Figure 4.

Over-activation and IFN-γ production of perforin^−/− T cells induced by Fas^−/− DCs after adoptive transfer. (A) CD45.1 mice were injected with CFSE-labeled WT or perforin^−/− OT1 or OT2 cells, followed by injections of WT or Fas^−/− DCs pulsed with corresponding OVA peptides at the footpad. Three days later, draining lymph node cells were analyzed by flow cytometry. CD8⁺CD45.2⁺ OT1 cells or CD4⁺CD45.2⁺ OT2 cells were gated to determine CFSE dilution. Average numbers of cell division (mean ± SD) were plotted. **P < .01, *P < .05, n = 5. (B) CD45.1 mice were injected with WT or perforin^−/− OT1 or OT2 cells, followed by injections of WT or Fas^−/− DCs pulsed with corresponding OVA peptides as in panel A at the footpad. Three days later, draining LN cells were stained with PE–anti-CD4 or anti-CD8 and FITC-CD45.2, followed by intracellular staining with APC-anti–IFN-γ and flow cytometry. **P < .01 (n = 5). (C) CD45.1 mice were injected with WT or perforin^−/− NK cells, followed by injections of WT or Fas^−/− DCs at the footpad. Three days later, IFN-γ staining in CD45.2⁺DX5α⁺ NK cells from draining LN was analyzed (n = 5).