Fig. 8. Gut-aGVHD induced by IFNγ−/−CD8+ T cells is associated with depletion of donor-type CX3CR1hi MNP via PD-1.
Gut-aGVHD was induced in BALB/c recipients with grafts from WT or IFNγ−/− C57BL/6 donors as described in Fig. 4a. a Ten days after HCT, colonic lamina propria mononuclear cells were analyzed for percentage and yield of donor-type CD11c+CD11b+CX3CR1hi MNP. Representative patterns and means ± SEM of percentage and yield are shown. n = 8. b CX3CR1hi and CX3CR1lo MNP from recipients given WT and IFNγ−/− CD8+ T cells are shown in histogram of PD-1 staining; one representative pattern is shown for n = 5 in each group. c Apoptosis of CX3CR1hi MNP from the recipients given WT or IFNγ−/− CD8+ T cells was measured by Annexin V staining. A representative staining pattern and means ± SEM of percentage of Annexin V+ cells are shown. n = 5. d Recipients given IFNγ−/− CD8+ T cells were treated with anti-PD-L1 mAb or control IgG (400 µg/mouse) on days 0, 3, and 6 after HCT. On day 10, the percentages of CX3CR1hi MNP and percentages of Annexin V+ CX3CR1hi MNP were measured. One representative staining pattern and means ± SEM are shown. n = 4 (% Annexin V+), 10 (%CX3CR1hi). e Recipients given IFNγ−/− CD8+ T were treated with anti-IL-22 mAb or control IgG (150 µg/mouse) every other day from days 0 to 6 after HCT. On day 10, the yield of CX3CR1hi MNP and their expression of PD-1 were measured. Means ± SEM of percentage of CX3CR1hi MNP and MFI are shown. n = 10. All results are combined from two replicate experiments; each dot represents one mouse, unpaired two-tailed Student’s t test was used to compare means between two groups. a **p = 0.0039, ****p < 0.0001; c **p = 0.0033; d **p = 0.0045, ***p = 0.0007.