Fig 2.

Flow cytometry analysis of IFN-γ-producing spleen cells following B. melitensis infection. Wild-type, RAG^−/−, TAP-1^−/−, MHC-II^−/−, and MuMT^−/− C57BL/6 mice were injected i.p. with PBS (as a control) or 4 × 10⁴ CFU of B. melitensis and sacrificed at the indicated times. Spleen cells were harvested and analyzed by flow cytometry. Cells were gated according to size and scatter to exclude dead cells and debris from the analysis. Spleen cells from individual mice were first analyzed for forward size scatter (FSC) versus IFN-γ production and then for cell surface markers. The frequency of IFN-γ-positive cells in uninfected deficient mice was similar to the one observed in uninfected wild-type mice. (A) Number of IFN-γ-positive cells per 1.5 × 10⁶ spleen cells acquired. Each piece of data represents the value obtained from an individual spleen, and the data are representative of two independent experiments. Gray bars represent the medians. cont, control; *, P < 0.05; ***, P < 0.001. (B) IFN-γ-positive cells in each group were then analyzed for CD3, CD4, CD8, and NK1.1 expression. The data represent the mean ± SEM of groups described in panel A. (C) The percentages of IFN-γ-positive cells 12 days p.i. are represented in a sectoral diagram according to cell surface markers.