A recombinant therapeutic agent which is chemically identical to or similar to CD40-ligand. CD40-ligand, also known as CD40L/TRAP and CD154, is a type II membrane protein which binds to CD40, a cell surface receptor that belongs to the tumor necrosis factor receptor family; CD40 is expressed on B lymphocytes, monocytes, dendritic cells (DC), hematopoietic progenitors, endothelial cells and epithelial cells. Recombinant CD40-ligand may be used to activate DC ex vivo via CD40 binding; CD40-ligand-activated DC may provide or augment a protective antitumor immunity when administered in dendritic cell cancer vaccines.