Humanized GPIbα-von Willebrand factor interaction in the mouse

Area of Science:

• Hematology
• Vascular Biology
• Translational Medicine

Background:

• Platelet glycoprotein Ibα (GPIbα) interaction with von Willebrand factor (VWF) is key in hemostasis and thrombosis.
• Species-specific binding has limited antithrombotic drug development due to a lack of suitable animal models.

Purpose of the Study:

• To create a mouse model with humanized GPIbα-VWF binding for studying hemostasis and thrombosis.
• To validate this model for preclinical antithrombotic drug screening.

Main Methods:

• Generated a knockin mouse strain with human VWF exon 28 (VWF^h28).
• Crossbred VWF^h28 mice with human GPIbα transgenic mice to create H1HA mice with humanized binding.
• Assessed hemostasis and thrombosis using tail bleeding times and carotid artery injury models.
• Measured GPIbα-VWFA1 binding affinity using surface plasmon resonance.

Main Results:

• The H1HA mouse strain exhibited humanized GPIbα-VWF binding.
• Bleeding times were prolonged and thrombogenesis attenuated in H1HA mice compared to controls.
• Monoclonal antibody NMC-4 inhibited platelet aggregation and thrombosis in the humanized model, mirroring human responses.

Conclusions:

• The H1HA mouse is a fully humanized model for studying GPIbα-VWF interactions.
• This model offers valuable insights into human hemostatic and thrombotic disorders.
• It serves as a platform for evaluating antithrombotic therapies targeting GPIbα-VWF binding.