TSLP-DC induce IL-21 and CXCL13 production through OX40L. (A) FACS analysis of surface expression of CD86, PDL1, ICOSL, and OX40L by DCs cultured without any stimulation (NT), TSLP, or LPS for 48 h. Filled gray histogram shows matched isotype control. Black histogram shows antibody staining. One representative donor is shown. (B) Quantification of MFI as in A. Mean ± SEM for seven experiments. (C) Quantification of cytokine by CBA (IL-3 and IL-10) or ELISA (CXCL13 and IL-21) by CD4 T cells differentiated during 6 d with DCs or TSLP-DC. Anti-ICOSL blocking antibody or isotype control antibody (25 µg/ml) were kept all along the culture. Mean ± SEM for four experiments, is plotted. D) Cells were cultured as in C, and instead of ICOSL blocking antibody, an anti-OX40L antibody or isotype control (50 µg/ml) were used. Mean ± SEM for seven experiments. *, P < 0.05; **, P < 0.01; ***, P < 0.001, paired Student’s t test.