T cells specific for α-myosin drive immunotherapy-related myocarditis

Functional diversity of cardiac macrophages in health and disease

Macrophages make up a substantial portion of the stromal compartment of the heart in health and disease. In the past decade, the origins of these cardiac macrophages have been established as two broad populations derived from either embryonic or definitive haematopoiesis and that can be distinguished by the expression of CC-motif chemokine receptor 2 (CCR2). These cardiac macrophage populations are transcriptionally distinct and have differing cell surface markers and divergent roles in cardiac homeostasis and disease. Embryonic-derived CCR2- macrophages are a tissue-resident population that participates in tissue development, repair and maintenance, whereas CCR2+ macrophages are derived from definitive haematopoiesis and contribute to inflammation and tissue damage. Studies from the past 5 years have leveraged single-cell RNA sequencing technologies to expand our understanding of cardiac macrophage diversity, particularly of the monocyte-derived macrophage populations that reside in the injured and diseased heart. Emerging technologies in spatial transcriptomics have enabled the identification of distinct disease-associated cellular neighbourhoods consisting of macrophages, other immune cells and fibroblasts, highlighting the involvement of macrophages in cell-cell communication. Together, these discoveries lend new insights into the role of specific macrophage populations in the pathogenesis of cardiac disease, which can pave the way for the identification of new therapeutic targets and the development of diagnostic tools. In this Review, we discuss the developmental origin of cardiac macrophages and describe newly identified cell states and associated cellular neighbourhoods in the steady state and injury settings. We also discuss various contributions and effector functions of cardiac macrophages in homeostasis and disease.

Immune checkpoint inhibitors: From friend to foe

Immune checkpoints are crucial in regulating the activation of cell-mediated and humoral immune responses. However, cancer cells hijack this mechanism to evade the immune surveillance and anti-cancer response. Typically, receptors like PD-1 and CTLA4, expressed on immune cells, prevent the activation and differentiation of T cells. They also inhibit the development of autoimmune reactions. However, ligands such as PD-L1 for the receptor PD-1 are also expressed on the surface of cancer cells that help prevent the activation of anti-cancer immune responses by blocking the signalling pathways mediated by PD-1 and CTLA4. Immune checkpoint inhibitors (ICIs) have promising therapeutic efficacy for treating several cancers by activating T cells and their differentiation into effector cells against tumours. Nonetheless, hyperactivated immune cells usually contribute to detrimental issues, also known as immune-related adverse effects (IrAE). IrAEs have been observed in multiple organs, leading to neurological issues, colitis, endocrine dysfunction, renal issues, hepatitis, pneumonitis, and dermatitis. The interplay between hyperactivated T cells and Treg cells helps in orchestrating the development of autoimmunity. Moreover, the crosstalk between proinflammatory interleukins and the development of autoantibodies also mediates the multiorgan effects of ICIs in cancer patients. IrAEs are generally managed by terminating the ICI therapy, reducing the ICI dose, and by using corticosteroids to subvert inflammation. Therefore, the present review aims to delineate the impacts of ICIs on the development of autoimmune diseases and inflammatory outcomes in cancer patients. In addition, mechanistic insight involving immune cells, cytokines, and autoantibodies for ICI-mediated IrAEs will also be discussed with updated findings in this field.

Single-cell transcriptomic analysis deciphers the inflammatory microenvironment characterized by CXCL9+ fibroblasts and ACKR1+ endothelial cells in immune-related myocarditis

BACKGROUND

Immune-related myocarditis induced by immune checkpoint inhibitors (ICIs) is a rare immune-related adverse event (irAE) but is characterized by a high mortality rate. However, the specific pathological mechanisms underlying immune-related myocarditis remain largely unclear. In this study, we aimed to elucidate the inflammatory microenvironment within cardiac tissues affected by immune-related myocarditis at the single-cell level to identify potential therapeutic targets.

METHODS

We performed single-cell RNA sequencing (scRNA-seq) on an endomyocardial biopsy specimen obtained from a patient with pancreatic neuroendocrine carcinoma who developed immune-related myocarditis following treatment with ICIs. Additionally, the scRNA-seq data of heart specimens from deceased donors without cardiovascular diseases were collected and applied as normal control. To validate our findings and assess their specificity to ICI-related pathology, we analyzed mouse scRNA-seq data, including controls, ICI-related myocarditis, viral myocarditis, and autoimmune myocarditis.

RESULTS

We found elevated proportions of lymphocytes, myeloid cells, and fibroblasts in the irAE group, suggesting an intensified inflammatory microenvironment in human immune-related myocarditis. Within the lymphocyte compartment, increased proportions of CD8 + T exhausted cells and CD8 + T proliferative cells were observed in the irAE group. The upregulated differentially expressed genes in myeloid cells in the irAE group were enriched in pro-inflammatory pathways, consistent with the observed metabolic shift from oxidative phosphorylation to glycolysis. CXCL9 + fibroblasts, characterized by the production of multiple pro-inflammatory cytokines and enriched in the JAK-STAT and TNFα signaling pathways, were predominantly found in the irAE group. Venous endothelial cells specifically expressing atypical chemokine receptor-1 (ACKR1) interacted with myeloid cells and CXCL9 + fibroblasts through the CXCL signaling pathway, facilitating chemokine transcytosis and leukocyte recruitment. Analysis of murine scRNA-seq data further supported these findings, revealing that exhausted CD8 + T cells and pro-inflammatory fibroblasts were uniquely enriched in ICI-related myocarditis, reflecting its distinct inflammatory microenvironment.

CONCLUSIONS

We elucidated the unique inflammatory microenvironment of immune-related myocarditis at the single-cell level. Our work revealed key cell subpopulations that were significantly implicated in inflammation, thus offering potential therapeutic targets.

Preclinical mouse models of immune checkpoint inhibitor-associated myocarditis

In this Review, we present a comprehensive analysis of preclinical models used to study immune checkpoint inhibitor-associated myocarditis (hereafter ICI-myocarditis), a potentially lethal immune-related adverse event. We begin by providing an overview of immune checkpoint inhibitors, highlighting how their efficacy in cancer treatment is counterbalanced by their predisposition to cause immune-related adverse events. Next, we draw from human data to identify disease features that an effective mouse model should ideally mimic. After that, we present a critical evaluation of a wide variety of existing mouse models including genetic, pharmacological and humanized models. We summarize insights gathered about the underlying mechanisms of ICI-myocarditis and the role of mouse models in these discoveries. We conclude with a perspective on the future of preclinical models, highlighting potential model improvements and research directions that could strengthen our understanding of ICI-myocarditis, ultimately improving patient outcomes.

The Cardiotoxicity Risk of Immune Checkpoint Inhibitors Compared with Chemotherapy: A Systematic Review and Meta-analysis of Observational Studies

Immune checkpoint inhibitors (ICIs) have demonstrated favorable outcomes in various cancers. However, it has been observed that ICIs may induce life-threatening cardiovascular toxicity. In this study, a meta-analysis was conducted to determine the risk of cardiovascular toxicities in patients exposed to ICIs or in combination with chemotherapy. PubMed, Cochrane Library, and Embase databases were searched from inception to September 24, 2023. This study was conducted in accordance with the PRISMA guidelines. A meta-analysis was conducted on the risk of cardiotoxicity in cancer patients. Data were pooled with a random-effect model. This protocol was registered prospectively in PROSPERO (CRD42023467319). The primary outcome was cardiotoxicity risk in observational studies with ICIs or combined with chemotherapy. The risk factors that affected the occurrence of cardiovascular toxicities were also examined. ICIs or combined with chemotherapy increased the cardiotoxicity risk compared with mono-chemotherapy (OR 1.47; 95% CI 1.05-2.06, p = 0.024). The risk of pericardial disease in cardiotoxic events (OR 1.99; 95% CI 1.23-3.22, p = 0.005) and thromboembolic events (OR 1.34; 95% CI 1.04-1.72, p = 0.025) was significantly increased. Smoking (OR 1.25; 95% CI 1.12-1.39, p < 0.001), previous heart disease (OR 2.01; 95% CI 1.64-2.46, p < 0.001), and lung cancer (OR 1.46; 95% CI 1.26-1.69, p < 0.001) were risk factors worthy of attention. ICIs or combined with chemotherapy show an elevated risk of cardiovascular toxicities. Patients who are smoking, diagnosed lung cancer, and having prior medical history of heart diseases need more attention.

Advances and applications in single-cell and spatial genomics

The applications of single-cell and spatial technologies in recent times have revolutionized the present understanding of cellular states and the cellular heterogeneity inherent in complex biological systems. These advancements offer unprecedented resolution in the examination of the functional genomics of individual cells and their spatial context within tissues. In this review, we have comprehensively discussed the historical development and recent progress in the field of single-cell and spatial genomics. We have reviewed the breakthroughs in single-cell multi-omics technologies, spatial genomics methods, and the computational strategies employed toward the analyses of single-cell atlas data. Furthermore, we have highlighted the advances made in constructing cellular atlases and their clinical applications, particularly in the context of disease. Finally, we have discussed the emerging trends, challenges, and opportunities in this rapidly evolving field.

