FIG 4.

Cellular immune responses to Ad5-PAopt. Mice were intramuscularly vaccinated with Ad5-PAopt, Ad5-EGFP, or rPA, and splenocytes were harvested at indicated times and restimulated in vitro with NA-9 for intracellular cytokine staining and ELISPOT IFN-γ assay. (A) Intracellular IFN-γ assay at week 2 after vaccination. (B) Intracellular TNF assay at week 2 after vaccination. (C) ELISPOT IFN-γ assay for examining the maintenance of the cellular immune response. The data are presented as the means ± SEM (n = 6 per group). rPA+Alum, rPA protein with aluminum adjuvant; SFCs, spot-forming cells.