FIG. 6.
MPT59/Ag85B peptide 25-specific T helper cytokine production by CD4+ T cells in IL-10−/− mice. IL-10−/− mice with a B6 background received a single dose of 200 μl of control vehicle (cream only; open bars), 104 CFU of live M. avium subsp. paratuberculosis in cream (hatched bars), or 104 CFU of heat-killed M. avium subsp. paratuberculosis in cream (solid bars) and were maintained under otherwise germfree conditions. CD4+ T cells from the MLN and PP of the mice were purified and cultured at a density of 5 × 106 cells/ml with peptide 25 (1 μg/ml) for 3 days along with 106 cells/ml of γ-irradiated APCs. Cytokine production by these ex vivo Ag-stimulated T helper cells was determined by ELISA. The data presented are the mean IL-4, TNF-α, and IFN-γ secretions (pg/ml) ± SD for quadruplicate cultures. Asterisks indicate statistically significant differences, i.e., P < 0.01, compared to controls. Groups consisted of 15 mice each, and experiments were repeated three times.