Macrophage Inflammatory Protein 3α Is Expressed at Inflamed Epithelial Surfaces and Is the Most Potent Chemokine Known in Attracting Langerhans Cell Precursors

• Published in: The Journal of experimental medicine Vol. 192; no. 5; pp. 705 - 718
• Main Authors: Dieu-Nosjean, Marie-Caroline, Massacrier, Catherine, Homey, Bernhard, Vanbervliet, Béatrice, Pin, Jean-Jacques, Vicari, Alain, Lebecque, Serge, Dezutter-Dambuyant, Colette, Schmitt, Daniel, Zlotnik, Albert, Caux, Christophe
• Format: Journal Article
• Language: English
• Published: The Rockefeller University Press 05.09.2000
• Subjects: macrophage inflammatory protein 3^a; Original
• ISSN: 0022-1007; 1540-9538; 1892-1007
• DOI: 10.1084/jem.192.5.705

Dendritic cells (DCs) form a network comprising different populations that initiate and differentially regulate immune responses. Langerhans cells (LCs) represent a unique population of DCs colonizing epithelium, and we present here observations suggesting that macrophage inflammatory protein (MIP)-3α plays a central role in LC precursor recruitment into the epithelium during inflammation. (a) Among DC populations, MIP-3α was the most potent chemokine inducing the selective migration of in vitro–generated CD34+ hematopoietic progenitor cell–derived LC precursors and skin LCs in accordance with the restricted MIP-3α receptor (CC chemokine receptor 6) expression to these cells. (b) MIP-3α was mainly produced by epithelial cells, and the migration of LC precursors induced by the supernatant of activated skin keratinocytes was completely blocked with an antibody against MIP-3α. (c) In vivo, MIP-3α was selectively produced at sites of inflammation as illustrated in tonsils and lesional psoriatic skin where MIP-3α upregulation appeared associated with an increase in LC turnover. (d) Finally, the secretion of MIP-3α was strongly upregulated by cells of epithelial origin after inflammatory stimuli (interleukin 1β plus tumor necrosis factor α) or T cell signals. Results of this study suggest a major role of MIP-3α in epithelial colonization by LCs under inflammatory conditions and immune disorders, and might open new ways to control epithelial immunity.