ICI-induced cardiovascular toxicity: mechanisms and immune reprogramming therapeutic strategies

The advent of immune checkpoint inhibitors (ICIs) has revolutionized cancer treatment, offering life-saving benefits to tumor patients. However, the utilize of ICI agents is often accompanied by immune-related adverse events (irAEs), among which cardiovascular toxicities have attracted more and more attention. ICI induced cardiovascular toxicities predominantly present as acute myocarditis and chronic atherosclerosis, both of which are driven by excessive immune activation. Reprogramming of T cells and macrophages has been demonstrated as a pivotal factor in the pathogenesis of these complications. Therapeutic strategies targeting glycolysis, fatty acid oxidation, reactive oxygen species (ROS) production and some other key signaling have shown promise in mitigating immune hyperactivation and inflammation. In this review, we explored the intricate mechanisms underlying ICI-induced cardiovascular toxicities and highlighted the protective potential of immune reprogramming. We emphasize the roles of T cell and macrophage reprogramming in the heart and vasculature, showcasing their contributions to both short-term and long-term regulation of cardiovascular health. Ultimately, a deeper understanding of these processes will not only enhance the safety of ICIs but also pave the way for innovative strategies to manage immune-related toxicities in cancers therapy.

The pathogenesis of neurological immune-related adverse events following immune checkpoint inhibitor therapy

Cancer is a leading cause of morbidity and mortality worldwide. The development of immune checkpoint inhibitors (ICI) has revolutionised cancer therapy, and patients who were previously incurable can now have excellent responses. These therapies work by blocking inhibitory immune pathways, like cytotoxic T lymphocyte-associated protein 4 (CTLA-4), programmed cell death-1 (PD-1), its ligand PD-L1, and lymphocyte activation gene 3 (LAG-3); which leads to increased anti-tumour immune responses. However, their use can lead to the development of immune-related adverse events (irAEs), which may result in severe disability, interruption of cancer therapy, and even death. Neurological autoimmune sequelae occur in 1-10 % of patients treated with ICIs and can be fatal. They encompass a broad spectrum of diseases, may affect the central and the peripheral nervous system, and include syndromes like encephalitis, cerebellitis, neuropathy, and myositis. In some cases, neurological irAEs can be associated with autoantibodies recognising neuronal or glial targets. In this review, we first describe the key targets in ICI therapy, followed by a formulation of irAEs and their clinical presentations, where we focus on neurological syndromes. We comprehensively formulate the current literature evaluating cell surface and intracellular autoantibodies, cytokines, chemokines, leukocyte patterns, other blood derived biomarkers, and immunogenetic profiles; and highlight their impact on our understanding of the pathogenesis of neurological irAEs. Finally, we describe therapeutic pathways and patient outcomes, and provide an overview on future aspects of ICI cancer therapy.

Multimodal Imaging of Immune Checkpoint Inhibitor Myocarditis

Immune checkpoint inhibitors (ICIs) have dramatically changed the landscape of cancer treatment and are increasingly used either as monotherapy or in combination with other ICIs, chemotherapy, and molecularly targeted agents. ICI myocarditis is a rare but potentially fatal irAE associated with the use of ICI characterized by T-cell mediated cardiomyocyte death. Diagnosing ICI myocarditis can be intricate as its atypical presentations. Multimodal imaging plays a crucial role in the diagnosis and risk stratification of ICI myocarditis. Current management strategies for ICI myocarditis include corticosteroids and immunosuppressants. Multidisciplinary collaboration is vital in these cases-combining oncology expertise with cardiology insights.

MLKL-Mediated Necroptosis Predominantly Contributes to Immune-Associated Myocardial Damage

Activated T cells and macrophages play a critical role in immune-associated myocarditis. However, the molecular and cellular mechanisms driving cardiomyocyte damage by immune cells remain poorly understood. In this study, we co-cultured human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) with activated human peripheral blood mononuclear cells (aPBMCs) to recapitulate myocardial infiltration of immune cells. Our results demonstrated that aPBMCs induced hiPSC-CMs death in a dose- and time-dependent manner. Transcriptome analysis revealed the activation of several death pathways, including pyroptosis, apoptosis and necroptosis. The time course of immunofluorescence staining of key proteins related to different death pathways demonstrated that necroptosis was the earliest activated pathway. Pharmacological blockade of necroptosis by targeting mixed lineage kinase domain-like protein (MLKL), receptor-interacting protein kinase 1 (RIPK1) and receptor-interacting protein RIPK1 kinase 3 (RIPK3) protected hiPSC-CMs against injury induced by aPBMCs, while inhibitors of pyroptosis and apoptosis showed no protective effect. Moreover, MLKL knockdown in hiPSC-CMs prevented cell death due to aPBMCs challenge. Additionally, we validated the cardioprotective effects of blocking necroptosis in a mouse model of immune checkpoint inhibitors (ICIs)-related myocarditis using a combination of long-term anti-programmed cell death 1 (PD- 1) and anti-cytotoxic T-lymphocyte antigen- 4 (CTLA- 4) antibodies. ICIs led to elevation of myocardial injury markers in serum and activated immune cells infiltration. Furthermore, in vivo administration of a MLKL inhibitor prevented ICIs-induced myocardial injury. In conclusion, our findings suggested that MLKL-mediated necroptosis predominantly contributed to cardiomyocyte death resulting from activated immune cells. Suppressing necroptosis may be an effective therapeutic approach against myocardial damage in myocarditis.

CXCL12/CXCR4 axis mediates CD8 + T cell overactivation in the progression of viral myocarditis

BACKGROUND

Myocarditis is a common inflammatory heart disease in children and young adults, with fulminant myocarditis (FM) being the most severe form due to its rapid onset and high mortality rate. However, the precise pathological immune subsets and molecular change in myocarditis, particularly FM, remain unknown.

METHODS

We performed single-cell RNA sequencing of pediatric peripheral blood mononuclear cells during the acute and recovery phases of FM. A viral myocarditis (MC) mouse model was established using CVB3. Deletion and adoptive transfer of CD8+T cells, as well as blockade of CXCR4, were conducted in vivo. CD8+T cells were sorted and cultivated in vitro, then stimulated with CXCL12 and CXCR4 antagonists to investigate the mechanism of CD8+T cell overactivation.

RESULTS

CD8+T cells show significant activation, amplification, enhanced cytotoxicity, and increased chemotactic ability in FM. Deletion of CD8+T cells alleviates myocardial injury and improves cardiac function in MC mice, while adoptive transfer of CD8+T cells from MC mice aggravates myocardial inflammation and injury. The transcriptomic analysis reveals elevated CXCR4 expression in CD8+T cells in acute FM. In vitro experiments demonstrate that the CXCL12/CXCR4 axis drives the overactivation and cytotoxicity of CD8+T cells. In vivo treatment with a CXCR4 antagonist effectively reduces CD8+T cell accumulation in the heart, alleviates myocardial inflammation, and improves cardiac function in MC mice.

CONCLUSIONS

These findings provide deeper insights into the immune landscape of pediatric FM, uncovering a novel role of the CXCL12/CXCR4 axis in driving CD8+T cell responses in myocarditis. Furthermore, they highlight the CXCL12/CXCR4 axis as a promising therapeutic target for myocarditis treatment.

Artificial Intelligence to Enhance Precision Medicine in Cardio-Oncology: A Scientific Statement From the American Heart Association

Artificial intelligence is poised to transform cardio-oncology by enabling personalized care for patients with cancer, who are at a heightened risk of cardiovascular disease due to both the disease and its treatments. The rising prevalence of cancer and the availability of multiple new therapeutic options has resulted in improved survival among patients with cancer and has expanded the scope of cardio-oncology to not only short-term but also long-term cardiovascular risks resulting from both cancer and its treatments. However, there is considerable heterogeneity in cardiovascular risk, driven by the nature of the malignancy as well as each individual's unique characteristics. The use of novel therapies, such as targeted therapies and immune checkpoint inhibitors, across multiple cancer groups has also broadened the populations among which cardiotoxicity has become an important consideration of therapy. Therefore, the ability to understand and personalize cardiovascular risk management in patients with cancer is a key target for artificial intelligence, which can deduce and respond to complex patterns within the data. These advances necessitate an overview of established biomarkers of risk, spanning advanced imaging, diagnostic testing, and multi-omics, the evidence supporting their use, and the proven and proposed role of artificial intelligence in refining this risk to attain greater precision in risk prediction and management in cardio-oncologic care.

