Fig. 3.

IRF5 is required for γ2a germ-line transcription upon TLR9 stimulation. Semiquantitative RT-PCR was performed for germ-line mRNA transcripts induced in Irf5^+/+ (left panels) and Irf5^−/− (right panels) purified B cells either untreated (−) or stimulated with lipid A plus IFNγ, anti-μ plus IL4 plus anti-CD40, or CpG-B for the indicated number of days. Representative gels from μ (n = 3), γ3 (n = 3), γ1 (n = 3), γ2b (n = 3), γ2a (n = 6), ε (n = 2), and α (n = 2) are shown. β-Actin (βact; n = 6) is a loading control. All signals were confirmed to be in the linear range of amplification. DNA molecular weight markers indicated in the right column from top to bottom are ≈500 (wide), 400, 300, and 200 bp.