Fig. 3.

RA negatively regulates LC development. a RA suppresses langerin⁺ cell (BM-LC) generation in vitro, while the RAR antagonist BMS493 enhanced BM-LC generation. For BM-LC culture, BM cells were cultured in GM-CSF and TGFβ1 for 3 days in the presence of At-RA (0.01, 0.1, 1 and 10 nM) or BMS493 (100 nM) in media containing charcoal-treated or regular FBS. Frequencies of indicated CD11c⁺ cells are shown in graphs. b Defective BM-LC generation from BM cells of ∆Rara^CD11c mice. BM cells were cultured in a medium containing charcoal-treated FBS. c Confocal fluorescent microscopy of langerin expression by CD11c⁺ BM cells cultured in the LC-inducing condition without and with RA (1 nM). d Expression of Rara mRNA by CD11c⁺ BM cells cultured in the LC-induction condition without or with RA (1 nM). Normalized values for a housekeeping gene (GAPDH) are shown. Representative and combined data (n = 3–8) from at least 3 experiments are shown. *Significant differences from control or between indicated groups by one-way ANOVA with Bonferroni multiple comparisons (a) or Mann–Whitney U test (p < 0.05, unpaired, 2-sided, b, d). Error bars are defined as s.e.m