Figure 7. Human lung CD1c⁺ DCs expand CD103⁺CD8⁺ T cells via TGF-β.

Sorted DCs were cocultured with CFSE-labeled allogeneic naïve T cells at a 1:100 ratio in the presence or absence of TGF-β1 Ab blockade as indicated. At day 6, CFSE⁻CD8⁺ T cells were analyzed for CD103 expression by flow cytometry. (A) Representative Scatter plots showing CD103 expression on CFSE⁻CD8⁺ T cells cocultured with CD1c⁺ DCs in the presence of 100 μg/ml of TGF-β neutralizing Abs or isotype control. (B–E) Percentages of CD103-expressing CFSE⁻CD8⁺ T cells and percentages of CFSE⁻CD8⁺ total T cells in cocultures with DC subsets isolated from the lungs of humanized mice (B) human lungs (C) in the presence of titrated doses of TGF-β neutralizing Abs or TGF-βRI kinase inhibitor (D). One representative experiment of more than three is shown (one-way ANOVA with Bonferroni post-test). Data are shown as mean ± SEM. (E) The same type of experiment as in (B) but DCs are sorted from the draining LNs of humanized mice. (F) Scatter plots illustrated CD103 expression on CFSE⁻CD8⁺ T cells cocultured with CD141⁺ DCs in the presence of recombinant human TGF-β1.