Journal of Leukocyte Biology Volume 58. September 1995 317 Migration of distinct subsets of CD8 blood T cells through endothelial cell monolayers in vitro

Abstract: The immune response in many infections and to allografts is dependent on CD8 cytotoxic T lympho-cytes (CTh). Influx of CD8 Cli from the blood has been documented during antigen challenge. We have pre-viously found that a subset of CD8 T cells from normal blood can migrate through endothelial cell monolayers in vitro. To further characterize migration-prone CD8 T cells from normal blood, we examined the expression of CD28 and a restricted epitope of CD18/CD11a (S6F1), a CTL marker. Although normal blood T cells were heterogeneous in their expression of CD28, three populations could be identified (CD28b0, CD28te, and CD28ligl). CD8 cells migrating across endothelial cell monolayers were enriched for CD8t+ CD28”” cells and a subset of CD8Cim+ cells, which were high Both adherent and migrating CD8 cells were exclusively (>95%) lugh There was also preferential adhesion and migration of CD8 cells expressing the low-molecu-lar.weight form of the leukocyte common antigen, CD45RO. Cytokine activation ofthe endothelium did not significantly alter preferential migration of these subsets. These data suggest that certain subsets of CD8 memory T cells in normal human blood are prone to, adhere to, and migrate through allogeneic endothelial cells and would thus be likely to be recruited to sites of antige