FIG. 1.

Immunogenicity of DNA vaccination with in vivo EP. Groups of BALB/c mice (four animals/group) were immunized with 50, 5, or 0.5 μg of the DNA vaccine expressing Env IIIB gp120 alone or with caliper EP or needle EP. Cellular and humoral immune responses were assessed by D^d/P18 tetramer binding assays at multiple time points after immunization (A) and by Env pooled peptide and P18 epitope peptide IFN-γ ELISPOT assays (B). Env pooled peptide and P18 epitope peptide IFN-γ/IL-2 CD8⁺ intracellular cytokine staining assays (C) and Env-specific ELISAs (D) were performed at week 4 after immunization in mice that received the 50-μg dose of the DNA vaccine with or without needle EP.