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WIP regulates signaling via the high affinity receptor for immunoglobulin E in mast cells.

Kettner A, Kumar L, Antón IM, Sasahara Y, de la Fuente M, Pivniouk VI, Falet H, Hartwig JH, Geha RS - J. Exp. Med. (2004)

Bottom Line: Calcium mobilization, phosphorylation of Syk, phospholipase C-g2, and c-Jun NH2-terminal kinase were markedly decreased in WIP-deficient BMMCs.However, the kinetics of actin changes and the cell shape changes that follow FcepsilonRI signaling were altered in WIP-deficient BMMCs.These results suggest that WIP regulates FcepsilonRI-mediated mast cell activation by regulating Syk levels and actin cytoskeleton rearrangement.

View Article: PubMed Central - PubMed

Affiliation: Division of Immunology, Children's Hospital, Harvard Medical School, Boston, MA 02115, USA.

ABSTRACT
Wiskott-Aldrich syndrome protein-interacting protein (WIP) stabilizes actin filaments and is important for immunoreceptor-mediated signal transduction leading to actin cytoskeleton rearrangement in T and B cells. Here we report a role for WIP in signaling pathways downstream of the high affinity receptor for immunoglobulin (Ig)E (FcepsilonRI) in mast cells. WIP-deficient bone marrow-derived mast cells (BMMCs) were impaired in their capacity to degranulate and secrete interleukin 6 after FcepsilonRI ligation. Calcium mobilization, phosphorylation of Syk, phospholipase C-g2, and c-Jun NH2-terminal kinase were markedly decreased in WIP-deficient BMMCs. WIP was found to associate with Syk after FcepsilonRI ligation and to inhibit Syk degradation as evidenced by markedly diminished Syk levels in WIP-deficient BMMCs. WIP-deficient BMMCs exhibited no apparent defect in their subcortical actin network and were normal in their ability to form protrusions when exposed to an IgE-coated surface. However, the kinetics of actin changes and the cell shape changes that follow FcepsilonRI signaling were altered in WIP-deficient BMMCs. These results suggest that WIP regulates FcepsilonRI-mediated mast cell activation by regulating Syk levels and actin cytoskeleton rearrangement.

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Characterization of in vitro–derived WIP−/− BMMCs. (A) IgE receptor expression on BMMCs form WT and WIP−/−. Cells were treated with mouse IgE and then incubated with biotinylated anti-IgE and streptavidin-CyChrome (bold line). Control staining was with biotinylated anti-IgE and streptavidin-CyChrome alone (thin line). (B) WIP protein expression was assessed by immunoblotting after separation of proteins by SDS-PAGE.
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fig1: Characterization of in vitro–derived WIP−/− BMMCs. (A) IgE receptor expression on BMMCs form WT and WIP−/−. Cells were treated with mouse IgE and then incubated with biotinylated anti-IgE and streptavidin-CyChrome (bold line). Control staining was with biotinylated anti-IgE and streptavidin-CyChrome alone (thin line). (B) WIP protein expression was assessed by immunoblotting after separation of proteins by SDS-PAGE.

Mentions: Mouse bone marrow cells cultured in the presence of IL-3 differentiate into mast cells (23). After 4 wk of culture in IL-3–containing WCM, a similar number and percentage of cells (∼90%) from WIP−/− and WT mice differentiated to mast cells as evidenced by their capacity to bind IgE (Fig. 1 A). Furthermore, the same proportion of cells contained metachromatic granules when stained with toluidine blue (not depicted).


WIP regulates signaling via the high affinity receptor for immunoglobulin E in mast cells.

Kettner A, Kumar L, Antón IM, Sasahara Y, de la Fuente M, Pivniouk VI, Falet H, Hartwig JH, Geha RS - J. Exp. Med. (2004)

Characterization of in vitro–derived WIP−/− BMMCs. (A) IgE receptor expression on BMMCs form WT and WIP−/−. Cells were treated with mouse IgE and then incubated with biotinylated anti-IgE and streptavidin-CyChrome (bold line). Control staining was with biotinylated anti-IgE and streptavidin-CyChrome alone (thin line). (B) WIP protein expression was assessed by immunoblotting after separation of proteins by SDS-PAGE.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2211794&req=5

fig1: Characterization of in vitro–derived WIP−/− BMMCs. (A) IgE receptor expression on BMMCs form WT and WIP−/−. Cells were treated with mouse IgE and then incubated with biotinylated anti-IgE and streptavidin-CyChrome (bold line). Control staining was with biotinylated anti-IgE and streptavidin-CyChrome alone (thin line). (B) WIP protein expression was assessed by immunoblotting after separation of proteins by SDS-PAGE.
Mentions: Mouse bone marrow cells cultured in the presence of IL-3 differentiate into mast cells (23). After 4 wk of culture in IL-3–containing WCM, a similar number and percentage of cells (∼90%) from WIP−/− and WT mice differentiated to mast cells as evidenced by their capacity to bind IgE (Fig. 1 A). Furthermore, the same proportion of cells contained metachromatic granules when stained with toluidine blue (not depicted).

Bottom Line: Calcium mobilization, phosphorylation of Syk, phospholipase C-g2, and c-Jun NH2-terminal kinase were markedly decreased in WIP-deficient BMMCs.However, the kinetics of actin changes and the cell shape changes that follow FcepsilonRI signaling were altered in WIP-deficient BMMCs.These results suggest that WIP regulates FcepsilonRI-mediated mast cell activation by regulating Syk levels and actin cytoskeleton rearrangement.

View Article: PubMed Central - PubMed

Affiliation: Division of Immunology, Children's Hospital, Harvard Medical School, Boston, MA 02115, USA.

ABSTRACT
Wiskott-Aldrich syndrome protein-interacting protein (WIP) stabilizes actin filaments and is important for immunoreceptor-mediated signal transduction leading to actin cytoskeleton rearrangement in T and B cells. Here we report a role for WIP in signaling pathways downstream of the high affinity receptor for immunoglobulin (Ig)E (FcepsilonRI) in mast cells. WIP-deficient bone marrow-derived mast cells (BMMCs) were impaired in their capacity to degranulate and secrete interleukin 6 after FcepsilonRI ligation. Calcium mobilization, phosphorylation of Syk, phospholipase C-g2, and c-Jun NH2-terminal kinase were markedly decreased in WIP-deficient BMMCs. WIP was found to associate with Syk after FcepsilonRI ligation and to inhibit Syk degradation as evidenced by markedly diminished Syk levels in WIP-deficient BMMCs. WIP-deficient BMMCs exhibited no apparent defect in their subcortical actin network and were normal in their ability to form protrusions when exposed to an IgE-coated surface. However, the kinetics of actin changes and the cell shape changes that follow FcepsilonRI signaling were altered in WIP-deficient BMMCs. These results suggest that WIP regulates FcepsilonRI-mediated mast cell activation by regulating Syk levels and actin cytoskeleton rearrangement.

Show MeSH
Related in: MedlinePlus