Comment in:

Nat Immunol. 2005 Sep;6(9):866-8.

Chemokine receptor CCR7 guides T cell exit from peripheral tissues and entry into afferent lymphatics.

Center for Immunology and Inflammatory Diseases, Division of Rheumatology, Allergy and Immunology, Massachusetts General Hospital, Harvard Medical School, Charlestown, Massachusetts 02129, USA.

T cell circulation between peripheral tissues and the lymphoid compartment is critical for immunosurveillance and host defense. However, the factors that determine whether T cells remain in peripheral tissue or return to the circulation are undefined. Here we demonstrate that the chemokine receptor CCR7 is a critical signal that determines T cell exit from peripheral tissue. Both CCR7(-) and CCR7(+) effector T cells entered mouse asthmatic lung and while CCR7(-) T cells accumulated, CCR7(+) T cells continued to migrate into afferent lymph. Delivery of both CCR7(+) and CCR7(-) T cells directly into the airways showed that only CCR7(+) T cells exited the lung and entered draining lymph nodes. Our study establishes a molecular basis for T cell exit from peripheral tissues.

PMID: 16116469 [PubMed - indexed for MEDLINE]