Freshly isolated and cultured mature dendritic cells (DQ rapidly lose their
high capacity to activate T cells. This diminished T cell activation activ
ity is due, in part, to dramatically reduced expression of the costimulatio
n ligands B7-1 (CD80) and B7-2 (CD86). Here we show that cultivation of mat
ure DC with the lymphokines TNF alpha, GM-CSF, or TNF alpha plus GM-CSF, fu
lly restored and enhanced their T-cell stimulation activity by two to three
fold, four to fivefold, or six to sevenfold, respectively. The restored T-c
ell stimulation activity was directly correlated with induced and increased
levels of CD80 (16-fold) and CD86 (10-fold) expression by the lymphokine-c
ultured DC. These results should facilitate many current DC-vaccination eff
orts towards generating more potent T cell responses. (C) 2001 Academic Pre
ss.