immunoproteasome proteolysis, by treatment of TLR2 and TLR7/8-engaged CD14(+) monocytes with ONX 0914, diminished pro-inflammatory cytokine responses, thereby reducing the boost for the expansion of self-reactive CD4(+) T cells. Correspondingly, in mice, ONX 0914 treatment reversed cardiac autoimmune pathology, preventing both the induction and progression of TnI-AM, when self-reactive CD4+ T cells were primed. The autoimmune signature during experimental TnI-AM, with high immunoproteasome expression, immunoglobulinG deposition, IL-17 production in heart tissue and TnI-directed humoral autoimmune responses, was also present in two cases of ICI-related myocarditis, thus demonstrating the activation of heart-specific autoimmune reactions by ICI therapy. CONCLUSIONS: By reversing heart-specific autoimmune responses, immunoproteasome inhibitors applied to a mouse model demonstrate their potential to aid in the management of autoimmune myocarditis in humans, possibly including cases with ICI-related heart-specific autoimmunity

Science and technology roadmap for graphene, related two-dimensional crystals, and hybrid systems

We present the science and technology roadmap for graphene, related two-dimensional crystals, and hybrid systems, targeting an evolution in technology, that might lead to impacts and benefits reaching into most areas of society. This roadmap was developed within the framework of the European Graphene Flagship and outlines the main targets and research areas as best understood at the start of this ambitious project. We provide an overview of the key aspects of graphene and related materials (GRMs), ranging from fundamental research challenges to a variety of applications in a large number of sectors, highlighting the steps necessary to take GRMs from a state of raw potential to a point where they might revolutionize multiple industries. We also define an extensive list of acronyms in an effort to standardize the nomenclature in this emerging field