title: NK cells can generate from precursors in the adult human liver.
abstract: Hepatic NK cells constitute ≈ 40% of hepatic lymphocytes and are phenotypically and functionally distinct from blood NK cells. Whether hepatic NK cells derive from precursors in the BM or develop locally from hepatic progenitors is still unknown. Here, we identify all five known sequential stages of NK-cell development in the adult human liver and demonstrate that CD34(+) hepatic progenitors can generate functional NK cells. While early NK-cell precursors (NKPs) were similar in liver and blood, hepatic stage 3 NKPs displayed immunophenotypical differences, suggesting the onset of a liver-specific NK-cell development. Hepatic stage 3 NKPs were RORC(neg) and did not produce IL-17 or IL-22, excluding them from the lymphoid tissue-inducer (LTi) subset. In vitro culture of hepatic NKPs gave rise to functional NK cells exhibiting strong cytotoxicity against K562 targets. To determine whether hepatic NKPs are stably residing in the liver, we analyzed donor and recipient-derived cells in transplanted livers. Shortly after liver transplantation all donor NKPs in liver grafts were replaced by recipient-derived ones, indicating that hepatic NKPs are recruited from the bloodstream. Together, our results show that NKPs are continuously recruited from peripheral blood into the liver and can potentially differentiate into liver-specific NK cells.
authors.affiliation: Department of Gastroenterology and Hepatology, Erasmus MC, Rotterdam, The Netherlands.
authors.forename: Viviana
authors.initials: V
authors.lastname: Moroso
authors.forename: Farbod
authors.initials: F
authors.lastname: Famili
authors.forename: Natalie
authors.initials: N
authors.lastname: Papazian
authors.forename: Tom
authors.initials: T
authors.lastname: Cupedo
authors.forename: Luc J W
authors.initials: LJ
authors.lastname: van der Laan
authors.forename: Geert
authors.initials: G
authors.lastname: Kazemier
authors.forename: Herold J
authors.initials: HJ
authors.lastname: Metselaar
authors.forename: Jaap
authors.initials: J
authors.lastname: Kwekkeboom
mesh_terms: D000328:Adult; D002454:Cell Differentiation / Q000276:immunology*; D002469:Cell Separation; D005434:Flow Cytometry; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000276:immunology; D006801:Humans; D007694:Killer Cells, Natural / Q000166:cytology* / Q000276:immunology; D008099:Liver / Q000166:cytology* / Q000276:immunology*; D016133:Polymerase Chain Reaction