Dynamic Changes in the Immunophenotypic Maturation Status of CD19 B Lymphocytes in Patients with Acute Cellular Rejection after Heart Transplantation

lymph nodes, spleen) and days (2, 5). Results: DCs morphology & numbers: the number in the allograft was slightly higher at day 2 and much higher at day 5 compared to the isograft. Also, the morphology in the allograft was matured while that in the isograft was immatured. Interestingly, administration of CTLA4-Ig in allograft results in optimized maintenance of DCs morphology and numbers compared to no treated allograft. DCs-T cell interplay: There was no interaction in isograft. In allograft, CD8 (blue) and CD11c (EYFP) cellular interactions were observed for at least 5 minutes on Day 2 at graft. Although the same interaction was observed in CTLA4-Ig treated allograft recipient, cross talk between cells (CD11c EYFP and CD4/8) didn’t last longer compared to allograft. Validation: FACS was performed on day 5. 1) Increased CD11c cells at graft/para-aortic lymph nodes and 2) increased Yae cells in allograft compared to isograft. Conclusions: We investigated the role of recipient DC-T cell interaction in graft rejection versus tolerance utilizing “state-of-the-art” imaging technologies. Its results will provide invaluable insight into temporal and spatial interplay of cellular interactions in determining the choice between tolerance and rejection.