title: Antigen-induced unresponsiveness results in altered T cell signaling.
abstract: Pretransplant exposure to allogeneic lymphocytes can result in donor-specific unresponsiveness and prolonged allograft survival. Intracellular signaling events have been described in anergic T cell clones, but the biochemical events underlying in vivo induced unresponsiveness have not been studied in detail. We employed a TCR transgenic mouse, bearing the 2C TCR, providing adequate numbers of homogenous peripheral T cells to study biochemical aspects of T cell unresponsiveness in vivo. 2C mice exposed to semiallogeneic lymphocytes (H-2b x H-2d) experienced prolonged H-2d cardiac allograft survival, and cells from these mice did not proliferate or make IL-2 in response to alloantigen (H-2d). Importantly, there were marked differences in TCR-associated tyrosine phosphorylation activation patterns. The targets for the unresponsive state appear to be diminished Lck activation and absent ZAP-70 and LAT (linker for activation of T cells) phosphorylation. Our study demonstrates that Ag-induced tolerance in vivo is accompanied by altered early TCR-mediated signaling events.
authors.affiliation: Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA. dianne_mdkay@macmailgw.dfci.harvard.edu
authors.forename: D B
authors.initials: DB
authors.lastname: McKay
authors.forename: H Y
authors.initials: HY
authors.lastname: Irie
authors.forename: G
authors.initials: G
authors.lastname: Hollander
authors.forename: J L
authors.initials: JL
authors.lastname: Ferrara
authors.forename: T B
authors.initials: TB
authors.lastname: Strom
authors.forename: Y
authors.initials: Y
authors.lastname: Li
authors.forename: S J
authors.initials: SJ
authors.lastname: Burakoff
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D006085:Graft Survival / Q000235:genetics / Q000276:immunology; D007108:Immune Tolerance / Q000235:genetics; D007275:Injections, Intravenous; D007519:Isoantigens / Q000008:administration & dosage / Q000276:immunology*; D008198:Lymph Nodes / Q000166:cytology / Q000276:immunology; D008213:Lymphocyte Activation / Q000235:genetics; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D010766:Phosphorylation; D019000:Phosphotyrosine / Q000378:metabolism; D011948:Receptors, Antigen, T-Cell / Q000235:genetics / Q000502:physiology; D015398:Signal Transduction / Q000235:genetics / Q000276:immunology*; D013154:Spleen / Q000166:cytology / Q000276:immunology / Q000637:transplantation; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism / Q000502:physiology; D018631:ras Proteins / Q000502:physiology
chemical_list: D007519:Isoantigens; D011948:Receptors, Antigen, T-Cell; D019000:Phosphotyrosine; D018631:ras Proteins