Fig. 8

a IFN- γ-activation increases the proliferative response of human peripheral blood mononuclear cells (PBMCs) to wild-type (WT) and GTKO pig aortic endothelial cells (pAECs). When non-activated, the proliferative response to WT pAECs was greater than to GTKO pAECs (P < 0.05). There was an increase in the PBMC response when the pAECs were activated by IFN-γ, the response to WT pAECs again being significantly greater than to GTKO pAECs (P < 0.01) . The study illustrates how inflammation can increase the immune response to a xenograft. (CPM = counts per minute; SI = stimulation index). (Reproduced with permission from ref. [106]). b Thrombin activates T cell proliferation. The degree of activation of GTKO pig PBMCs by thrombin was comparable to that resulting from stimulation of the cells by porcine interferon-gamma (pIFN-γ). Thrombin-stimulated activation of the human cellular response was reduced by the addition of hirudin, confirming that thrombin was the stimulatory factor. (Reproduced with permission from ref. [97])