title: Commitment to the CD4 lineage mediated by extracellular signal-related kinase mitogen-activated protein kinase and lck signaling.
abstract: The development of T cells results in a concordance between the specificity of the TCR for MHC class I and class II molecules and the expression of CD8 and CD4 coreceptors. Based on analogy to simple metazoan models of organ development and lineage commitment, we sought to determine whether extracellular signal-related kinase (Erk) mitogen-activated protein (MAP) kinase pathway signaling acts as an inductive signal for the CD4 lineage. Here, we show that, by altering the intracellular signaling involving the Erk/MAP kinase pathway, T cells with specificity for MHC class I can be diverted to express CD4, and, conversely, T cells with specificity for MHC class II can be diverted to express CD8. Furthermore, we find that activation of the src-family tyrosine kinase, p56lck is an upstream mediator of lineage commitment. These results suggest a simple mechanism for lineage commitment in T cell development.
authors.affiliation: Department of Biology, Cancer Center, University of California at San Diego, La Jolla 92093, USA.
authors.forename: L L
authors.initials: LL
authors.lastname: Sharp
authors.forename: S M
authors.initials: SM
authors.lastname: Hedrick
mesh_terms: D000818:Animals; D015704:CD4 Antigens / Q000096:biosynthesis / Q000235:genetics; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology* / Q000201:enzymology* / Q000502:physiology; D016827:CD8 Antigens / Q000096:biosynthesis / Q000235:genetics; D019070:Cell Lineage / Q000235:genetics / Q000276:immunology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D005419:Flavonoids / Q000494:pharmacology; D015395:Histocompatibility Antigens Class I / Q000235:genetics; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck) / Q000502:physiology*; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000502:physiology*; D011948:Receptors, Antigen, T-Cell / Q000096:biosynthesis / Q000235:genetics; D015398:Signal Transduction / Q000235:genetics / Q000276:immunology*; D016176:T-Lymphocyte Subsets / Q000201:enzymology / Q000276:immunology
chemical_list: D015704:CD4 Antigens; D016827:CD8 Antigens; D004791:Enzyme Inhibitors; D005419:Flavonoids; D015395:Histocompatibility Antigens Class I; D011948:Receptors, Antigen, T-Cell; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck); D020928:Mitogen-Activated Protein Kinases; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one