Alf Hamann (Universitatmedizin Charite, Berlin, Germany)

• Specific trafficking - which cells, which function?; lymphocyte traffic to lymphoid and non-lymphoid organs in different species is regulated by several mechanisms; the multistep paradigm and the control of lymphocyte trafficking - homing to mucosal tissues as a model; adhesion molecules and the regulation of the migration of lymphocytes; chemokines as regulators of leukocyte adhesion and migration; the ontogeny of lymphocytes and homing to the thymus; roles of a4b7 and aEb7 integrins in the interactions of lymphocytes with the intestinal mucosa; T cell trafficking to skin - a paradigm for tissue-selective lymphocyte homing; lymphocyte trafficking through the central nervous system.