Figure 2

Self-processing polyproteins to reconstruct the TCR:CD3 complex. (A) Schematic diagram of the TCR:CD3 complex spanning the cytoplasmic membrane. The T-cell receptor (TCR) is formed by two subunits and the other four proteins assemble in three dimers to form the CD3 complex. The square boxes in the cytoplasmic sequences of the CD3 subunits represent the immunoreceptor tyrosine-based activation motifs (ITAMs). (B) To express the TCR:CD3 complex in cells, two retroviral vectors were designed to carry the two ORFs drawn here [8]. In the retrovirus encoding the four CD3 subunits, three different 2A sequences were used to avoid deletions due to direct repetitions.