The liver supports CD8⁺ T cell priming with rapid activation of antigen-specific CD8⁺ T cells.

<p>(A) To determine how early CD8⁺ T cells are activated in the liver, 4×10⁶ Thy1.1⁺OT-1⁺CD8⁺ T cells were adoptively transferred into naïve Thy1.2⁺ C57BL/6 mice and then mice were infected with 5×10⁸ PFU Ad-OVA via either SubQ or IV administration one day later. At 4, 6, and 24 hours p.i., liver and Ig LN cells were isolated and the expression of CD69 by antigen specific CD8⁺ T cells (Thy1.1⁺OT-1⁺CD8⁺ gated) and endogenous CD8⁺ T cells (Thy1.1⁻CD8⁺ T cells) was analyzed by flow cytometry. The 0 hour data points indicate control mice that received PBS administration. Data are representative of at least two independent experiments. (B) 2×10⁶ CFSE labeled Thy1.1⁺OT-1⁺CD8⁺ T cells were adoptively transferred into either splenectomized or sham control Thy1.2⁺ C57BL/6 mice treated with Mel-14 Ab one day prior to adoptive transfer. The recipient mice were then infected with 5×10⁸ PFU Ad-OVA via IV administration one day later after adoptive transfer. At 48 hours p.i., liver, spleen, and IgLN cells were isolated and the expression of CD25 by proliferating Thy1.1⁺CD8⁺ T cells was analyzed by flow cytometry. The plots are gated on Thy1.1⁺CD8⁺ T cells and the numbers represent the percentage of cells within the indicated gates.