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Lentiviral gene rescue of a Bernard–Soulier mouse model to study platelet glycoprotein Ibβ function
Author(s) -
Strassel C.,
Bull A.,
Moog S.,
Receveur N.,
Mallo L.,
Mangin P.,
Eckly A.,
Freund M.,
DubartKupperschmitt A.,
Gachet C.,
Lanza F.
Publication year - 2016
Publication title -
journal of thrombosis and haemostasis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.947
H-Index - 178
eISSN - 1538-7836
pISSN - 1538-7933
DOI - 10.1111/jth.13355
Subject(s) - platelet , platelet glycoprotein gpib ix complex , von willebrand factor , hemostasis , microbiology and biotechnology , platelet membrane glycoprotein , glycoprotein ib , von willebrand disease , bernard–soulier syndrome , transfection , immunology , chemistry , biology , medicine , cell culture , genetics
Essentials A signaling role of glycoprotein ( GP )Ibβ is postulated but not formally demonstrated in platelets. Lentiviral‐mediated rescue in knock‐out mice can be used to evaluate GPI bβ function in vivo . Transduction of the native subunit corrected the main defects associated with GPI b‐ IX deficiency Deletion of intracellular 159–170 segment increased thrombosis, 150–160 removal increased bleeding.Summary Background The platelet glycoprotein ( GP )Ib‐V‐ IX complex is required for normal hemostasis and megakaryopoiesis. A role in GPI b‐dependent responses has been ascribed to the less well characterized GPI bβ subunit using a specific antibody and GPI b‐ IX transfected cells. Objectives Our aim was to evaluate, in vivo , the role of the GPI bβ in hemostasis and thrombosis. Methods GPI bβ null Sca‐1 + progenitors transduced with viral particles harboring hGPI bβ were transplanted into lethally irradiated GPI bβ −/− recipient mice. Results hGPI bβ transplanted into the bone marrow of GPI bβ null mice rescued GPI b‐ IX expression in 97% of circulating platelets. These platelets efficiently bound von Willebrand factor ( VWF ) and extended filopodia on a VWF matrix, demonstrating the restoration of GPI b‐dependent adhesive and signaling properties. These mice exhibited less severe macrothrombocytopenia and had normal tail bleeding times as compared with GPI bβ null mice. This strategy was employed to manipulate and evaluate the role of the GPI bβ intracellular domain. Removal of the membrane proximal segment (Δ 150–160 ) decreased GPI b‐ IX expression by 43%, confirming its involvement in receptor assembly and biosynthesis, and resulted in increased bleeding times and decreased thrombosis in a mechanical injury model in the aorta. On the other hand, deletion of the C‐flanking 159–170 segment allowed normal GPI b‐ IX expression, VWF ‐dependent responses and bleeding times, but resulted in enhanced arterial thrombosis. Conclusion This pointed to a repressor role of GPI bβ in thrombus formation in vivo that was not predicted in studies of heterologous cells. These results highlight the utility of this lentiviral strategy for the structure‐function evaluation of GPI b‐ IX in platelets.