Immune checkpoint inhibitor-associated myocarditis: a historical and comprehensive review

The most fatal side effect associated with revolutionary immune checkpoint inhibitor (ICI) cancer therapies is myocarditis, a rare and devastating complication with a mortality rate approaching 40%. This review comprehensively examines the limited knowledge surrounding this recently recognized condition, emphasizing the absence of evidence-based therapeutic strategies, diagnostic modalities, and reliable biomarkers that hinder effective management. It explores advancements in preclinical models that are uncovering disease mechanisms and enabling the identification of therapeutic targets. These efforts have informed the design of early clinical trials aimed at reducing mortality. With the growing prevalence of ICI therapies in oncology, addressing critical gaps, such as long-term outcomes and risk stratification, has become increasingly urgent. By synthesizing current evidence, this work seeks to enhance understanding and guide the development of strategies to improve patient outcomes and ensure the continued safe use of ICIs in cancer care.

The immune checkpoint regulator CD40 potentiates myocardial inflammation

Immune checkpoint therapeutics including CD40 agonists have tremendous promise to elicit antitumor responses in patients resistant to current therapies. Conventional immune checkpoint inhibitors (PD-1, PD-L1 and CTLA-4 antagonists) are associated with serious adverse cardiac events including life-threatening myocarditis. However, little is known regarding the potential for CD40 agonists to trigger myocardial inflammation or myocarditis. Here we leverage genetic mouse models, single-cell sequencing and cell depletion studies to show that an anti-CD40 agonist antibody reshapes the cardiac immune landscape through activation of CCR2+ macrophages and subsequent recruitment of effector memory CD8+ T cells. We identify a positive feedback loop between CCR2+ macrophages (positive for the chemokine receptor CCR2) and CD8+ T cells driven by IL-12b, TNF and IFNγ signaling that promotes myocardial inflammation and show that previous exposure to CD40 agonists sensitizes the heart to secondary insults and accelerates left ventricular remodeling. Collectively, these findings highlight the potential for CD40 agonists to promote myocardial inflammation and potentiate heart failure pathogenesis.

High-throughput discovery of MHC class I- and II-restricted T cell epitopes using synthetic cellular circuits

Antigen discovery technologies have largely focused on major histocompatibility complex (MHC) class I-restricted human T cell receptors (TCRs), leaving methods for MHC class II-restricted and mouse TCR reactivities relatively undeveloped. Here we present TCR mapping of antigenic peptides (TCR-MAP), an antigen discovery method that uses a synthetic TCR-stimulated circuit in immortalized T cells to activate sortase-mediated tagging of engineered antigen-presenting cells (APCs) expressing processed peptides on MHCs. Live, tagged APCs can be directly purified for deconvolution by sequencing, enabling TCRs with unknown specificity to be queried against barcoded peptide libraries in a pooled screening context. TCR-MAP accurately captures self-reactivities or viral reactivities with high throughput and sensitivity for both MHC class I-restricted and class II-restricted TCRs. We elucidate problematic cross-reactivities of clinical TCRs targeting the cancer/testis melanoma-associated antigen A3 and discover targets of myocarditis-inciting autoreactive T cells in mice. TCR-MAP has the potential to accelerate T cell antigen discovery efforts in the context of cancer, infectious disease and autoimmunity.

Immune Checkpoint Inhibitor Myocarditis and Left Ventricular Systolic Dysfunction

BACKGROUND

Immune checkpoint inhibitors (ICIs) have transformed cancer treatment, but ICI myocarditis (ICI-M) remains a potentially fatal complication. The clinical implications and predictors of left ventricular ejection fraction (LVEF) <50% in ICI-M are not well understood.

OBJECTIVES

The aim of this study was to identify factors associated with LVEF <50% vs ≥50% at the time of hospitalization for ICI-M. A secondary objective was to evaluate the relationship between LVEF and 30-day all-cause mortality.

METHODS

The International ICI-Myocarditis Registry, a retrospective, international, multicenter database, included 757 patients hospitalized with ICI-M. Patients were stratified by LVEF as reduced LVEF (<50%) or preserved LVEF (≥50%) on admission. Cox proportional hazards models were used to assess the associations between LVEF and clinical events, and multivariable logistic regression was conducted to examine factors linked to LVEF.

RESULTS

Of 757 patients, 707 had documented LVEFs on admission: 244 (35%) with LVEF <50% and 463 (65%) with LVEF ≥50%. Compared with patients with LVEF ≥50%, those with LVEF <50% were younger (<70 years), had a body mass index of <25 kg/m2, and were more likely to have received chest radiation (24.2% vs 13.5%; P < 0.001). Multivariable analysis identified predictors of LVEF <50%, including exposure to v-raf murine sarcoma viral oncogene homolog B1/mitogen-activated protein kinase inhibitors, pre-existing heart failure, dyspnea at presentation, and at least 40 days from ICI initiation to ICI-M onset. Conversely, myositis symptoms were associated with LVEF ≥50%. LVEF <50% was marginally associated with 30-day all-cause mortality (unadjusted log-rank P = 0.062; adjusted for age, cancer types, and ICI therapy, HR: 1.50; 95% CI: 1.02-2.20).

CONCLUSIONS

Dyspnea, time from ICI initiation, a history of heart failure, and prior cardiotoxic therapy may be predictors of an initial LVEF <50% in patients with ICI-M.

Immune Checkpoint Inhibitor-Related Myocarditis With or Without Concomitant Myopathy: Clinical Findings and Cardiovascular Outcomes

BACKGROUND

Data on cardiovascular outcomes in patients with both immune checkpoint inhibitor-induced immune-related myocarditis (irMyocarditis) and immune-related myopathy (irMyopathy) are limited.

OBJECTIVES

The aim of this study was to describe clinical characteristics and cardiovascular outcomes in patients with isolated irMyocarditis vs those with concomitant irMyocarditis and irMyopathy.

METHODS

A retrospective cohort study was conducted among patients diagnosed with irMyocarditis at Massachusetts General Brigham between 2015 and 2023. Clinical, laboratory, and imaging characteristics were evaluated, and cardiovascular outcomes were compared between patients with and those without concomitant irMyopathy. The outcomes assessed included acute heart failure requiring diuresis, significant arrhythmias (ventricular arrhythmias and high-degree atrioventricular block), and cardiovascular and all-cause mortality during the index hospitalization.

RESULTS

Among 101 patients with irMyocarditis, 32 (31.7%) had concomitant irMyopathy. Patients with irMyocarditis and irMyopathy had higher high-sensitivity troponin T (median 716 ng/L vs 75 ng/L; P < 0.001) and creatine kinase levels (median 3441 U/L vs 232 U/L; P < 0.001) and were more likely to present with significant arrhythmias (HR: 2.12; 95% CI: 1.13-3.97; P = 0.019). Conversely, patients with isolated irMyocarditis had higher N-terminal prohormone of brain natriuretic peptide levels (median 2043 pg/mL vs 606 pg/mL; P = 0.007), lower left ventricular ejection fractions (median 56% vs 65%; P = 0.008), and a higher likelihood of acute decompensated heart failure (HR: 5.88; 95% CI: 1.45-25; P = 0.013). Cardiovascular and all-cause death during admission were numerically higher in patients with concomitant irMyopathy but were not significantly different between the 2 groups.

CONCLUSIONS

Patients with irMyocarditis and irMyopathy and those with isolated irMyocarditis have distinct biomarker profiles and cardiovascular complications. These differences should be confirmed in larger prospective cohorts to guide tailored management strategies.

Immune checkpoint inhibitors and myocarditis in advanced non-small cell lung cancer: a nationwide cohort study

OBJECTIVE

Evidence suggests immune checkpoint inhibitor (ICI) can increase the risk of myocarditis. We investigated it in a large national cohort in China.

METHODS

Patients with stage IIIB-IV non-small cell lung cancer (NSCLC) using data from China's National Anti-Tumor Drug Surveillance System between January 2013 and December 2021. Exposure density sampling was applied to control for immortal time bias. Multivariate Cox regression with time-dependent exposures was used to examine the association between ICI therapy and the incidence of myocarditis while controlling for confounders.

RESULTS

55,219 patients were included. The median age was 61 years, and 62% were males. At one-year follow-up (median 335 days), there were 26 cases of myocarditis among ICI users and 28 cases among ICI non-users (a cumulative incidence of 4.8 and 0.6 per 1000 person-years respectively). The adjusted hazard ratio (HR) of myocarditis for ICI users was 7.41 (95% confidence interval [CI]: 3.29-16.67). For programmed cell death protein 1 inhibitor users the HR was 8.39 (95% CI: 3.56-19.77). No significant interactions were observed in subgroup analysis. The results remained unchanged in sensitivity analyses.

CONCLUSIONS

This study showed that ICI therapy considerably increased the risk of myocarditis, supporting the need for closer monitoring of patients receiving ICI therapies.

