Platelet/polymorphonuclear leukocyte interaction: P-selectin triggers protein-tyrosine phosphorylation-dependent CD11b/CD18 adhesion: Role of PSGL-1 as a signaling molecule
Platelet/polymorphonuclear leukocyte interaction: P-selectin triggers protein-tyrosine phosphorylation-dependent CD11b/CD18 adhesion: Role of PSGL-1 as a signaling molecule
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DOI：
10.1182/blood.v93.3.876.403k25_876_885
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发表时间：
1999-02-01
期刊：
影响因子：
20.3
通讯作者：
Cerletti, C
中科院分区：
文献类型：
--
作者：
Evangelista, V;Manarini, S;Cerletti, C
多形核白细胞（PMN）与活化血小板的粘附对于PMN在血管损伤和血栓形成部位的募集是重要的。我们最近发现，在剪切力作用下，混合细胞悬浮液中活化的血小板与中性粒细胞的结合涉及P-选择素和活化的β（2）-整联蛋白CD 11b/CD 18。整合素活化需要对酪氨酸激酶抑制剂敏感的信号传导机制。(1)在这里，我们表明，混合活化，多聚甲醛（PFA）固定的血小板与中性粒细胞在剪切条件下导致快速和完全可逆的酪氨酸磷酸化的一个突出的蛋白质110 kD（P类似于110）。磷酸化是Ca 2+和Mg 2+依赖性的，并且被针对P-选择素或CD 11b/CD 18的抗体阻断，这表明这两种粘附分子需要与它们各自的配体接合以触发类似于110的P的磷酸化。酪氨酸激酶抑制剂对类似于110磷酸化的P的抑制与血小板/PMN聚集的抑制相关。当用P-选择素转染的中国仓鼠卵巢（CHO-P）细胞替代血小板或用P-选择素-IgG融合蛋白刺激PMN时，观察到类似的效果。CHO-P/PMN混合细胞聚集和P-selectin-IgG触发的PMN/PMN聚集以及P类似110磷酸化均被抗P-selectin或CD 18抗体阻断。在每种情况下，PMN粘附对酪氨酸激酶抑制剂genistein敏感。针对P-选择素糖蛋白配体-1（PSGL-1）的抗体PL-1阻断血小板/PMN聚集，表明PSGL-1是本实验系统中P-选择素的主要束缚配体。此外，PSGL-1与非粘附阻断抗体的结合触发了PMN中β（2）-整合素依赖性染料木素敏感性聚集以及酪氨酸磷酸化。这项研究表明，P-选择素与PSGL-1的结合触发了酪氨酸激酶依赖的机制，导致PMN中的CD 11b/CD 18活化。与邻近细胞上的配体接合的Pn-整联蛋白的可用性对于类似于110的P的酪氨酸磷酸化是必需的。(C)1999年，美国血液学会。
Polymorphonuclear leukocyte (PMN) adhesion to activated platelets is important for the recruitment of PMN at sites of vascular damage and thrombus formation. We have recently shown that binding of activated platelets to PMN in mixed cell suspensions under shear involves P-selectin and the activated beta(2)-integrin CD11b/CD18. Integrin activation required signaling mechanisms that were sensitive to tyrosine kinase inhibitors.(1) Here we show that mixing activated, paraformaldehyde (PFA)-fixed platelets with PMNs under shear conditions leads to rapid and fully reversible tyrosine phosphorylation of a prominent protein of 110 kD (P similar to 110). Phosphorylation was both Ca2+ and Mg2+ dependent and was blocked by antibodies against P-selectin or CD11b/CD18, suggesting that both adhesion molecules need to engage with their respective ligands to trigger phosphorylation of P similar to 110. The inhibition of P similar to 110 phosphorylation by tyrosine kinase inhibitors correlates with the inhibition of platelet/PMN aggregation. Similar effects were observed when platelets were substituted by P-selectin-transfected Chinese hamster ovary (CHO-P) cells or when PMN were stimulated with P-selectin-IgG fusion protein. CHO-P/PMN mixed-cell aggregation and P-selectin-IgG-triggered PMN/PMN aggregation as well as P similar to 110 phosphorylation were all blocked by antibodies against P-selectin or CD18. In each case PMN adhesion was sensitive to the tyrosine kinase inhibitor genistein, The antibody PL-1 against P-selectin glycoprotein ligand-1 (PSGL-1) blocked platelet/PMN aggregation, indicating that PSGL-1 was the major tethering ligand for P-selectin in this experimental system. Moreover, engagement of PSGL-1 with a nonadhesion blocking antibody triggered beta(2)-integrin-dependent genistein-sensitive aggregation as well as tyrosine phosphorylation in PMN. This study shows that binding of P-selectin to PSGL-1 triggers tyrosine kinase-dependent mechanisms that lead to CD11b/CD18 activation in PMN. The availability of the Pn-integrin to engage with its ligands on the neighboring cells is necessary for the tyrosine phosphorylation of P similar to 110. (C) 1999 by The American Society of Hematology.