CD8 Memory T cell Migration to Cardiac Allografts (145.16)

Abstract

Abstract Memory T cells that recognize donor alloantigen jeopardize the survival of life-saving organ transplants. Although recent publications studied the role of chemokines in effector T cell migration to the allograft, the migratory requirements of memory T cells are not known. Phenotyping of CD8 memory T cell populations demonstrated up-regulation of CXCR3 and CCR5 chemokine receptors. Therefore, we investigated the survival of cardiac allografts (BALB/c, H-2d) transplanted into aly mice (alymphoplastic, no secondary lymphoid organs after splenectomy, H-2b) that received sorted CXCR3-/- or wt CD8+CD44+ memory T cells (C57Bl/6, H-2b, recognizing H-2d) via adoptive transfer. Additionally, a group of mice receiving CXCR3-/- cells was treated with anti-CCR5 antibody. No significant differences in allograft survival could be detected between the groups. Furthermore, flow analysis revealed no difference in the migration of adoptively co-transferred, congenic, CFSE labeled CXCR3-/- and wt CD8+CD44+ memory T cells to the cardiac allograft at 20 hours and 3 days after cell transfer (n=6). Our results show that CD8 memory T cell migration to the allograft is independent of CXCR3 and CCR5. Moreover, the migration requirements for CD8 memory T cells clearly differ from those established for effector T cells highlighting the role of memory T cells in immune surveillance and their threat to transplanted organs.