ANTI-HUMAN PLATELET TETRASPANIN (CD9) MONOCLONAL ANTIBODIES INDUCE PLATELET INTEGRIN αlbβ3 ACTIVATION IN AFc RECEPTOR-INDEPENDENT FASHION
- Author:
Huaizhu WU
1
;
Jiazeng LI
;
Lin PENG
;
Hanzhi LIU
;
Wenjie WU
;
Yuling ZHOU
;
Qingming HOU
;
Dehong KONG
Author Information
1. Institute of Hematology, CAMS & PUMC
- Keywords:
platelets;
integrin αⅡbβ3;
tetraspanin
- From:
Chinese Medical Sciences Journal
2000;15(3):145-149
- CountryChina
- Language:Chinese
-
Abstract:
Objective. This study characterized the activation of platelet integrin aⅡbβ3 induced by two anti-human platelet te-traspanin monoclonal antibodies(mAbs),HI117 and SJ9A4. Methods. Using 125I-labeled human fibdnogen(Fg), specific Fg binding to human platelets induced by HI117 and SJ9A4 was measured as indication of activation of platelet integrin αⅡbβ3 by the two mAbs. Results. H1117 and SJ9A4( 10μg/ml and 20μg/ml) induced evident specific Fg binding to human platelets, sug-gesting that the two mAbs evoked activation of platelet integrin αⅡbβ3. Further study indicated that HI117 and SJ9A4 induced integrin t Ⅱ 1β3 activation independent of platelet Fc-receptors, and that HI117 and SJ9A4-induced integrin αⅡbβ3 activation was inhibited by sphingosing, aspirin, apyrase, and/or PGI2. Conclusion. The anti-platelet tetraspanin(CD9)mAbe,HI117 and SJ9A4, can induce platelet integrin αⅡbβ3 act-vation independent of Fc-receptors. Three signaling pathways,i.e.thromboxane,secreted ADP, and cAMP pathways may be involved in the process, with protein kimse C activation presumably being the comtmon step of the three pathways.
