In addition, even when an organ is available, transplant rejection presents a continuing problem. Xenograft organs could provide a solution to the shortage of allograft organs. However, hyperacute rejection presents a major problem currently preventing clinical use of xenografts.
Hyperacute rejection is thought to be primarily due to activation of the complement system.
Interaction between platelets and coagulation pathway components has not previously been shown to play a critical role in amplification of the complement activated rejection of xenografts. The present invention also provides methods for screening compounds for their ability to modulate complement activation by inhibiting platelet aggregation and for producing transgenic animals to be used as a source of xenografts. Therefore, compounds which specifically modulate expression of or specifically block the function of these proteins would not affect other integrins or the rest of the complement cascade.