Replacement of fiber and penton RGD sequences from ChAdOx1 with corresponding sequences from HAdV-5 fails to improve magnitudes of T cell and antibody responses.
BALB/c mice (5/group) were vaccinated intramuscularly with 108 infectious units (ifu) HAdV-5, ChAdOx1, or ChAdOx1 chimeric vectors expressing Photinus luciferase. (A) Luciferase expression in vivo was measured by bioluminescence imaging 6 h, 24 h, 4 days, 8 days and 14 days post vaccination. Graph shows mean total flux units per second (p/s) ± range. Statistical analysis performed by repeating measures two-way ANOVA with Bonferroni post test. Dagger (†) indicates statistical significance between HAdV-5 and ChAdOx1, ChAdOx1 Ad5F and ChAdOx1 Ad5RGD; hash (#) indicates significance between HAdV-5 and ChAdOx1 Ad5F+RGD; and asterisk (*) indicates significance between ChAdOx1 and ChAdOx1 Ad5F+RGD. (B,C) After 14 days post vaccination, (B) splenic CD8+ T cell responses against dominant Luc160–168 epitope GFQSMYTFV were measured by IFN-γ ELISpot and (C) anti-luciferase IgG titers were assessed in serum by endpoint ELISA. Statistical analyses in (B,C) performed by one-way ANOVA.