The cytoplasmic tail of the T cell receptor ζ chain is required for signaling via CD26

Abstract

The protease dipeptidylpeptidase IV (CD26) provides an alternative activation pathway for T lymphocytes and is involved in several aspects of T cell function. Activation via CD26 requires the expression of the T cell receptor (TcR)/CD3 complex. Here we have investigated the role of the TcR ζ chain for T cell activation via CD26. T cell hybridomas expressing TcR with various deletions in the CD3 ζ chain were transfected with a CD26 cDNA and the response of the transfected cells to anti‐CD26 monoclonal antibodies was tested. Our data show that the ζ chain is essential and that at least one YXXL motif in the cytoplasmic tail of the ζ chain is required for CD26‐mediated signaling. Other TcR components do not replace the ζ chain.