Figure 4.

Marked expansion of the hMAGE-A3-specific CD8⁺ T-cell population following MG1-MAGEA3 boost.

(A,B) Kinetics of CD8⁺ T-cell responses against hMAGE-A3 in 20 macaques treated with Ad-MAGEA3:MG1-MAGEA3. Response is displayed both as the count (cells per µl of blood; A) and as the frequency (% among total CD8⁺ T-lymphocytes; B) of IFNγ-producing CD8⁺ T-lymphocytes. Histograms represent mean ± SD. p-value (Dunn’s test) considered non significant (NS) when > 0.05; *p < 0.05, **p < 0.01. (C-E) Illustrations of the three different kinetics of the boost response witnessed across the vaccinated macaques. (F, G) Peak CD8⁺ T-cell boost responses against hMAGE-A3 in each individual macaque, ranked according to their magnitude with bottom 10 and top 10 responders respectively displayed in the panels F and G. (H, I) Corresponding MG1-MAGEA3 boost responses expressed as the frequency (%) of reactive cells inside the total CD8⁺ T-cell population. (C-I) Sub-responses to each of the nine pools of hMAGE-A3 peptides used for antigenic re-stimulation are color-coded: pool of peptides 1–10 in red, 11–20 in white, 21–30 in pink, 31–40 in green, 41–50 in blue, 51–60 in yellow, 61–70 in purple, 71–80 in orange and 81–87 in grey. (J) Fold by which hMAGE-A3-reactive CD8⁺ T-cell population expanded between day 0 and the peak response day following MG1-MAGEA3 boost. In the absence of any detectable prime response in AM2w-lo 2, its boost fold was arbitrarily set to 200. Red dashed line illustrates boost fold of 1 (i.e. failure of MG1 boost). Green dotted line and dashed line illustrate median and mean boost folds, respectively. hMAGE-A3, human melanoma-associated antigen, family A, member 3; IFNγ, interferon gamma.