From Bench to Bedside: Translational Approaches to Cardiotoxicity in Breast Cancer, Lung Cancer, and Lymphoma Therapies

Cardiotoxicity represents a critical challenge in cancer therapy, particularly in the treatment of thoracic tumors, such as lung cancer and lymphomas, as well as breast cancer. These malignancies stand out for their high prevalence and the widespread use of cardiotoxic treatments, such as chemotherapy, radiotherapy, and immunotherapy. This work underscores the importance of preclinical models in uncovering the mechanisms of cardiotoxicity and developing targeted prevention and mitigation strategies. In vitro models provide valuable insights into cellular processes, enabling the observation of changes in cell viability and function following exposure to various drugs or ionizing radiation. Complementarily, in vivo animal models offer a broader perspective, allowing for evaluating of both short- and long-term effects and a better understanding of chronic toxicity and cardiac diseases. By integrating these approaches, researchers can identify potential mechanisms of cardiotoxicity and devise effective prevention strategies. This analysis highlights the central role of preclinical models in advancing knowledge of cardiotoxic effects associated with common therapeutic regimens for thoracic and breast cancers.

Cardiac MRI study of adverse events in patients treated with immune checkpoint inhibitors: a prospective cohort study of cardiac adverse events

Immune checkpoint inhibitors (ICIs) revolutionized cancer therapy, yet require management of immune-related adverse events (irAEs). Fulminant myocarditis is a rare irAE, but lower-severity cardiac events are being reported more frequently, leading to an unmet need for irAE prevention, early diagnosis, and treatment, especially for long-life-expectancy patients. We recruited 57 patients, stratified according to therapy regime (monotherapy (30%) or combination (33%) cohort) or history of cardiac disease or presence of at least two cardiovascular risk factors other than prior or active smoking (cardiovascular cohort (37%)). We performed a complete cardiological assessment with clinical visit, 12-lead ECG, multiparametric cardiac MRI as well as peripheral blood mononuclear cell immunophenotyping, prior to ICI initiation and around 2 months later. ICI treatment was associated with a significant left ventricular ejection function (LVEF) reduction pre-ICI versus post-ICI treatment (60.1±8% to 58.1±8%, p=0.002, paired t-test) and more than 3% LVEF loss in a substantial proportion of patients (18; 32%). These patients also showed significantly higher T2 values (p=0.037, unpaired t-test), putative sign of cardiac edema. The loss of cardiac function did not differ among patients with different tumor types, therapy regimes or history of cardiac disease. Immunophenotyping analyses showed a reduction of programmed cell death protein 1 staining on both CD4+ and CD8+ T cells, and an upregulation of HLA-DR on CD8+ T cells. Using a very sensitive and comprehensive approach in patients unselected for cardiac history, we found a subclinical but significant LVEF decrease. These findings may inform ongoing discussions on optimal management of cardiac irAEs in patients undergoing ICI treatment and warrant further evaluation.

NI-3201 Is a Bispecific Antibody Mediating PD-L1-Dependent CD28 Co-stimulation on T Cells for Enhanced Tumor Control

Despite advances in cancer immunotherapy, such as targeting the PD-1/PD-L1 axis, a substantial number of patients harbor tumors that are resistant or relapse. Selective engagement of T-cell co-stimulatory molecules with bispecific antibodies may offer novel therapeutic options by enhancing signal 1-driven activation occurring via T-cell receptor engagement. In this study, we report the development and preclinical characterization of NI-3201, a PD-L1×CD28 bispecific antibody generated on the κλ-body platform that was designed to promote T-cell activity and antitumor function through a dual mechanism of action. We confirmed that NI-3201 blocks the PD-L1/PD-1 immune checkpoint pathway and conditionally provides T-cell co-stimulation via CD28 (signal 2) when engaging PD-L1+ tumors or immune cells. In systems with signal 1-primed T cells, NI-3201 enhanced potent effector functionality: in vitro through antigen-specific recall assays with cytomegalovirus-specific T cells and in vivo by inducing tumor regression and immunologic memory in tumor-associated antigen-expressing MC38 syngeneic mouse models. When T-cell engagers were used to provide synthetic signal 1, the combination with NI-3201 resulted in synergistic T cell-dependent cytotoxicity and potent antitumor activity in two humanized mouse tumor models. Nonhuman primate safety assessments showed favorable tolerability and pharmacokinetics at pharmacologically active doses. Quantitative systems pharmacology modeling predicted that NI-3201 exposure results in antitumor activity in patients, but this remains to be investigated. Overall, this study suggests that by combining PD-L1 blockade with safe and effective CD28 co-stimulation, NI-3201 has the potential to improve cancer immunotherapy outcomes, and the clinical development of NI-3201 for PD-L1+ solid tumors is planned.

Immune checkpoint inhibitors mediate myocarditis by promoting macrophage polarization via cGAS/STING pathway

BACKGROUND

Immune checkpoint inhibitors has opened up new avenues for cancer treatment, but serious cardiac injury has emerged in their use. A large number of data have shown that abnormal activation of cytosolic DNA-sensing cyclic GMP-AMP synthase-interferon gene activator pathway is closely related to cardiovascular inflammation and autoimmune diseases. However, the pathophysiological function of the cGAS-STING cascade in myocarditis induced by Immune checkpoint inhibitors is unclear.

METHODS

In order to establish a Immune checkpoint inhibitors-associated myocarditis model, BALB/c mice were injected with mouse cardiac troponin I peptide and anti-mouse programmed death 1 antibody. Echocardiography and HE staining were then performed to assess cardiac function and inflammation. Macrophages and damaged DNA in mouse heart tissue were detected by immunofluorescence. The mitochondrial damage of macrophages was observed by electron microscope. In vitro experiments, RAW264.7 was used to detect macrophage polarization after anti-PD-1 antibody induction and STING inhibition by qPCR and flow cytometry. Mitochondrial damage was detected by immunofluorescence, and activation of the cGAS-STING signaling pathway was evaluated by protein imprinting analysis.

RESULTS

In the Immune checkpoint inhibitors-associated myocarditis model, DNA damage was found to activate the cGAS-STING pathway and macrophages were polarized to M1 type. In vitro experiments, anti-PD-1 antibody activate the cGAS-STING pathway through the release of damaged DNA from macrophage mitochondrial damage, causing macrophage polarization into a pro-inflammatory phenotype leading to autoimmune myocarditis.

CONCLUSION

Our results suggested that the cGAS-STING pathway played a key role in myocarditis caused by immune checkpoint inhibitors. It provided a new possibility for Immune checkpoint inhibitors to be widely used in clinic.

Diagnosis of cancer therapy-related cardiovascular toxicities: A multimodality integrative approach and future developments

Diagnosing cancer therapy-related cardiovascular toxicities may be a challenge. The interplay between cancer and cardiovascular diseases, beyond shared cardiovascular and cancer risk factors, and the increasingly convoluted cancer therapy schemes have complicated cardio-oncology. Biomarkers used in cardio-oncology include serum, imaging and rhythm modalities to ensure proper diagnosis and prognostic stratification of cardiovascular toxicities. For now, troponin and natriuretic peptides, multimodal cardiovascular imaging (led by transthoracic echocardiography combined with cardiac magnetic resonance or computed tomography angiography) and electrocardiography (12-lead or Holter monitor) are cornerstones in cardio-oncology. However, the imputability of cancer therapies is sometimes difficult to assess, and more refined biomarkers are currently being studied to increase diagnostic accuracy. Advances reside partly in pathophysiology-based serum biomarkers, improved cardiovascular imaging through new technical developments and remote monitoring for rhythm disorders. A multiparametric omics approach, enhanced by deep-learning techniques, should open a new era for biomarkers in cardio-oncology in the years to come.

Novel Therapeutic Approach Targeting CXCR3 to Treat Immunotherapy Myocarditis

BACKGROUND

Immune checkpoint inhibitors (ICIs) are successful in treating many cancers but may cause immune-related adverse events. ICI-mediated myocarditis has a high fatality rate with severe cardiovascular consequences. Targeted therapies for ICI myocarditis are currently limited.

METHODS

We used a genetic mouse model of PD1 deletion (MRL/Pdcd1-/-) along with a novel drug-treated ICI myocarditis mouse model to recapitulate the disease phenotype. We performed single-cell RNA-sequencing, single-cell T-cell receptor sequencing, and cellular indexing of transcriptomes and epitopes on immune cells isolated from MRL and MRL/Pdcd1-/- mice at serial time points. We assessed the impact of macrophage deletion in MRL/Pdcd1-/- mice, then inhibited CXCR3 (C-X-C motif chemokine receptor 3) in ICI-treated mice to assess the therapeutic effect on myocarditis phenotype. Furthermore, we delineated the functional and mechanistic effects of CXCR3 blockade on T-cell and macrophage interactions. We then correlated the results in human single-cell multiomics data from blood and heart biopsy data from patients with ICI myocarditis.

