Migration and T-lymphocyte effector function

The development of immunity depends upon the capacity of responding T cells to become mobilized from lymphoid tissues where they are primed to sites of antigen exposure, wherever they occur in the body. Activation-induced alterations in the ability of T cells to migrate signify a fundamental change in biological function. Considerable attention is now focused on identifying mechanisms that regulate the migration and persistence of T cells that disseminate to non-lymphoid compartments as effector cells, and those that are retained in the lymphoid compartment. There are many unanswered questions about the developmental relationships and roles in protective immunity of antigen-experienced T cells that partition in different tissues.