Mature DCs in murine lymph nodes are more susceptible to glucocorticoid killing than immature DCs during experimental asthma. (A) Triple immunostaining of CD11c (green), MHC II (red), and caspase 3 (blue) was performed on mediastinal lymph node sections as described in “Methods” and in Figure 1. Merged images contain staining for all 3 antigens and show that the majority of the caspase 3⁺ cells (red arrows) are mature DCs. Scale bar, 20 μm. (B) OVA treatment increased the number of DCs (± SD) in mediastinal lymph nodes. Approximately 150 (CON and DEX groups) to 900 (OVA and OVA+DEX) cells per animal (n = 6 per group) were counted across 3 to 12 sections. (C) DEX induced caspase 3 activation more efficiently in mature DCs than in immature DCs (*significantly greater than CON, P < .01; 1-way ANOVA followed by Tukey posthoc test).