Characterization of the inflammasome IFN-dependent in hiPSC-derived endothelial cells from ICIs-induced myocarditis patients

Abstract

Immune checkpoint inhibitors (ICIs) reactivate T cells to fight tumor cells, unraveling a new approach in cancer treatment. However, cardiovascular complications induced by these ICIs, especially myocarditis, have emerged as particularly dangerous complications with a mortality rate close to 50%. A recent study on cardiac biopsies showed that the IFN-γ pathway and inflammasome regulating proteins was specifically involved in myocarditis induced by ICIs treatment; this mechanism was not found in viral myocarditis and in dilated cardiomyopathies [1] . It is therefore crucial to set up models to study these pathophysiological mechanisms so that the benefit of immunotherapies is not compromised by their adverse cardiac effects. To better understand pathophysiological mechanisms of myocarditis induced by ICIs, we characterized the response to IFN-γ of endothelial cells (hiPSC-EC) generated from cells of patients with and without ICIs-induced myocarditis. We generated human-induced pluripotent stem cell (hiPSC), differentiated in hiPSC-EC, from cells of patients followed in the MediCO Center, Marseille. We considered two groups of patients: with myocarditis (Myoc) and without myocarditis (non-Myoc) following anti-PD-1/anti-CTLA4 immunotherapy. hiPSC-EC were treated with 10 ng/mL of IFN-γ during 48 h. Endothelial cells differentiated from hiPSC clones exhibited the characteristics expected for this cell type in all clones tested, both in the Myoc and non-Myoc patient groups. Stimulation by IFN-γ activated inflammatory intracellular signaling in hiPSC-EC, in particular overexpression of MHC class I and II, and PDL-1. Moreover, changes in the expression of genes of the JAK/STAT pathway and of the inflammasome, particularly the NLRP3 inflammasome, were observed in all groups of tested cells after the IFN-γ stimulation. However, the cells from Myoc patients seemed to be more impaired than those from non-Myoc patients. In particular, hiPSC-EC proliferation was more altered in this group by IFN-γ, and the expression of genes associated with the inflammatory response was strongly increased. Further analyses are in progress to confirm these preliminary data. These preliminary results, obtained in cells reprogrammed from cells of patients with immuno-induced myocarditis, are in agreement with the data published by Finke et al. (2021) in myocardial biopsies, indicating that these hiPSCs are a good model to study the pathophysiological mechanisms associated with the cardiotoxicitiy of anticancer immunotherapy.