Figure 1. Expression kinetics of plasmacytic differentiation regulators in human B cells activated with CD40L.

Freshly isolated human B cells (1 × 10⁶/ml) were 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 d. 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, 2, 3, 4, 5, 6, and 7, total RNA was isolated using RNeasy Kit, and steady state mRNA levels of IgJ, Igu, Blimp-1, Pax5 and BCL6 were measured by Taqman real-time PCR and normalized to endogenous 18S ribosomal RNA. Data are presented as fold change compared to Day 1. Data are representative of two separate kinetic experiments (each used B cells from one individual donor) with 3 experimental replicates per group.