A Study of T Cell Tolerance to the Tumor-Associated Antigen MDM2: Cytokines Can Restore Antigen Responsiveness, but Not High Avidity T Cell Function
Figure 4
CTL from Agpos mice display defects at the level of cytotoxic effector function that can most effectively be rescued by IL-2.
Splenocytes from Agneg mice and Agpos mice were stimulated for 3 days in vitro with pMDM100-coated targets in the presence of 10 U/ml IL-2, 10 ng/ml IL-7, 50 ng/ml IL-15 or 50 ng/ml IL-21. (A) CD43 expression levels on the stimulated T cells was analysed by surface staining and flow cytometric analysis. Numbers in histograms represent the specific MFI of the gated CD8+Vβ7+ population. (B) Granzyme B expression levels on the stimulated T cells was analysed by intracellular staining and flow cytometric analysis. Numbers in histograms represent the specific MFI of the gated CD8+Vβ7+ population. Following staining with an appropriate isotype control mAb the MFI of the gated CD8+Vβ7+ T cells from the Agneg mice and Agpos mice was 398 and 495, respectively. Data in A and B are representative of three independent experiments. (C) Cytolytic activity of stimulated T cells against MDM2-expressing MBL-2 tumor cells and RMA-S targets coated with pMDM100 peptide (10 µM) or a class I binding control peptide, pSV9 (10 µM). Data are representative of two independent experiments.