The role of ICAM-1 molecule in the migration of Langerhans cells in the skin and regional lymph node

Abstract

ICAM‐1 (CD54) plays an important role in the cell‐cell interaction and migration of leukocytes. Previous studies have shown that ICAM‐1 is involved in inflammatory reactions and that a defect in ICAM‐1 gene inhibits allergic contact hypersensitivity. This study indicates that the migration of hapten presenting Langerhans cells into the regional lymph nodes was significantly reduced in ICAM‐1‐deficient mice compared to wild‐type C57BL/6 mice. The reduced number of dendritic cells in regional lymph nodes did not result from abnormal migration of Langerhans cells into the skin of ICAM‐1‐deficient mice. The concentration and distribution of Langerhans cells in the naïve skin of ICAM‐1‐deficient mice was equal to that of wild‐type mice. Following hapten sensitization, Langerhanscell migration out of the skin and recruitment of fresh Langerhans cells back to the epidermis was not affected in ICAM‐1‐deficient mice. Further experiments demonstrated that ICAM‐1 deficiency on lymphatic endothelium rather than on dendritic cells was responsible for the reduced migration of Langerhans cells into draining lymph nodes. This study indicates that ICAM‐1 regulates the migration of dendritic cells into regional lymph nodes but not into or out of the skin.