Immunogenicity of GAd adenoviral vectors encoding CT26 nAgs. A, Schematic representation of GAd adenoviral vectors: Six immunogenic nAgs (#4, #5, #11, #18, #23, #28), including both CD4 (in blue) and CD8 (in red) reactivities, selected from the previously published GAd-31 vaccine (12), were cloned to generate different GAd-6 multi-epitopes (constructs 1–4) or GAd mono-epitope vectors (constructs 5–6). WT, wild-type. B,Ex vivo IFNγ ELISpot showing Ag-specific immune responses following naïve mice immunization with the indicated GAd vaccines. Results are expressed as mean + S.E.M. of spot forming cells (SFC) per million of splenocytes (n = 6 mice/group). Positive and negative responses are indicated with + and −, respectively, according to criteria of positivity described in the Materials and Methods section. Data are representative of three independent experiments.