Human immune response to porcine xenoantigen

The human immune response to porcine xenoantigens is the primary barrier to xenotransplantation, involving the rapid recognition and destruction of transplanted pig tissues by pre-existing human antibodies and innate immune mechanisms. The most important xenoantigens are glycan structures (e.g., α1,3Gal) expressed on pig cells, which are recognized by natural human antibodies, triggering classical complement activation, endothelial injury, and hyperacute rejection[4][5]. Innate immune cells, particularly NK cells and macrophages, participate in both antibody-dependent and direct cellular cytotoxicity. NK cell activation is driven by the failure of porcine MHC (SLA) molecules to engage inhibitory receptors on human NK cells, while also involving activating receptor-ligand pairs (e.g., CD2-CD58, NKG2D-pULBP1)[1][2][3][6]. Complement activation, cytokine release, and further adaptive immune cell recruitment amplify the rejection process. Current strategies to overcome these barriers include genetically modifying pigs to remove major xenoantigens and/or express human complement regulatory proteins, as well as using immunosuppressive drugs and immune-targeting biologics[5][6].

Other names

Human anti-pig xenoimmunityHuman xenoreactive response to porcine antigensHuman xenotransplant rejection response

Suppression of T cell and B cell activation (immunosuppression) - Inhibition of complement cascade - Blockade of Fc receptor-mediated ADCC - Blockade of adhesion molecule interactions - Depletion of antibodies