GLε transcript assay
The CD40-simulated activation of GLε transcription was evaluated as previously reported [33]. Briefly, 1×106 cells were stimulated overnight with anti-CD40 antibody (10 µg/ml) or an isotype control antibody, with or without 500 U/ml mouse IL-4 (BD Biosciences). RNA was isolated using Trizol (Invitrogen), and reverse-transcribed (Superscript III kit, Invitrogen). Quantitative PCR for GLε and Hprt1 was performed using SYBR GREEN master mix (Applied Biosystems), and an Applied Biosystems 7900HT Fast Real-Time PCR instrument. Expression of GLε in each sample was normalized to the expression of Hprt1.