Prereceptor amplification of corticosterone increases apoptosis of pDCs. (A) H6pdh+/+ and H6pdh−/− pDCs were cultured overnight in normal media alone (+0) or in the presence of 10−7 M 11-dehydrocorticosterone (+A) or 10−7 M corticosterone (+B) ± CpG 2216 at 2 µM before evaluation of cell viability by Annexin V and propidium iodide (PI) staining. (A) Representative flow cytometric plots showing Annexin V and PI staining (± CpG 2216). (B) Summary data showing viability of H6pdh+/+ and H6pdh−/− pDCs as a percentage of control cultures without addition of A or B or CpG. (Left) pDC viability in the presence of A or B in the absence of CpG. (Middle) Viability of H6pdh−/− (CD45.2) and H6pdh+/+ (CD45.1) pDCs when cultured together at a 1:1 ratio in the presence of A or B but in the absence of CpG. (Right) pDC viability in the presence of CpG and either A or B. Data derived from 2 to 3 independent experiments. (C) Mean ± SD IFN-α levels detected in culture supernatants of H6pdh−/− or H6pdh+/+ littermate-derived pDCs following 18 hours of exposure to nil or to CpG 2216 in the presence or absence of 10−7 M A or 10−7 M B. Data derived from 3 independent experiments (n = 3 per group).
