Lipidated pp65_495-503 peptide stimulates a cytotoxic immune response in HLA A2.1 transgenic mice. Mice were immunized with 50 nmol of either pp65_495-503 peptide without lipid attached, one lipid attached, or two lipids attached together with the PADRE HTL peptide (20 μg) with or without IFA adjuvant. After 12 days mice were killed, spleens were removed, and the spleen cells restimulated as described in Materials and Methods for two cycles. A CRA was performed on all spleen cell suspensions at an E:T = 20. p53 and pp65 peptides were pulsed onto T2 cells, pp65 and wt Vacs were used to infect JY cells, and MRC-5 HLA A*0201 fibroblasts were either infected with HCMV AD169 (Fibro-CMV) or not (Fibro) as the targets for the CRA.