The interchain disulfide bond between TCRαβ heterodimers on human T cells is not required for TCR-CD3 membrane expression and signal transduction

Abstract

In the present paper, it was attempted to define the amino acids or regions on TCRβ molecules that determine the TCRα-TCRβ interaction. Sequence studies on HBP-ALL variant cells with an intrinsic deficiency in TCRαβ dimer formation elucidated a conserved amino acid motif in the TCR-C(β) β-strand E, = Y(C)(L)(S)SRLR(V)(S)(A); this motif seems to represent one interaction area for the TCRα-TCRβ interaction. In addition, amino acids in the connecting peptide may be shaped in a precise structure (by the interactions with CD3 molecules?) involved in TCRα-TCRβ dimerization. This result was supported by the finding that the interchain disulfide bond between TCRα and β chains is not required for membrane expression or transmembrane signal transduction of TCRαβ-CD3 complexes. Finally, comparative results from two membrane TCR-CD3-negative Jurkat variants R4.9 and E6.E12 suggest that TCR-C(β) exon 1- and 2-encoded amino acids are important for the TCRβ-CD3γε association.