Fast clearance of platelets in a commonly used mouse model for GPIbα is impeded by an anti-GPIbβ antibody derivative.
Fast clearance of platelets in a commonly used mouse model for GPIbα is impeded by an anti-GPIbβ antibody derivative.
复制标题
DOI：
10.1111/jth.15702
复制
发表时间：
2022-06
期刊：
影响因子：
--
通讯作者：
中科院分区：
文献类型：
--
作者：
糖蛋白(GP)Ibα在调节血小板清除中起重要作用。最近，我们在GPIBα中发现了机械感受域，并有证据表明，GPIBα机械感受域的展开会导致其中的触发序列暴露，随后的GPIB-IX信号会加速血小板的清除。在一个常用的转基因小鼠模型IL4R-IbαTg中，触发序列是结构性暴露的，存在结构性GPIB-IX介导的细胞信号。它们的血小板清除速度也明显快于野生型小鼠。此前，一种抗GPIBβ抗体RAM.1被开发出来。RAM1抑制依赖于GPIBα的血小板信号和激活。此外，RAM.1还抑制抗GPIBα抗体介导的丝状足的形成。目的：研究RAM.1是否能改善触发序列暴露所介导的血小板清除。共聚焦显微镜(奥林巴斯FV1000)测量自发性丝状足底。用流式细胞仪检测其他血小板信号转导事件。用Alexa 488标记的抗鼠Gpix抗体追踪内源性血小板寿命。稳定表达IL4R-Ib嵌合α蛋白复合体的中国仓鼠卵巢细胞在IL4R-IbαTg小鼠体内也表现出丝状伪足，这种丝状伪足可被RAM1处理取消。此外，输注不含Fc部分的重组RAM1衍生物可显著延长IL4R-IbαTG血小板的内源性寿命。这些结果提供了支持触发序列暴露与加速的血小板清除有关的关键证据，并表明RAM1衍生物可能被开发用于治疗GPIB-IX介导的血小板减少症。
Glycoprotein (GP)Ibα plays a critical role in regulating platelet clearance. Recently, we identified the mechanosensory domain (MSD) in GPIbα and reported evidence to suggest that unfolding of the GPIbα MSD induces exposure of the Trigger sequence therein and subsequent GPIb-IX signaling that accelerates platelet clearance. In a commonly used transgenic mouse model, IL4R-IbαTg, where the Trigger sequence is constitutively exposed, constitutive GPIb-IX-mediated cellular signals are present. Clearance of their platelets is also significantly faster than that of wild-type mice. Previously, an anti-GPIbβ antibody RAM.1 was developed. RAM.1 inhibits GPIbα-dependent platelet signaling and activation. Further, RAM.1 also inhibits anti-GPIbα antibody-mediated filopodia formation. To investigate whether RAM.1 can ameliorate trigger sequence exposure-mediated platelet clearance. Spontaneous filopodia were measured by confocal microscopy (Olympus FV1000). Other platelet signaling events were measured by flow cytometry. Endogenous platelet life span was tracked by Alexa 488 labeled anti-mouse GPIX antibody. Transfected Chinese hamster ovary cells stably expressing the same chimeric IL4R-Ibα protein complex as in IL4R-IbαTg mice also constitutively exhibit filopodia, and that such filopodia could be abolished by treatment of RAM.1. Further, transfusion of a recombinant RAM.1 derivative that is devoid of its Fc portion significantly extends the endogenous life span of IL4R-IbαTg platelets. These results provide the key evidence supporting the causative link of Trigger sequence exposure to accelerated platelet clearance, and suggest that a RAM.1 derivative may be therapeutically developed to treat GPIb-IX-mediated thrombocytopenia.
登录
查看更多内容
DOI：
10.1111/jth.12144
发表时间：
2013-04
期刊：
Journal of thrombosis and haemostasis : JTH
影响因子：
--
作者：
Li R;Emsley J
通讯作者：
Emsley J
影响因子：
3.3
作者：
Joglekar MV;Ware J;Xu J;Fitzgerald ME;Gartner TK
通讯作者：
Gartner TK
影响因子：
16.6
作者：
Duetting, Sebastian;Gaits-Iacovoni, Frederique;Nieswandt, Bernhard
通讯作者：
Nieswandt, Bernhard
影响因子：
10.4
作者：
Getz, T. M.;Piatt, R.;Bergmeier, W.
通讯作者：
Bergmeier, W.
影响因子：
20.3
作者：
Canault, Matthias;Duerschmied, Daniel;Wagner, Denisa D.
通讯作者：
Wagner, Denisa D.