Non-alcoholic steatohepatitis (NASH) involves steatosis combined with inflammation, which can progress into fibrosis and cirrhosis. Exploring the molecular mechanisms of NASH is highly dependent on the availability of animal models. Currently, the most commonly used animal models for NASH imitate particularly late stages of human disease. Thus, there is a need for an animal model that can be used for investigating the factors that potentiate the inflammatory response within NASH. We have previously shown that 7-day high-fat-high-cholesterol (HFC) feeding induces steatosis and inflammation in both APOE2ki and Ldlr−/− mice. However, it is not known whether the early inflammatory response observed in these mice will sustain over time and lead to liver damage. We hypothesized that the inflammatory response in both models is sufficient to induce liver damage over time. APOE2ki and Ldlr−/− mice were fed a chow or HFC diet for 3 months. C57Bl6/J mice were used as control. Surprisingly, hepatic inflammation was abolished in APOE2ki mice, while it was sustained in Ldlr−/− mice. In addition, increased apoptosis and hepatic fibrosis was only demonstrated in Ldlr−/− mice. Finally, bone-marrow-derived-macrophages of Ldlr−/− mice showed an increased inflammatory response after oxidized LDL (oxLDL) loading compared to APOE2ki mice. Ldlr−/− mice, but not APOE2ki mice, developed sustained hepatic inflammation and liver damage upon long term HFC feeding due to increased sensitivity for oxLDL uptake. Therefore, the Ldlr−/− mice are a promising physiological model particularly vulnerable for investigating the onset of hepatic inflammation in non-alcoholic steatohepatitis.
Immune-checkpoint inhibitors (ICIs) activate the immune system to assault cancer cells in a manner that is not antigen specific. We hypothesized that tolerance may also be broken to autoantigens, resulting in autoantibody formation, which could be associated with immune-related adverse events (irAEs) and antitumor efficacy. Twenty-three common clinical autoantibodies in pre- and posttreatment sera from 133 ipilimumab-treated melanoma patients were determined, and their development linked to the occurrence of irAEs, best overall response, and survival. Autoantibodies developed in 19.2% (19/99) of patients who were autoantibody-negative pretreatment. A nonsignificant association was observed between development of any autoantibodies and any irAEs [OR, 2.92; 95% confidence interval (CI) 0.85–10.01]. Patients with antithyroid antibodies after ipilimumab had significantly more thyroid dysfunction under subsequent anti–PD-1 therapy: 7/11 (54.6%) patients with antithyroid antibodies after ipilimumab developed thyroid dysfunction under anti–PD1 versus 7/49 (14.3%) patients without antibodies (OR, 9.96; 95% CI, 1.94–51.1). Patients who developed autoantibodies showed a trend for better survival (HR for all-cause death: 0.66; 95% CI, 0.34–1.26) and therapy response (OR, 2.64; 95% CI, 0.85–8.16). We conclude that autoantibodies develop under ipilimumab treatment and could be a potential marker of ICI toxicity and efficacy.