Figure 1

Analysis of the signaling signature and functional effects of sAbs and iAbs stimulation. A-D) Purified human T cells were treated with either soluble (sAbs) or immobilized (iAbs) CD3xCD28 mAbs for the indicated time periods. Total cell lysates (A, B, and D) or TCRζ immunoprecipitates C) were prepared and analyzed by Western blotting using the indicated Abs. One representative immunoblot of at least 3 independent experiments is shown. The phosphorylation of TCRζ was quantified using the 1D ImageQuant software and the values were normalized to the corresponding total TCRζ signal. Data represent the mean of the phosphorylation levels shown as arbitrary units ± SEM of 3 independent experiments. E) T cells were labeled with CFSE and stimulated as indicated. Proliferation was assessed after 72h by analyzing CFSE content on a FACS Calibur. One representative experiment of three independent experiments is shown.