Fig. 2. Antigen specific T cell responses against P. yoelii P36 and P52 antigens.

a Mice were immunized with the protective cocktail of DNA encoded CSP and P36/P52 and 4-8 weeks later received 2 K Py-RAS followed by liver/spleen harvest for further cellular analysis by ELISPOT and flow-cytometry as shown. b Splenocyte ELISPOT data for in vitro stimulation with CSP peptide, P36 protein, and P52 protein. c Splenocytes from immunized mice groups depicted in panel a were stimulated overnight in vitro with the P36 (i and iii) or P52 (ii and iv) proteins and were tracked through flow cytometry to identify the activation of (i–ii) CD4⁺ and (iii–iv) CD8⁺ Tcm cells using the CD69 marker. A fluorescence minus one (FMO) control was used to gate on CD69 expressing CD8⁺ and CD4⁺ T cells (S Fig. 2, panel b). To quantify T cell activation following antigen stimulation, protein antigen was not added to unstimulated wells (UN). The frequency of T cell activation following either P36 or P52 protein stimulation was compared using the graphs at the bottom of each panel using the marker CD69. N = 5 mice per group. Data is representative of two independent experiments. Data are the mean ± SEM. Data were analyzed by the Mann-Whitney test. P < 0.05 is considered significant. *P < 0.05, **P < 0.01.