title: Cross-antagonism of a T cell clone expressing two distinct T cell receptors.
abstract: Inhibition of T cell activation can be mediated by analogs of the original antigenic peptide (TCR antagonists). Here, a T cell clone expressing two distinct TCR was used to investigate whether such inhibition involves an active mechanism by examining whether an antagonist for one TCR could influence responses stimulated by the other TCR engaging its agonist. Our results demonstrate functional cross-inhibition under these conditions involving the ability of antagonist: TCR interactions to diminish Lck enzymatic activity associated with the agonist-recognizing second TCR, apparently through enhancement of SHP-1 association with these receptors. Our findings reveal that inhibition of cellular responses by antagonists arises at least in part from active negative regulation of proximal TCR signaling and identify elements of the biochemical process.
authors.affiliation: Section of Immunobiology, Yale University School of Medicine and Howard Hughes Medical Institute, New Haven, Connecticut 06510, USA. bonnie.dittel@yale.edu
authors.forename: B N
authors.initials: BN
authors.lastname: Dittel
authors.forename: I
authors.initials: I
authors.lastname: Stefanova
authors.forename: R N
authors.initials: RN
authors.lastname: Germain
authors.forename: C A
authors.initials: CA
authors.lastname: Janeway
mesh_terms: D000818:Animals; D047908:Intracellular Signaling Peptides and Proteins; D008024:Ligands; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck) / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D004676:Myelin Basic Protein / Q000378:metabolism; D010766:Phosphorylation; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11; D053824:Protein Tyrosine Phosphatase, Non-Receptor Type 6; D017027:Protein Tyrosine Phosphatases; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051076:Proto-Oncogene Proteins c-fyn; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000819:agonists / Q000037:antagonists & inhibitors*; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000378:metabolism*; D014443:Tyrosine / Q000378:metabolism
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D008024:Ligands; D004676:Myelin Basic Protein; D011518:Proto-Oncogene Proteins; D016693:Receptors, Antigen, T-Cell, alpha-beta; D014443:Tyrosine; D011505:Protein-Tyrosine Kinases; C494960:Fyn protein, mouse; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck); D051076:Proto-Oncogene Proteins c-fyn; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11; D053824:Protein Tyrosine Phosphatase, Non-Receptor Type 6; D017027:Protein Tyrosine Phosphatases; C516725:Ptpn11 protein, mouse; C509248:Ptpn6 protein, mouse