Restoration of abated T cell stimulation activity of mature dendritic cells

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.