RESULTS

Single-cell multiomics demonstrated expansion of CXCL (C-X-C motif chemokine ligand) 9/10+CCR2+ macrophages and CXCR3hi (C-X-C motif chemokine receptor 3 high-expressing) CD8+ (cluster of differentiation) effector T lymphocytes in the hearts of MRL/Pdcd1-/- mice correlating with onset of myocarditis development. Both depletion of CXCL9/10+CCR2+ (C-C motif chemokine receptor) macrophages and CXCR3 blockade, respectively, led to decreased CXCR3hi CD8+ T-cell infiltration into the heart and significantly improved survival. Transwell migration assays demonstrated that the selective blockade of CXCR3 and its ligand, CXCL10, reduced CXCR3+CD8+ T-cell migration toward macrophages, implicating this interaction in T-cell cardiotropism toward cardiac macrophages. Furthermore, cardiomyocyte apoptosis was induced by CXCR3hi CD8+ T cells. Cardiac biopsies from patients with confirmed ICI myocarditis demonstrated infiltrating CXCR3+ T cells and CXCL9+/CXCL10+ macrophages. Both mouse cardiac immune cells and patient peripheral blood immune cells revealed expanded TCRs (T-cell receptors) correlating with CXCR3hi CD8+ T cells in ICI myocarditis samples.

CONCLUSIONS

These findings bring forth the CXCR3-CXCL9/10 axis as an attractive therapeutic target for ICI myocarditis treatment, and more broadly as a druggable pathway in cardiac inflammation.

Spatiotemporal transcriptomics elucidates the pathogenesis of fulminant viral myocarditis

Fulminant myocarditis (FM) is a severe inflammatory condition of the myocardium that often results in sudden death, particularly in young individuals. In this study, we employed single-nucleus and spatial transcriptomics to perform a comprehensive analysis of coxsackievirus B3 (CVB3)-induced FM in A/J mice, spanning seven distinct time points pre- and post-treatment. Our findings reveal that mesothelial cells play a critical role in the early stage of myocarditis by acting as primary targets for CVB3 infection. This triggers the activation of macrophages, initiating a cascade of inflammation. Subsequently, pro-inflammatory Inflammatory_Mac and T cells infiltrate the myocardium, driving tissue damage. We also identified Cd8+ effector T cells as key mediators of cardiomyocyte injury. These cells release cytotoxic molecules, particularly IFN-γ, which modulates the expression of Spi1, a factor implicated in exacerbating cardiomyocyte death and amplifying disease progression. Therapeutic interventions targeting the IFN-γ/Spi1 axis demonstrated significant efficacy in FM models. Notably, intravenous immunoglobulin (IVIG) treatment reduced mortality, suppressed viral proliferation, and mitigated the hyperinflammatory state of FM. IVIG therapy also downregulated IFN-γ and Spi1 expression, underscoring its immunomodulatory and therapeutic potential. This comprehensive spatiotemporal transcriptomic analysis provides profound insights into the pathogenesis of FM and highlights actionable therapeutic targets, paving the way for more effective management strategies for this life-threatening condition.

Evaluation of patient immunocompetence for immune checkpoint inhibitor therapy using the psoas muscle index: a retrospective cohort study

Introduction

In patients with cancer, sarcopenia is an indicator of poor prognosis and is associated with an increased risk of chemotherapy-related adverse events. Skeletal muscle interacts with the immune system, and sarcopenia is associated with immune senescence. However, the association between sarcopenia and the response to immune checkpoint inhibitor (ICI) therapy remains unclear.

Methods

This retrospective study included patients with advanced or recurrent non-small cell lung cancer treated with nivolumab or pembrolizumab monotherapy. The association between the psoas muscle index (PMI) and both clinical response and immune-related adverse events (irAEs) was assessed using logistic regression. The PMI was calculated as the cross-sectional area of the psoas muscle divided by the square of the height based on computed tomography scans performed before the initial administration of ICI therapy.

Results

A total of 67 patients were included in the analysis. Logistic regression analysis showed that PMI was associated with the overall response (odds ratio [OR]: 1.52; 95% confidence interval [CI]: 1.04-2.22; p = 0.030) and the risk of severe irAEs (OR: 1.72; 95% CI: 1.05-2.80; p = 0.031).

Conclusion

These findings suggest that PMI is both an indicator of prognosis and a surrogate marker of immunocompetence in predicting the clinical response to ICI therapy.

Preclinical models of cardiotoxicity from immune checkpoint inhibitor therapy

Immune checkpoint inhibitor (ICI) therapy represents a ground-breaking paradigm in cancer treatment, harnessing the immune system to combat malignancies by targeting checkpoints such as cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and programmed cell death protein 1 (PD-1). The use of ICI therapy generates distinctive immune-related adverse events (irAEs) including cardiovascular toxicity, necessitating targeted research efforts. This comprehensive review explores preclinical models dedicated to ICI-mediated cardiovascular complications including myocarditis. Tailored preclinical models of ICI-mediated myocardial toxicities highlight the key role of CD8+ T cells, emphasizing the profound impact of immune checkpoints on maintaining cardiac integrity. Cytokines and macrophages were identified as possible driving factors in disease progression, and at the same time, initial data on possible cardiac antigens responsible are emerging. The implications of contributing factors including thoracic radiation, autoimmune disorder, and the presence of cancer itself are increasingly understood. Besides myocarditis, mouse models unveiled an accelerated progression of atherosclerosis, adding another layer for a thorough understanding of the diverse processes involving cardiovascular immune checkpoint signalling. This review aims to discuss current preclinical models of ICI cardiotoxicity and their potential for improving enhanced risk assessment and diagnostics, offering potential targets for innovative cardioprotective strategies. Lessons from ICI therapy can drive novel approaches in cardiovascular research, extending insights to areas such as myocardial infarction and heart failure.

The cardio-oncologic burden of breast cancer: molecular mechanisms and importance of preclinical models

Breast cancer, the most prevalent cancer affecting women worldwide, poses a significant cardio-oncological burden. Despite advancements in novel therapeutic strategies, anthracyclines, HER2 antagonists, and radiation remain the cornerstones of oncological treatment. However, each carries a risk of cardiotoxicity, though the molecular mechanisms underlying these adverse effects differ. Common mechanisms include DNA damage response, increased reactive oxygen species, and mitochondrial dysfunction, which are key areas of ongoing research for potential cardioprotective strategies. Since these mechanisms are also essential for effective tumor cytotoxicity, we explore tumor-specific effects, particularly in hereditary breast cancer linked to BRCA1 and BRCA2 mutations. These genetic variants impair DNA repair mechanisms, increase the risk of tumorigenesis and possibly for cardiotoxicity from treatments such as anthracyclines and HER2 antagonists. Novel therapies, including immune checkpoint inhibitors, are used in the clinic for triple-negative breast cancer and improve the oncological outcomes of breast cancer patients. This review discusses the molecular mechanisms underlying BRCA dysfunction and the associated pathological pathways. It gives an overview of preclinical models of breast cancer, such as genetically engineered mouse models, syngeneic murine models, humanized mouse models, and various in vitro and ex vivo systems and models to study cardiovascular side effects of breast cancer therapies. Understanding the underlying mechanism of cardiotoxicity and developing cardioprotective strategies in preclinical models are essential for improving treatment outcomes and reducing long-term cardiovascular risks in breast cancer patients.

Molecular fingerprints of cardiovascular toxicities of immune checkpoint inhibitors

Immune checkpoint inhibitors (ICIs) have revolutionized cancer therapy by unleashing the power of the immune system against malignant cells. However, their use is associated with a spectrum of adverse effects, including cardiovascular complications, which can pose significant clinical challenges. Several mechanisms contribute to cardiovascular toxicity associated with ICIs. First, the dysregulation of immune checkpoints, such as cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and programmed cell death protein-1 (PD-1) and its ligand (PD-L1), and molecular mimicry with cardiac autoantigens, leads to immune-related adverse events, including myocarditis and vasculitis. These events result from the aberrant activation of T cells against self-antigens within the myocardium or vascular endothelium. Second, the disruption of immune homeostasis by ICIs can lead to autoimmune-mediated inflammation of cardiac tissues, manifesting as cardiac dysfunction and heart failure, arrhythmias, or pericarditis. Furthermore, the upregulation of inflammatory cytokines, particularly tumor necrosis factor-alpha, interferon-γ, interleukin-1β, interleukin-6, and interleukin-17 contributes to cardiac and endothelial dysfunction, plaque destabilization, and thrombosis, exacerbating cardiovascular risk on the long term. Understanding the intricate mechanisms of cardiovascular side effects induced by ICIs is crucial for optimizing patient care and to ensure the safe and effective integration of immunotherapy into a broader range of cancer treatment protocols. The clinical implications of these mechanisms underscore the importance of vigilant monitoring and early detection of cardiovascular toxicity in patients receiving ICIs. Future use of these key pathological mediators as biomarkers may aid in prompt diagnosis of cardiotoxicity and will allow timely interventions.

