Lymphocyte migration into tissue: the paradigm derived from CD4 subsets.

The appropriate recirculation and migration of naive, effector and memory T cells into inflamed tissue are precisely controlled by adhesive interactions with vascular endothelium. Analyses of CD4 lymphocytes have indicated that naive and antigen-experienced cells exhibit distinctive patterns of homing and recirculation, and that subsets of cells preferentially localize in different anatomical locations as a consequence of previous antigen exposure and differences in adhesion receptor usage.