Cutting edge: rapid accumulation of epidermal CCL27 in skin-draining lymph nodes following topical application of a contact sensitizer recruits CCR10-expressing T cells.

CC chemokine receptor 10 and its ligand, CCL27, are important components of T cell-mediated cutaneous immunity, but whether they influence lymph node (LN) homing by T cells is unknown. In this study, CCL27 protein was detected in skin-draining LN by Western blotting and ELISA although CCL27 mRNA transcripts were low. CCL27 protein was present at higher levels in skin-draining LN compared with gut-draining LN and spleen. A single topical treatment of mouse skin with the contact sensitizer 2,4-dinitro-1-fluorobenzene (DNFB) resulted in a 13-fold increase in CCL27 protein accumulation in skin-draining LN within 1 h and a 5-fold elevation in CCR10 mRNA (normalized to the T cell marker CD2) within 6 h. DNFB treatment also resulted in rapid depletion of approximately 75% of CCL27 from the epidermis. In summary, we describe a novel mechanism for the recruitment of CCR10-positive T cells to skin-draining LN following the rapid release of preformed CCL27 from the epidermis.