sessions with common themes from different days for ease of reading. Lymphocyte Activation Lanzavecchio (Switzerland) talked about the life cycle of dendritic cells and T cell activation and the steps that control the generation of effector and memory T cells. He made the distinction between central and memory T cells. Central memory cells are able to re-enter lymph nodes and re-stimulate dendritic cells. He demonstrated that in the primary immune response different T cell response (TH 1, TH 2) are generated by modulating the state of activation of dendritic cells and the duration of the DC-TC interaction. Nicole Succu-Foca Cortesini (USA) presented data on the age-old issue of suppressor cells. She demonstrated a population of CD8+ CD28- cells which are class I restricted. Antigen presenting cells exposed to these suppressor cells become tolerogenic. She studied mRNA from cells exposed and not exposed to suppressor cells, and demonstrated that many genes are suppressed including cell survival, co-stimulation, transcription, activation and adhesion genes. She also stressed the problem of translating mouse experimental results to the human since in mice tolerance is transferred by CD4+ cells. Chimerism And Tolerance An interesting clinical study was reported by Trivedi et al (India). They used GM-CSF to mobilise bone marrow cells of the donor and then infused these cells into the recipient of living related renal transplant recipients in an attempt to create chimerism and tolerance. There were 120 patients in the treated group and 100 in the control group. The graft survival and patient survival