Inhibitory receptor FcγRIIb mediates the effects of IgG on a phagosome acidification and a sequential dephosphorylation system comprising SHIPs and Inpp4a:

Innate Immunity

TomohiroSegawa¹ 

关键词: Akt;    Fcγ receptor;    phagocytosis;    phosphatase;    phosphoinositide;   

DOI  :  10.1177/1753425917701553

学科分类：生物科学（综合）

来源: Sage Journals

【 摘 要 】

The relative abundance of phosphoinositide (PI) species on the phagosome membrane fluctuates over the course of phagocytosis. PtdIns(3,4,5)P3 and PtdIns(3,4)P2 rapidly increase in the forming of the phagocytic cup, following which they disappear after sealing of the cup. In the present study, we monitored the clearance of these PI species using the enhanced green fluorescent protein-fused pleckstrin homology domain of Akt, a fluorescence probe that binds both PtdIns(3,4,5)P3 and PtdIns(3,4)P2 in Raw 264.7 macrophages. The clearance of PIs was much faster when the phagocytosed particles were coated with IgG. The effect of IgG was not observed in the macrophages deficient in FcγRIIb, an inhibitory IgG receptor. To identify the lipid phosphatases responsible for the FcγRIIb-accelerated PI clearance, we prepared a panel of lipid phosphatase-deficient cells. The lack of a PI 5-phosphatase Src homology 2 domain-containing inositol-5-phosphatase (SHIP)1 or SHIP2 impaired the FcγRIIb-accelerated clearance of PIs....

【 授权许可】

CC BY