TNF-ALPHA, RANTES, AND MCP-1 ARE MAJOR CHEMOATTRACTANTS OF MURINE LANGERHANS CELLS TO THE REGIONAL LYMPH-NODES

We have previously reported that lymph node cells generated chemotacti c factors for Langerhans cells (LCs) in the induction phase of contact dermatitis. In order to clarify the chemotactic factors involved in m igration to the regional lymph nodes, we investigated the migratory ac tivity of murine LCs toward several cytokines and chemokines in vitro. One-day cultured LC-enriched epidermal cells were added to the upper compartment of a modified Boyden chamber and cytokines were added to t he lower compartment. We counted dendritic cells migrated to the lower chamber as LCs under phase contrast microscopy. About 99% of migrated dendritic cells were positively reacted with anti-Ia(d) and NLDC145 a ntibodies and considered to be LCs. We could detect LC migration more accurately by this direct examination than by counting the migrated ce lls in the filter membrane of a Boyden chamber. In our system, migrati on of murine epidermal LCs was stimulated by TNF-alpha, RANTES and MCP -1, but not by GM-CSF, IL-1 beta, IL-4, and IL-6. TNF-alpha induced LC migration at concentrations from 4X10(3) U/ml to 5x10(4) U/ml. RANTES at concentrations from 10 to 100 ng/ml and MCP-1 at a concentration o f 100 ng/ml induced LC migration in a dose-dependent manner. These dat a confirmed that TNF-alpha, RANTES, and MCP-1 induced LC migration fro m epidermis during contact sensitization.