Loading specificity. CTL response generated by various AAV vectors against an HM1.24-positive autologous target. Shown are CTL responses of 3 donors (each experiment performed in quadruplicate) at the top and a compilation of the results from all 3 donors below. Error bars indicate standard deviation from the mean in all figures. These data demonstrate the cytotoxic response resulting from the indicated AAV vector loading techniques in a fully autologous system. Target cells were generated by the introduction of the HM1.24 gene into autologous PBLs 4 days before the CTL assay, as described in “Materials and methods.” Equivalent encapsidated genomes of the indicated vectors were used to load the DCs. Note that T cells stimulated by lysate (mock-infected, no virus)–loaded DCs, wild-type (wt) AAV-loaded DCs, AAV/Neo-loaded DCs, or AAV/E7/Neo-loaded DCs did not kill HM1.24-positive targets. However, T cells stimulated by AAV/HM1.24/Neo-loaded DCs did kill HM1.24-positive target cells. These data strongly suggest high antigen-loading specificity of the CTLs generated by AAV/HM1.24/Neo infection of DCs.