Lookup NU author(s): Dr Jennifer Toomey,
Professor Colin Brooks
Full text for this publication is not currently held within this repository. Alternative links are provided below where available.
Natural killer (NK) cells arise from immature progenitors present in fetal tissues and adult bone marrow, but the factors responsible for driving the proliferation and differentiation of these progenitors are poorly understood. Mouse NK cells had previously been thought not to express interleukin (IL)-2Rα chains, but we show here that immature and mature mouse NK cells express IL-2Rα chain mRNA and that low levels of IL-2Rα chains can be detected on the surface of immature and mature NK cells provided they are cultured in the absence of IL-2. Despite their potential expression of high-affinity IL-2 receptors, immature NK cells only proliferate if IL-2 is present at extremely high concentrations. Surprisingly, IL-15 can also only support the growth of immature NK cells at high, presumably nonphysiological concentrations. Although NK cells express mRNA for the high-affinity IL-15Rα chain, they also express a variety of alternately spliced transcripts whose protein products could potentially disrupt signaling through IL-15 receptors. The requirement for high concentrations of IL-2 and IL-15 suggests that if these cytokines play any role in the proliferative expansion of NK cells in vivo, they act indirectly via other cells or in cooperation with other factors. In support of the latter possibility, we report that the recently described cytokine IL-21 can markedly enhance the proliferation of immature (and mature) NK cells in the presence of doses of IL-2 and IL-15 that by themselves have little growth-promoting activity.
Author(s): Toomey JA, Gays F, Foster D, Brooks CG
Publication type: Article
Publication status: Published
Journal: Journal of Leukocyte Biology
Print publication date: 01/08/2003
Online publication date: 22/05/2003
Acceptance date: 02/04/2003
ISSN (print): 0741-5400
ISSN (electronic): 1938-3673
Publisher: Federation of American Societies for Experimental Biology
PubMed id: 12885940
Altmetrics provided by Altmetric