Liver type 1 innate lymphoid cells develop locally via an interferon-γ-dependent loop

The pathways that lead to the development of tissue-resident lymphocytes, including liver type 1 innate lymphoid cells (ILC1s), remain unclear. We show here that the adult mouse liver contains Lin(-)Sca-1(+)Mac-1(+) hematopoietic stem cells derived from the fetal liver. This population includes Lin-CD122(+)CD49a(+) progenitors that can generate liver ILC1s but not conventional natural killer cells. Interferon-gamma (IFN-gamma) production by the liver ILC1s themselves promotes the development of these cells in situ, through effects on their IFN-gamma R+ liver progenitors. Thus, an IFN-gamma-dependent loop drives liver ILC1 development in situ, highlighting the contribution of extramedullary hematopoiesis to regional immune composition within the liver.

Automated summary

Research indicates that the adult mouse liver contains lineage-CD122(+)CD49a(+) progenitor cells for liver ILC1s derived from fetal liver. The production of IFN-gamma by liver ILC1s themselves promotes their development in situ, emphasizing the role of extramedullary hematopoiesis in liver immune composition.