Figure 7. Characterization of CD4⁺ and Tetramer⁺CD4⁺ cell populations in the spleen of WT mice during early and late P. chabaudi malaria.

(A) Numbers of CD4+ cells per spleen, spontaneous CD4+ cell proliferation and IFN-γ production on days 0, 4, 7, 10, 15, 20 and 30 of infection. Data represent the means ± SD (n = 6–10). CD4+ cell proliferation is represented as percentages of replicating (CFSE^low) cells. Intracellular and secreted IFN-γ was quantified in gated CD4⁺ cells and in 72-h supernatants, respectively. (B) iRBC-stimulated CD4+ cell proliferation and IFN-γ production in the same groups of mice (n = 6–10). CD4+ cell proliferation is represented as percentages of replicating (CFSE^low) cells. Secreted IFN-γ was quantified in 72-h supernatants. (C) Dot plots showing gated CD4⁺ cells that recognise CD1d-α-GalCer tetramers (Tetramer⁺ cells). Numbers in dot plots represent the means ± SD (n = 6) of the percentages of Tetramer⁺ cells in gated CD4⁺ cells. (D) Numbers per spleen of Tetramer⁺CD4⁺ cells and Tetramer⁺CD4⁺IFN-γ cells on days 0, 7, 10, 15 and 20 of infection. Data represent the means ± SD (n = 6). In A, B and C, *, p<0.05, infected mice compared with non-infected mice. Data are representative of three experiments.