Cross-presentation of chemokine fusion vaccines requires TAP-1 machinery. Immature DCs (A) or splenocytes (B) derived from TAP-1 KO or wild-type C57BL/6 mice were incubated with either MIP3α-gp100 or the gp100 protein alone and tested for their ability to stimulate gp100-specific T cells derived from pmel-1 mice. Control APCs were treated with the active gp100 peptide, hgp100_25-33, or irrelevant A20 peptides. IFN-γ release was measured in the supernatants of cells cultured for 24 hours by enzyme-linked immunosorbent assay (ELISA). The data shown are representative of 1 experiment of 3 independent experiments that yielded similar results. Data are average of triplicate wells; error bars represent SD of the mean.