Some hints concerning the shape of T-cell receptor structures

Several models are proposed for T-cell antigen receptor (TCR) assembly and structure. However, there is little experimental data favouring directly either one or the other(s). The minimal complex appears to be composed of a TCRαβ/CD3δe,γe/ζ2 structure but at the cell membrane, multimers of this minimal structure may be formed. Quantitative cytofluometry has suggested three CD3e chains for two TCRβ (or TCRδ) chains/complex. Such data should be repeated with monoclonal antibodies (MoAb) against extracellular (EC) parts of CD3δ or CD3γ chains. In the present review, we have compared the TCR/CD3 assembly of pre-TCR, TCRγδ and TCRαβ containing complexes, and analysed the reactivity of antibodies (Abs) against the EC part of CD3δ chains. Our data suggest an alternative assembly pathway and structure of TCR/CD3 complexes.