Figure 8. T cell-derived CD70 inhibits allogeneic CD8⁺ T cell response.

Lethally irradiated BM1 or FVB hosts were transplanted with CD8⁺ T cells purified from naïve C57BL/6 WT or CD70^−/− mice. (A) Body weight was monitored after BM1 hosts injected with 2×10⁶ CD8⁺ T cells and 3.5×10⁶ TCD BM. Representative data from 1 of 2 experiments is shown as mean ± SD (n=5 per group), with statistical significance determined by two-way ANNOVA. (B) Kaplan-Meier survival data of BM1 hosts are combined from 2 independent experiments (n=8–9 per group). Statistical significance was determined by Log-rank test. (C–F) FVB hosts injected with 1×10⁶ CD8⁺ T cells and 3×10⁶ TCD BM and sacrificed on Day 9 or 12. (C) Absolute numbers of CD8⁺ T cells were calculated by multiplying the total numbers of spleen cells by the percentages of TCRβ⁺CD8⁺ T cells present in spleen samples determined by flow cytometry on day 12. Summary data of caspase-8 activation (D) and caspase-3 activation (E) are combined from 3 independent experiments. (F) Summary data of CTLA-4, PD-1, TIM-3, LAG-3 expression on TCRβ⁺CD8⁺ T cells at Day 9 after allo-HCT. Statistical significance was determined by unpaired student t test.