Figure 3.

Impact of decreased activation-induced deaminase (AID) levels in heterozygotes on isotype switching. (a) Diagram depicts the order of switch regions in the murine immunoglobulin locus. (b) Resting/naïve B cells were pooled from two or three AID wild-type (WT) and three or four heterozygous (Het) MRL/lpr mice at 10–12 weeks of age and activated with indicated cytokines and supernatants collected at 72 hr: IL-4, interleukin-4; TGF-β, transforming growth factor-β; IFN-γ, interferon-γ. The experiment was repeated three times. (c) Cells were pooled and treated with lipopolysaccharide (LPS) alone or plus cytokines for different times as indicated for four AID wild-type and four AID heterozygous MRL/lpr mice at 10–12 weeks of age. Supernatants were collected at multiple time-points as depicted and each treatment was repeated twice. Error bars represent standard errors.