The previous experiments rely on the immune recognition of capsid proteins and do not address the capacity of these modified vectors to transduce cells and direct expression of the delivered antigen-encoding transgenes in vivo. To test the capacity of our hexon-modified vectors to deliver and induce expression of the HIV Gag transgene, we measured the expansion of Gag-specific CD8 T-cells at various consecutive time points following vaccine priming and boosting, and later measured persistence of memory T cells. Equal amounts of viral particles were used to immunize mice. Blood was collected from mice on 21 d.p.p. and 26 d.p.b. Tcells were subjected to Gag tetramer staining. The results in Figure 9 illustrate that after mouse immunization with Ad5/ HVR2-MPER-L15(Gag) (5.63%) or AdCMVGag (4.05%) we observed comparable Gag responses between these immunization groups, this is an acceptable result in that the data shows that there was not a loss of Gag response due to the incorporation of MPER epitope within the hexon capsid. Mouse immunization with Ad5 vector resulted in background levels of T-cell activation (0.83%). In addition, Ad5/HVR2-MPER-L15(Gag) (9.51%) vector allowed boosting of the Gag transgene expression as compared to the AdCMVGag vector (2.25%) (Figure 9 ), these results were statistically significant at p,0.03. Intracellular IFNc staining in tetramer positive CD8 T cells was observed for all groups (data not shown), confirming the functional integrity of the expanded HIV Gag-specific CD8 T cells.