4E-BP3 deficiency impairs dendritic cell activation and CD4+ T cell differentiation and attenuates α-myosin-specific T cell-mediated myocarditis in mice

Immune checkpoint inhibitor (ICI)-associated myocarditis is a rare but potentially fatal immune-related adverse event. Previously, we reported a case of ICI-associated myocarditis with elevated autoantibodies to 4E-binding protein 3 (4E-BP3). Recent studies have suggested that 4E-BP3 may play an important role in tumor development. However, its role in cardiac diseases including myocarditis is unknown. We investigated the role of 4E-BP3 in an autoimmune myocarditis mouse model. Myocarditis was induced in wild-type and 4E-BP3 knockout mice by immunization with murine α-myosin peptide. 4E-BP3 gene expression was upregulated in the heart of myocarditis mouse. We found that genetic deletion of 4E-BP3 attenuated myocardial inflammation, reduced fibrosis area, and improved cardiac function in myocarditis mice. Studies in bone marrow-chimeric mice demonstrated that immune cell-derived 4E-BP3 plays a pivotal role in the pathogenesis of myocarditis. Immune cell transfer experiments revealed that 4E-BP3 deficiency in dendritic cells and CD4+ T cells decreased disease severity in recipient mice. Furthermore, dendritic cells that were deficient in 4E-BP3 exhibited a diminished capacity to produce IL-6 and IL-1β. Naive CD4+ T cells lacking 4E-BP3 had a reduced ability to differentiate into T-helper (Th)1 and Th17 cells. These findings suggest that 4E-BP3 in dendritic cells and CD4+ T cells may be critically involved in the pathogenesis of α-myosin-specific T cell-mediated myocarditis. Thus, 4E-BP3 could be a possible therapeutic target for myocarditis.

Abatacept dose-finding phase II triaL for immune checkpoint inhibitors myocarditis (ACHLYS) trial design

BACKGROUND

Immune checkpoint inhibitor (ICI)-induced myocarditis is a life-threatening adverse drug reaction. Abatacept (a CTLA-4-immunoglobulin fusion protein) has been proposed as a compassionate-use treatment for ICI myocarditis (in combination with corticosteroids and ruxolitinib) but no clinical trial has yet been performed. The abatacept dose can be adjusted using real-time assessment of its target, the CD86 receptor occupancy on circulating monocytes (CD86RO).

METHODS

The ACHLYS trial is an ongoing dose-finding, Phase II, randomized, double-blind trial in which three different abatacept doses are being tested, aiming to reach CD86RO≥80% after the first dose and sustainably during the first 3 weeks of ICI myocarditis treatment (primary outcome). Adult patients with cancer presenting severe or corticosteroid-resistant ICI myocarditis have been included. ICI are withheld after inclusion and for the study duration. Abatacept is administered by intravenous injection on Days 1, 5±2 and 14±2 at 10, 20 or 25mg/kg depending on the randomization arm (n=7 per arm) with concomitant ruxolitinib and corticosteroids. After evaluation of the primary outcome on Day 21, complementary injections of abatacept (for≤3 months) and a ruxolitinib/corticosteroids weaning strategy are standardized depending on criteria evaluating resolution of ICI myocarditis severity (troponin T level and clinical assessment). Secondary objectives compare immunological, myocardial and muscular proxies of treatment response between randomization arms, and cancer progression-free and overall survivals up to 1 year.

CONCLUSION

The ACHLYS trial will define the most appropriate starting dose of abatacept to treat life-threatening ICI myocarditis, in combination with ruxolitinib and corticosteroids.

CLINICALTRIALS

GOV: NCT05195645.

Cardiac Complications of Immune Checkpoint Inhibitors and Chimeric Antigen Receptor T Cell Therapy

Immune checkpoint inhibitors and chimeric antigen receptor T-cell therapy have revolutionized cancer treatment but can cause life-threatening cardiovascular toxicities through immune-related adverse events. Myocarditis is the most common and potentially fatal toxicity with immune checkpoint inhibitors. T-cell therapies can potentially lead to cytokine release syndrome. Diagnosis of ICI-myocarditis requires a multimodal approach, including biomarkers, imaging, and endomyocardial biopsy, while CRS is characterized by a clinical syndrome resembling distributive shock. Management involves discontinuing the offending therapy, immunosuppression with corticosteroids for ICI-myocarditis, and interleukin-6 antagonists for CRS. Collaboration between oncologists and cardiologists is crucial for early recognition and prompt treatment.

Immuno-related cardio-vascular adverse events associated with immuno-oncological treatments: an under-estimated threat for cancer patients

Immunotherapy represents an emergent and heterogeneous group of anticancer treatments harnessing the human immune-surveillance system, including immune-checkpoint inhibitor monoclonal antibodies (mAbs), Chimeric Antigen Receptor T Cells (CAR-T) therapy, cancer vaccines and lymphocyte activation gene-3 (LAG-3) therapy. While remarkably effective against several malignancies, these therapies, often in combination with other cancer treatments, have showed unforeseen toxicity, including cardiovascular complications. The occurrence of immuno-mediated adverse (irAEs) events has been progressively reported in the last 10 years. These irAEs present an extended range of severity, from self-limiting to life-threatening conditions. Although recent guidelines in CardioOncology have provided important evidence in managing cancer treatments, they often encompass general approaches. However, a specific focus is required due to the particular etiology, unique risk factors, and associated side effects of immunotherapy. This review aims to deepen the understanding of the prevalence and nature of cardiovascular issues in patients undergoing immunotherapy, offering insights into strategies for risk stratification and management.

T cells in cardiac health and disease

Cardiovascular disease (CVD) remains the leading cause of morbidity and mortality worldwide, with inflammation playing a pivotal role in its pathogenesis. T lymphocytes are crucial components of the adaptive immune system that have emerged as key mediators in both cardiac health and the development and progression of CVD. This Review explores the diverse roles of T cell subsets, including Th1, Th17, γδ T cells, and Tregs, in myocardial inflammatory processes such as autoimmune myocarditis and myocardial infarction. We discuss the contribution of T cells to myocardial injury and remodeling, with emphasis on specific immune receptors, e.g., CD69, that have a critical role in regulating immune tolerance and maintaining the balance between T cell subsets in the heart. Additionally, we offer a perspective on recent advances in T cell-targeted therapies and their potential to modulate immune responses and improve clinical outcomes in patients with CVD and in heart transplant recipients. Understanding the intricate interplay between T cells and cardiovascular pathology is essential for developing novel immunotherapeutic strategies against CVD.

Targeting the NLRP3 inflammasome abrogates cardiotoxicity of immune checkpoint blockers

BACKGROUND

Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of many malignant tumors. However, ICI-induced hyper-immune activation causes cardiotoxicity. Traditional treatments such as glucocorticoids and immunosuppressants have limited effectiveness and may even accelerate tumor growth. This study aimed to identify approaches that effectively reduce cardiotoxicity and simultaneously preserve or enhance the antitumor immunity of ICI therapy.

METHODS

ICI injection in melanoma-bearing C57BL/6J female mice was used to simulate cardiotoxicity in patients with tumor undergoing immune therapy. MCC950 was used to block nod-like receptor protein 3 (NLRP3) inflammasome activity. Echocardiography, immunofluorescence, flow cytometry, and reverse transcription quantitative polymerase chain reaction were used to assess cardiac function, immune cell populations, and inflammatory factor levels. Bulk and single-cell RNA sequencing was used to detect the changes in cardiac transcriptome and immunological network.

RESULTS

NLRP3 inhibition reduced inflammatory response and improved cardiac function. Notably, NLRP3 inhibition also resulted in a pronounced suppression of tumor growth. Single-cell RNA sequencing elucidated that MCC950 treatment reduced the cardiac infiltration of pathogenic macrophages, cytotoxic T cells, activated T cells, and their production of inflammatory cytokines, while enhancing the presence of reparative macrophages and naive T cells. In addition, MCC950 attenuated cardiotoxicity induced by dual programmed cell death protein 1 (PD-1) and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) immunotherapy and promoted tumor regression, and showed efficacy in treating established cardiotoxicity.

CONCLUSIONS

Our findings provide a promising clinical approach for preventing and treating cardiotoxicity induced by ICIs, dissociating the antitumor efficacy of ICI-based therapies from their cardiotoxic side effects.

