Figure 2. Intrarectal immunization induces α4β7, but not CCR9, on Ag-specific CD8⁺ T cells.

C57BL/6 mice were immunized intracolorectally or i.p. with SIINFEKL OVA peptide, and 6 d later, CD8⁺ T cells from iliac lymph nodes or spleen were analyzed for staining by the SIINFEKL-H-2K^b tetramer to determine Ag specificity and for α4β7-integrin (left) or CCR9 (right). Bars represent means ± sem. For α4β7, the difference between intracolorectal and i.p. immunization was significant (P = 0.007), whereas there was no significant difference between i.p. and intracolorectal immunization for CCR9. This experiment is representative of 2 experiments with similar results.