Figure 2. Effect of TCDD on the CD40L-induced mRNA expression of plasmacytic differentiation regulators in human B cells.

Freshly isolated human B cells (1 × 10⁶/ml) were treated with TCDD at concentrations indicated or vehicle (VH), or remained untreated (NA) as a vehicle control and then co-cultured with irradiated CD40L-L cells (1.5 × 10³ cell/well) in the presence of recombinant human IL-2 (10 U/ml), IL-6 (100 U/ml), and IL-10 (20 ng/ml) for 4 days. Cells were transferred to new culture plates in the absence of CD40L-L cells on Day 4 and cultured for three additional days. Cells were harvested on Days 1, 4, 6, and 7, total RNA was isolated using RNeasy Kit, and steady state mRNA levels of (A) Blimp-1 and (B) Pax5 were measured by Taqman real-time PCR and normalized to endogenous 18S ribosomal RNA. Data are presented as fold change compared to the VH treated group on Day 1. Data are representative of two separate experiments (each experiment used B cells from one individual donor) with 3 experimental replicates per group.