Immune-checkpoint-inhibitor therapy directed against PD-L1 is tolerated in the heart without manifestation of cardiac inflammation in a preclinical reversible melanoma mouse model

Immune-checkpoint-inhibitors (ICI) target key regulators of the immune system expressed by cancer cells that mask those from recognition by the immune system. They have improved the outcome for patients with various cancer types, such as melanoma. ICI-based therapy is frequently accompanied by immune-related adverse side effects (IRAEs). The reversible melanoma cancer mouse model (B16F10 cells stably expressing a ganciclovir (GCV)-inducible suicide gene in C57BL/6N mice: B16F10-GCV) allows chemotherapy-free tumor elimination in advanced disease stage and demonstrates almost complete recovery of the mouse heart from cancer-induced atrophy, molecular impairment and heart failure. Thus, enabling the study of anti-cancer-therapy effects. Here, we analyzed potential cardiac side effects of antibody-mediated PD-L1 inhibition in the preclinical B16F10-GCV mouse model after tumor elimination and 2 weeks recovery (50 days after tumor inoculation). Anti-PD-L1 treatment was associated with improved survival as compared to isotype control (Ctrl) treated mice. Surviving anti-PD-L1 and Ctrl mice showed similar cardiac function, dimensions and the expression of cardiac stress and hypertrophy markers. Although anti-PD-L1 treatment was associated with increased troponin I type 3 cardiac (TNNI3) blood levels, cardiac mRNA expression of macrophage markers and elevated cardiac levels of secreted inflammatory factors compared to Ctrl treatment, both groups showed a comparable density of inflammatory cells in the heart (using CXCR4-ligand 68Ga-Pentixafor in PET-CT and immunohistochemistry). Thus, anti-PD-L1 therapy improved survival in mice with advanced melanoma cancer with no major cardiac phenotype or inflammation 50 days after tumor inoculation. Without a second hit that triggers the inflammatory response, anti-PD-L1 treatment appears to be safe for the heart in the preclinical melanoma mouse model.

The role of tumor types in immune-related adverse events

Immune checkpoint inhibitors (ICIs) are monoclonal antibodies that block inhibitors of T cell activation and function. With the widespread use of ICIs in cancer therapy, immune-related adverse events (irAEs) have gradually emerged as urgent clinical issues. Tumors not only exhibit high heterogeneity, and their response to ICIs varies, with "hot" tumors showing better anti-tumor effects but also a higher susceptibility to irAEs. The manifestation of irAEs displays a tumor-heterogeneous pattern, correlating with the tumor type in terms of the affected organs, incidence, median onset time, and severity. Understanding the mechanisms underlying the pathogenic patterns of irAEs can provide novel insights into the prevention and management of irAEs, guide the development of biomarkers, and contribute to a deeper understanding of the toxicological characteristics of ICIs. In this review, we explore the impact of tumor type on the therapeutic efficacy of ICIs and further elucidate how these tumor types influence the occurrence of irAEs. Finally, we assess key candidate biomarkers and their relevance to proposed irAE mechanisms. This paper also outlines management strategies for patients with various types of tumors, based on their disease patterns.

Insight of immune checkpoint inhibitor related myocarditis

As the understanding of immune-related mechanisms in the development and progression of cancer advances, immunotherapies, notably Immune Checkpoint Inhibitors (ICIs), have become integral in comprehensive cancer treatment strategies. ICIs reactivate T-cell cytotoxicity against tumors by blocking immune suppressive signals on T cells, such as Programmed Death-1 (PD-1) and Cytotoxic T-lymphocyte Antigen-4 (CTLA-4). Despite their beneficial effects, ICIs are associated with immune-related adverse events (irAEs), manifesting as autoimmune side effects across various organ systems. A particularly alarming irAE is life-threatening myocarditis. This rare but severe side effect of ICIs leads to significant long-term cardiac complications, including arrhythmias and heart failure, and has been observed to have a mortality rate of up to 50% in affected patients. This greatly limits the clinical application of ICI-based immunotherapy. In this review, we provide a comprehensive summary of the current knowledge regarding the diagnosis and management of ICI-related myocarditis. We also discuss the utility of preclinical mouse models in understanding and addressing this critical challenge.

Identification and validation of differentially expressed disulfidptosis-related genes in hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is one of the most common cardiovascular diseases with no effective treatment due to its complex pathogenesis. A novel cell death, disulfidptosis, has been extensively studied in the cancer field but rarely in cardiovascular diseases. This study revealed the potential relationship between disulfidptosis and hypertrophic cardiomyopathy and put forward a predictive model containing disulfidptosis-associated genes (DRGs) of GYS1, MYH10, PDMIL1, SLC3A2, CAPZB, showing excellent performance by SVM machine learning model. The results were further validated by western blot, RNA sequencing and immunohistochemistry in a TAC mice model. In addition, resveratrol was selected as a therapeutic drug targeting core genes using the CTD database. In summary, this study provides new perspectives for exploring disulfidptosis-related biomarkers and potential therapeutic targets for hypertrophic cardiomyopathy.

Immune Checkpoint Inhibitor Myopathy: The Double-Edged Sword of Cancer Immunotherapy

Immune checkpoint inhibitor (ICI) therapy has revolutionized the treatment of several malignancies, with improved survival. These monoclonal antibodies target immune checkpoints, including cytotoxic T-lymphocyte-associated protein 4 (ipilimumab and tremelimumab), programmed death 1 (nivolumab, pembrolizumab, cemiplimab, and dostarlimab), programmed death ligand 1 (atezolizumab, avelumab, and durvalumab), and lymphocyte activation gene 3 (relatlimab), and effectively augment the immune response against tumor cells. Releasing the brakes on the immune system has consequences, however, in the form of immune-related adverse events (irAEs), which may affect any organ. Neurologic irAEs represent 1%-3% of all irAEs, with immune-mediated myopathy (ICI myopathy) being the most common manifestation. Recent large patient series and systematic reviews have established the key features and highlighted new insights into ICI myopathy. ICI myopathy is characterized by an acute or subacute onset of oculobulbar and/or proximal limb weakness, with or without associated respiratory insufficiency and myocarditis. Creatine kinase elevation is common. Oculobulbar presentations with or without respiratory failure may be misattributed to neuromuscular junction disorders, particularly because acetylcholine receptor antibodies are present in up to 40% of patients; however, an electrodiagnostic evidence of a defect of neuromuscular transmission is often absent even in patients with severe weakness, highlighting that the myopathic process is the driving force behind these presentations. Muscle histopathology commonly demonstrates a unique signature of multifocal clusters of necrotic and regenerating fibers, differentiating ICI myopathy from other autoimmune myopathies. Transcriptomic analysis has uncovered distinct subgroups within ICI myopathy, revealing varying degrees of type 1 and type 2 interferon pathway activation alongside notable upregulation of the interleukin (IL)-6 pathway in affected muscle tissue. This discovery presents a promising avenue for intervention through the use of therapies that suppress the interferon pathway and target IL-6 or its receptor. Despite clinical improvements with immunomodulatory therapy, with corticosteroids the mainstay of treatment, mortality remains high, particularly in those with associated myocarditis or respiratory failure requiring intubation, where mortality occurs in up to 50%. ICI withdrawal can lead to cancer progression and death, highlighting a need for improved approaches to ICI rechallenge, performed in limited patients with variable success to date.

Polyfunctional IL-21+ IFNG+ T follicular helper cells contribute to checkpoint inhibitor diabetes mellitus and can be targeted by JAK inhibitor therapy

Immune checkpoint inhibitors (ICI) have revolutionized cancer therapy, but their use is limited by the development of autoimmunity in healthy tissues as a side effect of treatment. Such immune-related adverse events (IrAE) contribute to hospitalizations, cancer treatment interruption and even premature death. ICI-induced autoimmune diabetes mellitus (ICI-T1DM) is a life-threatening IrAE that presents with rapid pancreatic beta-islet cell destruction leading to hyperglycemia and life-long insulin dependence. While prior reports have focused on CD8+ T cells, the role for CD4+ T cells in ICI-T1DM is less understood. Here, we identify expansion CD4+ T follicular helper (Tfh) cells expressing interleukin 21 (IL-21) and interferon gamma (IFNG) as a hallmark of ICI-T1DM. Furthermore, we show that both IL-21 and IFNG are critical cytokines for autoimmune attack in ICI-T1DM. Because IL-21 and IFNG both signal through JAK-STAT pathways, we reasoned that JAK inhibitors (JAKi) may protect against ICI-T1DM. Indeed, JAKi provide robust in vivo protection against ICI-T1DM in a mouse model that is associated with decreased islet-infiltrating Tfh cells. Moreover, JAKi therapy impaired Tfh cell differentiation in patients with ICI-T1DM. These studies highlight CD4+ Tfh cells as underrecognized but critical mediators of ICI-T1DM that may be targeted with JAKi to prevent this grave IrAE.

