Antibody-producing donor B cells associate with increased DC secretion of IL-23 in PLNs and skin. HCT was carried out with BALB/c recipients as described in Figure 1. (A) Day 40 after HCT, percentage of CD11b⁻CD11c⁺ DC in PLNs and skin. Representative patterns and means ± SE of the percentage of CD11b⁻CD11c⁺ cells in PLNs and skin are shown. N = 4 from at least 2 replicate experiments. (B-C) Frozen PLN (B) and skin (C) sections from BALB/C recipients given TCD-BM and WT or IgH^μγ1 CD25⁻-SPL cells were stained with anti-CD11c (green), anti-IL23 (red), DAPI (blue, nucleus) 40 days after HCT. Photomicrographs (original magnification, ×400 for PLN; original magnification, ×600 for SKIN) representative of 4 replicate experiments are shown. (D) Means ± SE of IL-23 mRNA expression by PLNs and skin of recipients 40 days after HCT. Gene expression was normalized within each sample to the housekeeping gene GAPDH. N = 3 from 3 replicate experiments (**P < .01, ***P < .001).