Induction of AID from naive B cells.

Highly purified adult CD20⁺CD27⁺, CD20⁺CD27⁻, or CB B cells at the cell numbers of 0.5 × 10⁶ cells were cultured with medium alone (lanes 1, 4, 7), 0.01% SAC, 50 U/mL IL-2, 50 ng/mL IL-10, and 1 μg/mL anti-CD40 cross-linked with CD32T for 1 day (lanes 2, 5, 8) or 4 days (lanes 3, 6, 9). After extraction of total RNA, RT-PCR was performed as described in “Materials and methods.” Each template contained the same of cDNA from RNA extracted from highly purified B cells. The C lanes represent control of contamination-free reaction, in which all PCR reagents are present, but there is no cDNA. The β₂-microglobulin (β₂-MG) was used as a positive control. Data are representative of the results of 3 experiments using different donors.