FIG. 6.

Analysis of VSV-specific T-cell responses induced in vivo by injection of DNAs encoding either naked or VSV-G-pseudotyped Gag particles. Groups of five mice were injected with 100 μg of either pCMV.ΔR8-2 + pCMV.AS DNA (left panel) or pCMV.ΔR8-2 + pCMV.VSV (right panel) DNA into normal muscle. Two weeks after DNA immunization, ex vivo ELISPOT assay was performed on splenocytes to measure VSV-specific IFN-γ-secreting T cells. Splenocytes were incubated for 40 h with wild-type vaccinia virus (rvv WT) or with recombinant vaccinia virus expressing VSV-G (rvv VSV) at an MOI of 1/1. The ELISPOT assay was performed on undepleted, CD4⁺ T-cell-depleted, and CD8⁺ T-cell-depleted splenocytes. The number of IFN-γ SFC is expressed per 10⁶ splenocytes.