INTERLEUKIN-1 BUT NOT TUMOR-NECROSIS-FACTOR-ALPHA SYNERGISTICALLY UP-REGULATES THE GRANULOCYTE-MACROPHAGE COLONY-STIMULATING FACTOR-INDUCEDB7-1 EXPRESSION OF MURINE LANGERHANS CELLS

Epidermal Langerhans cells (LC) express several co-stimulatory molecul es such as B7/BB1, which has been implicated as one of the important d eterminants for potent antigen-presenting function of LC. Recent studi es have shown that B7/BB1 antigens comprise three distinct molecules t ermed B7-1, B7-2 and B7-3. Previous studies have revealed that the phe notypic and functional properties of murine LC are enormously affected by various cytokines including granulocyte-macrophage colony stimulat ing factor (GM-CSF), interleukin-1 (IL-1), and tumour necrosis factor alpha (TNF-alpha) derived from surrounding keratinocytes. We have alre ady demonstrated that the expression of B7-1 of murine LC is significa ntly enhanced by GM-CSF, IL-1 or TNF-alpha. In this paper, we present that IL-1, but not TNF-alpha, synergistically up-regulates the GM-CSF- induced B7-1 expression of murine LC.