Figure 6. Nasal DCs present antigen to CD4⁺ T cells and induce proliferation of allogeneic T cells in a mixed leukocyte reaction (MLR).

(a) Nasal DCs from C57BL/6 mice were expanded with B16-FLT3L cells for ten to fourteen days before sorting. Nasal APCs were sorted into two subsets: CD11c⁺MHCII⁺ F4/80⁻CD64⁻ cells, indicated as nose DCs and CD11c⁺MHCII⁺F4/80⁺CD64⁺ cells indicated as nose ϕ. Sorted cells were cultured in the indicated DC:T cell ratio for 5 days with CFSE-labeled splenic OT-II cells (left) or BALB/c splenic T cells (right). Spleen DCs were used as the positive control and spleen B cells were used as the negative control. Representative flow cytometry plots comparing the proliferation of Vα2⁺CD4⁺ T cells (left) or allogeneic T cells (right) by nasal DCs and ϕ. Cumulative data from one of three experiments is shown here. Error bars = SD. (b) Quantification of the number of proliferated (CFSE^lo) OT-II T cells (left) or Balb/c T cells (right). Cumulative data from one of three experiments is shown here. Error bars = SD.