Expression of the protease gene HF as a marker in rejecting allogeneic murine heart transplants.

Phenotypic characterization of the inflammatory infiltrate often provides very little information about the fate of a transplant. Therefore we decided to look for functional markers, characteristic for activated effector cells involved in the rejection of primarily vascularized MHC-mismatched heart transplants in mice. Infiltrating cells in the interstitium of eventually rejected allogeneic heart transplants were found to express the gene for the serine esterase HF (granzyme A) in high numbers already on day 2 following transplantation, whereas HF mRNA positive cells were absent, or only rarely found, in syngeneic nonrejecting transplants throughout the entire observation period of 10 days after transplantation. These findings could also become of importance for the prediction of the outcome of organ transplants in humans.