Transcriptional regulation of Ca_o²⁺-induced CD83 expression on human B cells. (A) Time course of CD83 gene expression (as determined by RT-PCR) in isolated B cells cultured in AIM-V for 0, 30, 60, or 120 minutes. The example is representative of 5 additional samples. (B) Effects of transcriptional and translational inhibitors on CD83 expression. Isolated B cells were cultured for 1 hour in AIM-V alone (Ø) or with actinomycin D (Act) (100 ng/mL) or cycloheximide (CHX) (100 μM) prior to total RNA extraction and RT-PCR (i) and PBMCs were cultured for 4 hours prior to flow cytometric analysis of CD83 expression in B cells (CD19⁺-gated PBMCs) (ii). (C) Effects of plasma and albumin on CD83 expression. (i) Purified B cells were cultured in AIM-V with plasma or HSA for 1 hour prior to RNA extraction and RT-PCR. (ii) Flow cytometric analysis of CD83 on B cells (gated on CD19⁺ cells in PBMC populations) cultured for 4 hours in AIM-V with 30% autologous plasma, HSA (50 mg/mL), or rHA (50 mg/mL). The data shown are representative of 7 different experiments.