Cell surface PD-L1 expression of activated intrahepatic MPs decreased by ex vivo TAF treatment
We established an animal TAA-induced liver injury model to identify theex vivo TAF effects on inflamed intrahepatic MPs. TAA was injected intraperitoneally for 8 weeks (Fig 4A). H&E staining of paraffin-embedded liver sections showed that hepatocyte necrosis and sinusoidal congestion were significantly higher in the TAA-treated group’s livers than in those of the no TAA-treated ones. Sirius red staining showed that the collagen deposition area was increased in the TAA-treated group’s livers compared to that in the no TAA-treated group (Fig 4B). The TAA-treated injured livers were perfused with collagenase, and MPs were isolated using gradient centrifugation. The isolated MPs were treated with different TAF concentrations (Fig 4C). TAF- or mock-treated MPs were analysed using flow cytometry. The number of PD-L1+ cells among the total analysed MPs was decreased by TAF in a concentration-dependent manner (Fig 4D). TAF treatment decreased the MFI of PD-L1 in CD11b+F4/80+ intrahepatic MPs (Fig 4E).