Identification of CTL Epitopes on Efflux Pumps of the ATP-Binding Cassette and the Major Facilitator Superfamily of Mycobacterium tuberculosis

Figure 3

Immune activity of peptide-induced CTLs in vitro was determined with intracellular cytokine staining (ICS) assay and LDH assay. CTLs were induced in vitro with peptide-loaded DCs from three healthy PPD⁺ donors and three PPD^- donors. T cells were stimulated three times at weekly intervals, and rhIL-2 (50 U/mL) and rhIL-7 (10 ng/mL) were added at intervals of 2 days. On day 21, the induced T cells were collected and their IFN-γ secretion and lysis activity were measured with intracellular cytokine staining (ICS) and LDH assays. (a) Typical flow chart for each group of PPD⁺ and PPD^- donors. (b) Statistical results of ICS assay for each peptide (). (c) LDH assay (). Peptide-loaded T2A2 cells were used as the stimulated cells and target cells. PBS group was the negative control; PHA was used as the positive control. Statistical significance was determined with Student’s -test. , , and represent the significance of the differences between the PPD⁺ donors and PPD^- donors. ^#, ^##, and ^### represent the significance of the differences between the peptide-treated groups and the PBS group.

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