Fig. 2.

Calcium/NFAT pathway is impaired in both β4- and β3-deficient CD4 T cells. (A and D) The calcium response of CD4 T cells from β4-deficient (mut/mut) or β3-deficient (β3 KO) mice and WT littermate was evaluated by using 2C11 anti-CD3 Ab and goat anti-hamster (GAH) in a cross-linking system. (B and E) Calcium response of WT and β4- or β3-deficient CD4 T lymphocytes upon stimulation with thapsigargin (1 μM) under physiological Ca²⁺ concentrations (B) or in Ca²⁺ add-back experiments (E). (C) Western blot assay was performed on cytoplasmic (cyto.) and nuclear (nucl.) extracts prepared from β4 mutant CD4 T cells and control littermate stimulated for 48 h in the presence of human IL-2. Actin was used as internal control. (F) Analysis of β3-deficient CD4 T cells for NFAT nuclear translocation, using Western blot, after 18 h of TCR stimulation. Results are representative of five (A and D), three (B, C, and E), and two (F) independent experiments.