In situ effector mechanisms in rat kidney allograft rejection. II. Heterogeneity of the effector cells in the inflammatory infiltrate vs that in the spleen of the recipient rat.

We have isolated the infiltrating inflammatory cells from rejecting rat kidney allografts via collagenase-DNase dispersion and 1g velocity sedimentation. A representative cell sample, devoid of blood contamination and subclass-specific cell losses, is thus obtained in a functionally viable state. The infiltrating inflammatory cells display an immunologically specific in vitro cytotoxicity to donor-strain lymphoblasts. The peak cytotoxicity takes place in the graft before it takes place in the lymphatic system of the recipient rat. The allograft-infiltrating cytotoxic cells display a far wider distribution profile in 1g velocity than do the recipient spleen killer cells. The donor-strain lymphoblasts are highly sensitive to the lytic effect of both allograft-infiltrating and spleen killer cells, but the transplant parenchymal cells, consisting mainly of tubular and glomerular cells, are relatively insensitive. The findings suggest heterogeneity of the effector cells in the allograft infiltrate vs that in the spleen, and indicate that different structures of the target organ are differently sensitive to cellular cytotoxicity.