Migration, maintenance and recall of memory T cells in peripheral tissues.

After the resolution of an immune response, antigen-specific memory T cells persist at many sites in the body. The antigen-specific memory T-cell pool includes memory T cells that preferentially reside in peripheral tissues, such as the skin, gut and lungs, where they provide a first line of defence against secondary pathogen infection. Determining how peripheral memory T cells are regulated is essential for our understanding of host-pathogen interactions and for vaccine development. In this Review, we discuss recent insights into the generation, control and recall of peripheral T-cell memory responses.