Cellular response against PR and RT induced by ID and IM DNA immunization assessed by FluoroSpot.

<p>Immune recognition of the peptides representing CD4⁺ and CD8⁺ epitopes of PR (A, B) and RT (C, D) by FluoroSpot test assessing in vitro production of IFN-γ (A, C) and IL-2 (B, D) in mice immunized with the plasmid encoding inactivated PR of HIV-1 HXB2 in pVax1 vector mixed with pVaxLuc (A, B); plasmid encoding inactivated RT of HIV-1 HXB2 in pVax1 vector mixed with pVaxLuc (C, D). Cytokine response to the immunodominant CTL epitope of Luc (LucP) in PR/Luc, RT/Luc and control empty vector/Luc DNA immunized mice (CTRL) is presented everywhere for comparison. Mice (n = 5 per group) were immunized as described in the legend to <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0197902#pone.0197902.g001" target="_blank">Fig 1</a> and their responses were assessed on experimental end-point at day 21 by INF-γ/IL-2 FluoroSpot. Data represent the average number of spot forming cells registered per million splenocyte per group (n = 5) with SE. Statistical comparison was done using Mann-Whitney U-test; *<i>p</i> < 0.05; **<i>p</i> < 0.01; ***<i>p</i> < 0.001; ****<i>p</i> < 0.0001.