Attenuated TCR-mediated signaling in γδ^– × hδTg thymocytes. (A) Phosphotyrosine immunoblots of total cell lysates from WT and γδ^– × hδTg thymocytes (left), or AND TCR transgenic WT and γδ^– × hδTg thymocytes (right), unstimulated (time 0) or stimulated with anti-CD3 and anti-CD4 antibodies for the times indicated. The identities of some of the induced phosphoproteins were determined by immunoblotting with specific antibodies, as shown for Cbl-1 and LAT in the lower panels. (B) Calcium mobilization and (C) phosphorylated (active) MAPK (pERK, pJNK, and pp38) induction in thymocytes stimulated with cross-linked anti-CD3 and anti-CD4 antibodies. Fold activation of each MAPK relative to unstimulated (time 0) cells is indicated. Protein loading was assessed with antibodies to total ERK, JNK, and p38.