A high-affinity alloreactive endogenous TCR contributes to low frequencies of TCR-transduced CD8+ T cells in vivo. (A) A total of 1 × 106 TCR-transduced transgeneic 2C T cells (B6 background) were mixed with 10 × 106 TCR-transduced transgeneic DsRed T cells (B6 background) and adoptively transferred into either established allogeneic (B6 → B10A) or syngeneic (B6 → B6) transplant recipients late after HCT. Frequencies of transferred DsRed+GFP+ T cells (top row) or 2C+GFP+ T cells (bottom row) in peripheral blood (PBL), spleen (SPL), lymph node (LN), and BM were determined. Black bars represent allogeneic recipients; and white bars, syngeneic recipients. *P < .05. **P < .01. ***P < .001. Values are mean ± SD. (B) Splenocytes harvested on day 1 after AT were gated on 2C+GFP+ T cells and consecutively analyzed for annexin V expression (left panel). Equally (middle and right panel), DsRed splenocytes were gated on GFP+CD8+ T cells and analyzed for CD95L and CD95 expression. P = not significant (n.s.) between either group.
