Single-cell Atlas of intrahepatic T cells reveals a population of liver-resident naive-like CD4+ T cells expanded in primary sclerosing cholangitis

The composition of intrahepatic immune cells in primary sclerosing cholangitis (PSC) and their contribution to disease pathogenesis is widely unknown. We here generated a single-cell atlas of intrahepatic T cells in PSC, a type of immune cells that has previously been involved in the pathogenesis of PSC. This atlas provides a valuable data source to the field. Using that atlas, we identified a population of liver-resident naive-like CD4+ T cells which are expanded in livers of patients with PSC compared to healthy and other liver diseases. Trajectory inference suggest that these cells have a propensity to acquire TH17-associated effector functions. Using blood-derived cells naive CD4+ T cells we experimentally prove this propensity. Since TH17-polarized cells are considered to contribute to the development of PSC, our findings point towards a so far underestimated role of naive T cells in PSC.