Protective immunity by an engineered DNA vaccine for Mayaro virus
Fig 4
scMAYV-E induces a robust antigen specific cellular immune response to multiple epitopes in mice.
C57BL/6 mice were immunized with 25 μg of either pVax1 empty vector or scMAYV-E plasmid once and euthanized 2 weeks later, or three times at 2-week intervals then euthanized one week after the last immunization. Splenocytes were harvested and cultured overnight in the presence of linear peptide pools spanning the full-length envelope protein. (A) IFN-γ ELISpot assay used to measure IFN-γ-producing spot-forming units (SFUs) generated per 106 splenocytes +/- SEM. IFN-γ ELISpot assay performed on splenocytes from immunized animals after ex vivo stimulation with matrix peptide pools spanning the (B) E1 protein or (C) E3+E2 proteins. Average IFN-γ SFUs generated per 106 splenocytes +/- SEM for each peptide pool shown. The immunodominant epitopes in E1 and E3+E2 identified via the matrix peptide pools are indicated with arrows.