Figure 5.

Vaccination with Twist induces antigen-specific T-cell responses in TRAMP mice. A, C57BL/6 and TRAMP mice (n=5) harboring moderately-differentiated adenocarcinomas at average age of 17 weeks were not treated or were vaccinated with 1 YU of Twist-vaccine on days 0, 7, and 14. On day 28, mice were sacrificed, spleens were harvested, and CD4⁺ T cells were purified and tested for proliferation by culturing with irradiated APCs and Twist peptide (5 µg/mL) or LCMV control peptide (5 µg/mL) or ConA positive control (10 µg/mL) for 5 days. Proliferation in response to stimuli was measured by incorporation of ³H-thymidine, which was added during the final 18 h. Statistical analyses were done by Student’s t-test. Error bars indicate mean ± S.E.M. from triplicate measurements. B, to evaluate CD8⁺ T-cell responses, spleens were harvested and coincubated for 7 days with Twist peptide (1 µg/mL). Lymphocytes were restimulated with fresh irradiated naive splenocytes and each peptide: 1 µg/mL of Twist peptide or 1 µg/mL or HIV-gag peptide. Twenty-four hours later, the supernatant fluid was collected and analyzed for murine IFN-γ using the Cytometric Bead Array kit. Nonspecific IFN-γ production in response to HIV-gag control peptide was subtracted from that induced by Twist peptide. Data are from two separate independent experiments.