Immune responses in checkpoint myocarditis across heart, blood and tumour

Immune checkpoint inhibitors are widely used anticancer therapies1 that can cause morbid and potentially fatal immune-related adverse events such as immune-related myocarditis (irMyocarditis)2-5. The pathogenesis of irMyocarditis and its relationship to antitumour immunity remain poorly understood. Here we sought to define immune responses in heart, tumour and blood in patients with irMyocarditis by leveraging single-cell RNA sequencing coupled with T cell receptor (TCR) sequencing, microscopy and proteomics analyses of samples from 28 patients with irMyocarditis and 41 unaffected individuals. Analyses of 84,576 cardiac cells by single-cell RNA sequencing combined with multiplexed microscopy demonstrated increased frequencies and co-localization of cytotoxic T cells, conventional dendritic cells and inflammatory fibroblasts in irMyocarditis heart tissue. Analyses of 366,066 blood cells revealed decreased frequencies of plasmacytoid dendritic cells, conventional dendritic cells and B lineage cells but an increased frequency of other mononuclear phagocytes in irMyocarditis. Fifty-two heart-expanded TCR clones from eight patients did not recognize the putative cardiac autoantigens α-myosin, troponin I or troponin T. Additionally, TCRs enriched in heart tissue were largely nonoverlapping with those enriched in paired tumour tissue. The presence of heart-expanded TCRs in a cycling blood CD8 T cell population was associated with fatal irMyocarditis case status. Collectively, these findings highlight crucial biology driving irMyocarditis and identify putative biomarkers.

Exosomes from human bone marrow MSCs alleviate PD-1/PD-L1 inhibitor-induced myocardial injury in melanoma mice by regulating macrophage polarization and pyroptosis

Myocarditis, which can be triggered by immune checkpoint inhibitor (ICI) treatment, represents a critical and severe adverse effect observed in cancer therapy. Thus, elucidating the underlying mechanism and developing effective strategies to mitigate its harmful impact is of utmost importance. The objective of this study is to investigate the potential role and regulatory mechanism of exosomes derived from human bone marrow mesenchymal stem cells (hBMSC-Exos) in providing protection against myocardial injury induced by ICIs. We observed that the administration of programmed death 1/programmed death-ligand 1 (PD-1/PD-L1) inhibitor BMS-1 in tumor-bearing mice led to evident cardiac dysfunction and myocardial injury, which were closely associated with M1 macrophage polarization and cardiac pyroptosis. Remarkably, these adverse effects were significantly alleviated through tail-vein injection of hBMSC-Exos. Moreover, either BMS-1 or hBMSC-Exos alone demonstrated the ability to reduce tumor size, while the combination of hBMSC-Exos with BMS-1 treatment not only effectively improved the probability of tumor inhibition but also alleviated cardiac anomalies induced by BMS-1.

Management Status of Myocarditis-Related Sudden Cardiac Death

Myocarditis, a life-threatening disease that can result in cardiac arrest and sudden cardiac death, has garnered significant attention in recent years. This review provides a comprehensive overview of the management of myocarditis-related sudden cardiac death, encompassing its pathology, diagnostic methods, therapeutic strategies, preventive measures, prognostic factors, and risk stratification. Additionally, the review highlights current challenges and future directions in this field. The aim is to enhance understanding of myocarditis-related sudden cardiac death and inform clinical practice, ultimately leading to improved patient outcomes.

Modeling immune checkpoint inhibitor associated myocarditis in vitro and its therapeutic implications

Immune checkpoint inhibitor-associated myocarditis is the most lethal side effect of immune checkpoint blockade. Myocarditis leads to persistently increased mortality and lacks effective treatments. The development of patient-relevant disease models may enable disease prediction, increased understanding of disease pathophysiology, and the development of effective treatment strategies. Here, we report a new method to model immune checkpoint inhibitor-associated myocarditis in vitro via a co-culture of activated primary human immune cells, human induced pluripotent stem cell-derived cardiomyocytes, and FDA-approved immune checkpoint inhibitors to recapitulate myocarditis in vitro. Significant cardiomyocyte necrosis, arrhythmia development, and sarcomere destruction occur, replicating clinical findings from myocarditis. This tissue culture myocarditis phenotype may rely on an induced pluripotent stem cell-derived cardiomyocyte antigen-specific CD8+ T cell response. The administration of dexamethasone rescued cardiomyocyte viability, morphology, and electrophysiology and suppressed inflammatory cytokine production. In conclusion, we detail how this platform can effectively model and provide critical information about the morphological and electrophysiological changes induced by immune checkpoint inhibitor-associated myocarditis. We have also validated the ability of this platform to screen potential medications to treat immune checkpoint inhibitor-associated myocarditis. This work establishes a robust, scalable model for identifying new therapies and risk factors, which is valuable in delineating the nature of interactions between the immune system and the heart during myocarditis.

Management of Cancer Therapy-Related Cardiac Dysfunction: A Case-Based Review

With an ever-expanding repertoire of cancer therapies, cardiologists increasingly encounter patients with cancer therapy-related cardiac dysfunction. This can range from asymptomatic mild left ventricular dysfunction to severe symptomatic congestive heart failure. A multidisciplinary approach involving oncologists and cardiologists is needed in the management of these patients. This case-based review provides a practical guide for clinicians regarding the diagnosis and management of cancer therapy-related cardiac dysfunction associated with commonly used cancer treatments: anthracyclines, human epidermal receptor 2-targeted therapies, and immune checkpoint inhibitors.

Immune-Checkpoint Inhibitor-Related Myocarditis: Where We Are and Where We Will Go

Immune checkpoint inhibitors (ICIs) are specific monoclonal antibodies directed against inhibitory targets of the immune system, mainly represented by programmed death-1 (PD1) ligand-1 (PD-L1) and cytotoxic T-lymphocyte antigen-4 (CTLA-4), thus enabling an amplified T-cell-mediated immune response against cancer cells. These drugs have significantly improved prognosis in patients with advanced metastatic cancer (e.g., melanoma, non-small cell lung cancer, renal cell carcinoma). However, uncontrolled activation of anti-tumor T-cells could trigger an excessive immune response, possibly responsible for multi-organ damage, including, among others, lymphocytic myocarditis. The incidence of ICIs-induced myocarditis is underestimated and the patients affected are poorly characterized. The diagnosis and management of this condition are mainly based on expert opinion and case reports. EKG and ultrasound are tests that can help identify patients at risk of myocarditis during treatment by red flags, such as QRS complex enlargement and narrowing of global longitudinal strain (GLS). Therapy of ICI-related myocarditis is based on immunosuppressors, monoclonal antibodies and fusion proteins. A future strategy could involve the use of microRNAs. This review considers the current state of the art of immune-related adverse cardiovascular events, focusing on histological and clinical features, diagnosis and management, including current treatments and future pharmacological targets.

Mechanisms of myocardial toxicity of antitumor drugs and potential therapeutic strategies: A review of the literature

With the successive development of chemotherapy drugs, good results have been achieved in clinical application. However, myocardial toxicity is the biggest challenge. Anthracyclines, immune checkpoint inhibitors, and platinum drugs are widely used. Targeted drug delivery, nanomaterials and dynamic imaging evaluation are all emerging research directions. This article reviews the recent literature on the use of targeted nanodrug delivery and imaging techniques to evaluate the myocardial toxicity of antineoplastic drugs, and discusses the potential mechanisms.

Building an Organ-Wide Macroscopic View of Cancer Hallmarks

Despite an increasingly detailed understanding of cancer hallmarks at molecular or atomic resolution, most studies, however, fall short of investigating the systemic interactions of cancer with the human body. We propose to investigate the hallmarks of cancer from an organ-wide macroscopic view, discuss the challenges in preclinical and clinical research to study the cross-organ regulation of cancer together with potential directions to overcome these challenges, and foresee how this holistic view may be translated into more effective therapies.

Evolving therapeutics and ensuing cardiotoxicities in triple-negative breast cancer

Defined as scarce expression of hormone receptors and human epidermal growth factor receptor 2, triple-negative breast cancer (TNBC) is labeled as the most heterogeneous subtype of breast cancer with poorest prognosis. Despite rapid advancements in precise subtyping and tailored therapeutics, the ensuing cancer therapy-related cardiovascular toxicity (CTR-CVT) could exert detrimental impacts to TNBC survivors. Nowadays, this interdisciplinary issue is incrementally concerned by cardiologists, oncologists and other pertinent experts, propelling cardio-oncology as a booming field focusing on the whole-course management of cancer patients with potential cardiovascular threats. Here in this review, we initially profile the evolving molecular subtyping and therapeutic landscape of TNBC. Further, we introduce various monitoring approaches of CTR-CVT. In the main body, we elaborate on typical cardiotoxicities ensuing anti-TNBC treatments in detail, ranging from chemotherapy (especially anthracyclines), surgery, anesthetics, radiotherapy to immunotherapy, with future perspectives on promising directions in the era of artificial intelligence and traditional Chinese medicine.