Loss of adoptively transferred Bg1 CD8⁺ T cells in Tie2-LacZ mice is not dependent on β-gal expression by ECs. (A) Graded numbers of CD8⁺ Bg1 cells expressing the congenic marker Thy1.1 were adoptively transferred into Thy1.2⁺ C57BL/6 or Tie2-LacZ recipient mice. At 6 days later, mice were challenged with 2 × 10⁶ pfu MCMV-LacZ, and the proliferation of Bg1 CD8⁺ T cells was determined on day 6 following immunization by staining for CD8, Thy1.1, and the transgenic Vβ7 chain. Representative data from one of 2 independent experiments are shown. (B,C) Adoptive transfer of Bg1 CD8⁺ T cells in BM chimeric mice. A total of 5 × 10⁴ (B) or 10⁵ (C) TCR transgenic Thy1.1⁺ Bg1 cells were adoptively transferred intravenously into the indicated Thy1.2⁺ BM chimeric mice. At 9 days (B) or 30 days (C) later, mice were challenged with 2 × 10⁶ pfu MCMV-LacZ, and proliferation of Bg1 CD8⁺ T cells was determined on day 6 following MCMV-LacZ challenge in the indicated organs. Values represent mean percentage (± SEM) of Thy1.1⁺Vβ7⁺ cells within the CD8 T-cell compartment.