TCR stimulation leads to nuclear translocation of β-catenin.

<p>(A) T cells were stimulated with plate bound anti-CD3/CD28 in the presence or absence of 20 mM LiCl for 18 hours, as indicated, following which cytoplasmic and nuclear fractions were separated. Fractions were immunoblotted for β-catenin and phospho-β-catenin expression. Cytoplasmic and nuclear fractionation was confirmed by tubulin (cytosol) and lamin-B1 (nuclear) expression. (B) T cells were stimulated with anti-CD3/CD28 magnetic beads for the indicated times. CD25 (IL-2Rα) mRNA levels were measured by qRT-PCR, using Abl1 as an internal control, to verify successful T cell activation. (C) The expression of the TCF/β-catenin target gene <i>Axin2</i> was measured by qRT-PCR following stimulation of T cells with anti-CD3/CD28 (same samples as in B). (D) In parallel to the samples in B and C, T cells and HEK293T cells were left untreated or incubated with 20 mM lithium for 7 hours and measured for Axin2 mRNA levels relative to those of Abl1. (E) Left: T cells were stimulated with anti-CD3/CD28 for the indicated times and Axin2 and DKK-1 mRNA levels were determined by qRT-PCR relative to Abl and PPIA. The expression relative to Abl1 is shown, with calculations relative to PPIA yielding comparable results. Right: HEK293T cells were left untreated or incubated with 20 mM lithium for 7 hours and measured for DKK-1 mRNA levels relative to those of Abl1. All qRT-PCR reactions were performed in triplicate.