Functional profile of vaccine-induced CD4 and CD8 T cells. (A) Flow cytometry profiles of CD4 T cells and CD8 T cells able to mediate degranulation activity and to secrete IL-2, IFN-γ, and TNF-α are shown. Blood mononuclear cells were stimulated with the relevant peptide pools for 16 h and stained as described in Materials and methods. The functional profiles of both CD4 and CD8 T cells were performed on blood mononuclear cells of volunteers EU11, ES02, and ES08 that were vaccinated with DNA C plus NYVAC C. Volunteers ES02 and ES08 also exhibited Gag-specific in addition to Env-specific CD4 and CD8 T cell responses. With regard to the proliferation, cells were labeled with CFSE and stimulated with the relevant peptide pools, and proliferation was measured at day 6. (B) Functional composition of CD4 and CD8 T cell responses. The results shown were generated from the determinations in 11 responders. All the possible combinations of the responses are shown on the x axis, whereas the percentages of the functionally distinct cell populations within the total CD4 and CD8 T cell populations are shown on the y axis. Responses are grouped and color-coded on the basis of the number of functions. The pie chart summarizes the data, and each slice of the pie corresponds to the fraction of CD4 or CD8 T cells with a given number of functions within the total CD4 and CD8 T cell populations. Bars correspond to the fraction of different functionally distinct T cell populations within total CD4 and CD8 T cell populations. Mean and standard errors are also shown.