IL-2-activated murine newborn liver NK cells enhance engraftment of hematopoietic stem cells in MHC-mismatched recipients.
To explore the modulatory effects of IL-2-activated NK cells on hematopoietic stem cell (HSC) engraftment further, we used fresh newborn liver cells (NLC) and IL-2-activated newborn liver cells (ANLC) as combined sources, respectively, of transplanted HSC and IL-2-activated NK cells free of contaminating CD3+ T cells. As previously found with adult IL-2-activated spleen cells, NLC cultured with IL-2 for 7 days exhibited lymphokine-activated killer (LAK) activity, veto activity, and natural suppressor activity, and enhanced both short-term and long-term stem cell engraftment by intact co-injected syngeneic and allogeneic NLC in totally MHC-mismatched lethally irradiated recipients. However, unlike adult IL-2-stimulated adult spleen cells, IL-2-activated NLC lacked CD3+ T cells and failed to induce lethal GVHD. FACS analysis and cell sorting experiments showed that the cells in ANLC which enhanced short-term HSC engraftment belonged to the relatively immature CD3-NK1.1-2B4+ NK cell subset. By contrast, cells belonging to the more mature CD3-NK1.1+2B4+ NK cell subset showed no HSC-enhancing effects. Identification and isolation in humans of similar NK cell enhancers of HSC could lead to a new approach to improving stem cell engraftment in MHC-mismatched recipients without increasing the risk of GVHD.
Hirayama
M
M
Department of Pediatrics, Wayne State University School of Medicine, Detroit, MI, USA.
Genyea
C
C
Brownell
A
A
Kaplan
J
J
D000818:Animals; D000831:Animals, Newborn; D018380:Hematopoietic Stem Cell Transplantation; D006650:Histocompatibility Testing; D007376:Interleukin-2 / Q000494:pharmacology*; D007694:Killer Cells, Natural / Q000276:immunology*; D008099:Liver / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D014184:Transplantation, Homologous
D007376:Interleukin-2