Induction of antigen-specific immunosuppression by CD95L cDNA-transfected 'killer' dendritic cells

Dendritic cells (DCs) are special subsets of antigen-presenting cells chara cterized by their highly potent capacity to activate immunologically naive T cells. Here we report that DCs that are transfected with CD95 ligand (CD9 5L) cDNA, called 'killer' DCs, deliver death signals, instead of activation signals, to T cells after antigen-specific interaction. Injection of antig en-pulsed killer DCs into mice before sensitization induced antigen-specifi c immunosuppression. When administered after sensitization, killer DCs supp ressed immune responses almost completely after subsequent challenge. Thus, killer DCs represent an entirely new immunomodulatory protocol, which may become directly applicable in preventing and even treating T cell-mediated inflammatory diseases.