Immune checkpoint inhibitor therapy increases systemic SDF-1, cardiac DAMPs Fibronectin-EDA, S100/Calgranulin, Galectine-3 and NLRP3-MyD88-chemokine pathways.

Abstract

e14516 Background: Several strategies based on immune checkpoint inhibitors (ICIs) have been developed or are under investigation for cancer therapy for improving cancer therapy outcomes. However, several ICIs-induced side effects emerged in a fraction of these patients, especially a rare but clinically significant cardiotoxicity with high rate of mortality. We studied the pro-inflammatory and pro-fibrotic effects of short-term ICIs therapy in preclinical models. Methods: C57/Bl6 mice were treated with Ipilimumab, Pembrolizumab or Nivolumab (15 mg/kg) through intraperitoneal injections for 10 days. Before (T0) and after treatments (T10), analysis of fractional shortening, ejection fraction, radial and longitudinal strain were performed through 2D-echocardiography (Vevo 2100, Visual Sonics Fujfilm). Fibrosis, necrosis, hypertrophy and vascular/myocardial NF-kB expression were analyzed through Immunohistochemistry (IHC) of treated cardiac tissues. Systemic levels of SDF-1, myocardial expression of DAMPs (Fibronectin-EDA, S100/Calgranulin, Galectine-3), NLRP3, MyD88 and twelve cytokines/growth factors have been analyzed. In parallel, in a human in vitro model, human cardiomyocytes co-cultured with hPBMC were exposed to ICIs (200 nM) for 72h. After treatment, production of DAMPs and 12 cytokines/growth factors were analyzed in the supernatant through colorimetric and enzymatic assays. Results: Radial and longitudinal strain were decreased after 10 days of ICIs therapy. Histological analysis of NF-kB expression shows that short-term anti-CTLA-4 or anti-PD-1 treatment increased vascular and myocardial inflammation. No myocardial hypertrophy was seen with the exception of the pembrolizumab group. Systemic SDF-1 was drastically increased after treatment with ICIs. Myocardial fibrosis and expression of galectin-3, pro-collagen 1-α and MMP-9 were increased after treatment with all ICIs. Both anti-CTLA-4 or anti-PD-1 treatments increased the expression of DAMPs, NLRP3 inflammasome and MyD88. Conclusions: This study demonstrates that therapy with anti-CTLA-4 and anti-PD-1 antibodies increases systemic SDF-1 and myocardial NLRP3, MyD88 and DAMPs expression in preclinical models. A significant secretion of pro-inflammatory cytokines in myocardial tissue was also induced after ICIs therapy. Significant histological changes were seen and strong vascular NF-kB expression was observed in all groups.