TY - JOUR
T1 - Differential expression of SHIP1 in CD56bright and CD56 dim NK cells provides a molecular basis for distinct functional responses to monokine costimulation
AU - Trotta, Rossana
AU - Parihar, Robin
AU - Yu, Jianhua
AU - Becknell, Brian
AU - Allard, Jeffrey
AU - Wen, Jing
AU - Ding, Wei
AU - Mao, Hsiaoyin
AU - Tridandapani, Susheela
AU - Carson, William E.
AU - Caligiuri, Michael A.
PY - 2005/4/15
Y1 - 2005/4/15
N2 - Monocyte cytokines (ie, monokines) induce natural killer (NK) cells to produce interferon-γ (IFN-γ), which is critical for monocyte clearance of infectious pathogens and tumor surveillance. Human CD56 bright NK cells produce far more IFN-γ in response to monokines than do CD56dim NK cells. The kinases and phosphatases involved in regulating IFN-γ production by monokine-activated NK cells are not clearly identified. SHIP1 is a 5′ inositol phosphatase that dephosphorylates the phosphatidylinositol-3 kinase (PI-3K) product PI3,4,5P3. Here, we show that constitutive expression of SHIP1 is distinctly lower in CD56 bright NK cells compared with CD56dim NK cells, suggesting it could be an important negative regulator of IFN-γ production in monokine-activated NK cells. Indeed, overexpression of SHIP1 in CD56 bright NK cells followed by monokine activation substantially lowered IFN-γ production. This effect was not seen when NK cells were infected with a SHIP1 mutant containing an inactive catalytic domain. Finally, NK cells in SHIP1-/- mice produced more IFN-γ in response to monokines in vivo than did NK cells from wild-type mice. Collectively, these results demonstrate that SHIP1 negatively regulates monokine-induced NK cell IFN-γ production in vitro and in vivo and provide the first molecular explanation for an important functional distinction observed between CD56bright and CD56dim human NK subsets.
AB - Monocyte cytokines (ie, monokines) induce natural killer (NK) cells to produce interferon-γ (IFN-γ), which is critical for monocyte clearance of infectious pathogens and tumor surveillance. Human CD56 bright NK cells produce far more IFN-γ in response to monokines than do CD56dim NK cells. The kinases and phosphatases involved in regulating IFN-γ production by monokine-activated NK cells are not clearly identified. SHIP1 is a 5′ inositol phosphatase that dephosphorylates the phosphatidylinositol-3 kinase (PI-3K) product PI3,4,5P3. Here, we show that constitutive expression of SHIP1 is distinctly lower in CD56 bright NK cells compared with CD56dim NK cells, suggesting it could be an important negative regulator of IFN-γ production in monokine-activated NK cells. Indeed, overexpression of SHIP1 in CD56 bright NK cells followed by monokine activation substantially lowered IFN-γ production. This effect was not seen when NK cells were infected with a SHIP1 mutant containing an inactive catalytic domain. Finally, NK cells in SHIP1-/- mice produced more IFN-γ in response to monokines in vivo than did NK cells from wild-type mice. Collectively, these results demonstrate that SHIP1 negatively regulates monokine-induced NK cell IFN-γ production in vitro and in vivo and provide the first molecular explanation for an important functional distinction observed between CD56bright and CD56dim human NK subsets.
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U2 - 10.1182/blood-2004-10-4072
DO - 10.1182/blood-2004-10-4072
M3 - Article
C2 - 15604218
AN - SCOPUS:20144389496
SN - 0006-4971
VL - 105
SP - 3011
EP - 3018
JO - Blood
JF - Blood
IS - 8
ER -