PD1 expression inhibits hepoatic inflammation and fibrosis in non-alcoholic steatohepatitis

PD-L1 is a B7-family member that binds to programmed death-1 (PD-1). PD-1 is involved in the negative regulation of immune responses. Recently, we have shown that PD-L1 is expressed on hepatocytes, and that hepatocytes induce apoptosis in T-cells via PD-L1. The aim of this study was to analyzed the expression and function of PD-1 in non-alcoholic steatohepatitis (NASH) in which T-cells play an important pathophysiological role according to most recent studies. Methods and Results: Two different NASH-models were applied to (i) PD-1 deficient (PD1-ko), (ii) PD-1 transgenic (PD1-trg), and (iii) wildtype (wt) contro…