Impaired capacity of antigen-specific CD4⁺ T cells to express cytokines.

<p>Groups of BALB/c and CBA mice (n = 8) were infected with <i>L. major</i> parasites for two (A and B) or four (C) weeks. Individual popliteal lymph nodes and footpads (pool from at least two footpads) were harvested and the % of cytokine-expressing CD4⁺ T cells was determined by flow cytometry. (3A) dot plot profiles of cytokine-expressing CD4⁺ T cells isolated from the popliteal lymph nodes and the footpads two weeks post infection; (3B) % of cytokine-expressing CD4⁺ T cells two weeks post infection. (3C) % of cytokine-expressing CD4⁺ T cells four weeks post infection. Error bars represent standard deviations. Isotype control for IFN-γ: 0.23±0.05%, IL-4: 0.31±0.08% and IL-10: 0.26±0.06%. All cytokines were below the detection limit when the cells were stimulated in the absence of PMA/ionomycin stimulation. The detection limits were defined as % isotype control +3 standard deviations: IFN-γ = 0.38%, IL-4 = 0.55% and IL-10 = 0.44%. Data show the results of one representative experiment out of three independent experiments.