Induction of AID mRNA in human naive B cells by CD40-L and IL-4.

Human naive B cells were cultivated in the presence of CD40-L and IL-4 for up to 8 days. The mRNA of AID (nt 200-520), bcl-6 (nt 248-547), blimp-1 (421-824), and β-actin (391-660) was amplified by PCR from cDNA pools, and the PCR products were separated by agarose gel electrophoresis and hybridized with an internal radiolabeled oligonucleotide (A). The mRNA of AID, bcl-6, and blimp-1 was measured by real-time PCR using a Light Cycler (Roche) with the primer pairs as above and normalized to the expression of β-actin mRNA (B).