HHD II mice immunizations with rMVA. Splenocytes from HHD II mice immunized with rMVA were subjected to IVS and then tested for lytic function in a standard CRA. Filled symbols show killing of T2 cell targets loaded with a pp65 or IE peptides; open symbols indicate killing of the same target cells loaded with p53_149-157. Each set of experiments was repeated at least twice. (A) Lytic activity of splenocytes from 2 mice immunized with 10⁷ IU or (B) 2 × 10⁷ IU of pp65/pp150-MVA, against targets loaded with (closed symbols) pp65_495-503 or (open symbols) p53_149-157. (C) UbRIE4-MVA (5 × 10⁷ IU) was used to immunize 2 mice. Filled symbols represent individual mouse recognition of IE1_297-306–loaded targets, and open symbols indicate background lysis of targets loaded with p53_149-157. In panels D and E, 3 mice were immunized with a mixture of 2.5 × 10⁷ IU pp65/pp150-MVA and 2.5 × 10⁷ IU UbRIE4-MVA. Splenocytes from each spleen were stimulated separately with (D) pp65_495-503 (filled symbols) and (E) IE1_297-306 (filled symbols). In panels D and E, open symbols indicate background lysis to p53_149-157. At E/T, 20 significant differences (P < .05) were detected between the activity against p53_149-157 and pp65_495-503 (D) and between p53_149-157 and IE1_297-306 (E), according to the Welch 2-sided t test.