Fig. 3.

Migration of Clone 4 CD8⁺ T cells to the pancreas of irradiated InsHA mice depends on CD4 help. (A) Irradiated InsHA mice were injected with either 5 × 10⁶ CFSE-labeled naive HNT Thy1.1⁺ CD4⁺ T cells, 5 × 10⁶ CFSE-labeled naive Clone 4 Thy1.1⁺ CD8⁺ T cells, or a combination of 5 × 10⁶ Clone 4 CD8⁺ T cells and 5 × 10⁶ HNT CD4⁺ T cells. Mice were killed on days 7, 10, or 13 after transfer and the presence of CD8⁺ Thy1.1⁺ and CD4⁺ Thy1.1⁺ donor T cells in the pancreas was evaluated by FACS. Numbers indicate FACS event counts in the depicted gates. (B) Cells from the pancreas were either stimulated with K^d HA peptide or left untreated and IFN-γ production was assessed by intracellular staining. Plots represent CFSE fluorescence versus IFN-γ on gated CD8⁺ Thy1.1⁺ lymphocytes. The percentages of IFN-γ secreting CD8⁺ donor T cells are indicated. (C) Expression of CD44, CD62L, and CD25 markers on gated CD8⁺ Thy1.1⁺ lymphocytes in the pancreas is shown at days 10 and 13. Shaded histograms show isotype controls. Data from 1 representative experiment of 5 are presented.