Negative regulation of FcεRI signaling by FcγRII costimulation in human blood basophils
Negative regulation of FcεRI signaling by FcγRII costimulation in human blood basophils
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DOI：
10.1067/mai.2000.107931
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发表时间：
2000-08-01
影响因子：
14.2
通讯作者：
Oliver, JM
中科院分区：
文献类型：
--
作者：
Kepley, CL;Cambier, JC;Oliver, JM
背景资料：通过人B和T细胞的抗原受体和啮齿动物肥大细胞的高亲和力IgE受体Fc γ RII的信号传导通过将这些受体与低亲和力IgE受体Fc γ RII交联而降低。认为该抑制涉及Fc γ RIIB胞质尾中基于免疫受体酪氨酸的抑制基序（ITIM）的酪氨酸磷酸化，为含SH 2的蛋白质创造结合位点（含有Src同源结构域的蛋白酪氨酸磷酸酶1和2 [SHP-1，SHP-2]）和/或脂质（含SH 2结构域的聚磷脂酰肌醇5-磷酸酶）磷酸酶对抗来自共刺激抗原受体的激活信号，目的：在人类嗜碱性粒细胞和肥大细胞中，Fc β RI信号传导产生负责过敏性炎症的介质和细胞因子。我们建议，以确定是否Fc γ RII共刺激在人类嗜碱性粒细胞的Fc γ RI信号被抑制，并探讨潜在的机制，作为一种方法，以提高治疗过敏性inflammation.Methods：Fc γ R的表达人类嗜碱性粒细胞，采用流式细胞术和RT-PCR分析。Fc γ RII/Fc γ RI共刺激通常通过用抗二硝基酚（DNP）IgE和抗DNP Ige引发细胞并用DNP-BSA刺激来实现。通过蛋白质印迹鉴定磷酸酶，并通过细胞分级分离确定它们在膜和胞质溶胶之间的分配。将生物素化的合成肽和对应于Fc γ RIIB ITIM序列的磷酸肽用于吸附测定。我们报告外周血嗜碱性粒细胞表达Fc γ RII，（在含有ITIM的Fc γ RIIB和含有免疫受体酪氨酸基序的活化基序的Fc γ RIIA形式中）并且共刺激Fc γ RII和Fc γ RI抑制嗜碱性粒细胞Fc γ RI介导的组胺释放、IL-4产生和Ca 2+动员。Fc γ RII/Fc γ RI共刺激对嗜碱性粒细胞Fc γ RI信号传导的抑制与Syk酪氨酸磷酸化的显著降低有关，人嗜碱性粒细胞表达所有3种含SH 2的磷酸酶。Fc γ RII/Fc γ RIIB共刺激诱导SHP-1从嗜碱性粒细胞的胞质部分易位至膜部分以及对应于磷酸化Fc γ RIIB ITIM序列的生物素化合成肽特异性募集SHP-1的证据1的蛋白磷酸酶特别暗示了这种蛋白磷酸酶参与了共刺激的Fc γ RII对Fc γ RI信号传导的负调节。
Background: Signaling through the antigen receptors of human B and T cells and the high-affinity IgE receptor Fc epsilon RI of rodent mast cells is decreased by cross-linking these receptors to the low-affinity Ige receptor Fc gamma RII, The inhibition is thought to involve the tyrosine phosphorylation of immunoreceptor tyrosine-based inhibitory motifs (ITIMs) in the Fc gamma RIIB cytoplasmic tail, creating binding sites For SH2-containing protein (Src homology domain containing protein tyrosine phosphatase 1 and 2 [SHP-1, SHP-2]) and/or lipid (SH2 domain-containing polyphosphatidylinositol 5-phosphatase) phosphatases that oppose activating signals from the costimulated antigen receptors,Objective: In human basophils and mast cells Fc epsilon RI signaling generates mediators and cytokines responsible for allergic inflammation. We proposed to determine whether Fc epsilon RI signaling is inhibited by Fc gamma RII costimulation in human basophils and to explore the underlying mechanism as an approach to improving the treatment of allergic inflammation.Methods: Fc gamma R expression on human basophils was examined using flow cytometry and RT-PCR analysis. Fc gamma RII/Fc epsilon RI costimulation was typically accomplished by priming cells with anti-dinitrophenol (DNP) IgE and anti-DNP Ige and stimulating with DNP-BSA. Phosphatases were identified by Western blotting, and their partitioning between membrane and cytosol was determined by cell fractionation, Biotinylated synthetic peptides and phosphopeptides corresponding to the Fc gamma RIIB ITIM sequence were used for adsorption assays.Results: We report that peripheral blood basophils express Fc gamma RII (in both the ITIM-containing Fc gamma RIIB and the immunoreceptor tyrosine-based activation motif-containing Fc gamma RIIA forms) and that costimulating Fc gamma RII and Fc epsilon RI inhibits basophil Fc epsilon RI-mediated histamine release, IL-4 production, and Ca2+ mobilization, The inhibition of basophil Fc epsilon RI signaling by Fc gamma RII/Fc epsilon RI costimulation is linked to a significant decrease in Syk tyrosine phosphorylation, Human basophils express all 3 SH2-containing phosphatases.Conclusions: Evidence that Fc gamma RII/Fc epsilon RI costimulation induces SHP-1 translocation from the cytosolic to membrane fractions of basophils and that biotinylated synthetic peptides corresponding to the phosphorylated Fc gamma RIIB ITIM sequence specifically recruit SHP-1 from basophil Lysates particularly implicates this protein phosphatase in the negative regulation of Fc epsilon RI signaling by costimulated Fc gamma RII.