title: Stat signals release activated naive Th cells from an anergic checkpoint.
abstract: Activation of naive Th lymphocytes by the TCR and the costimulatory molecule, CD28, is believed to provide competent signals for differentiation to effector cells. Such activated cells proliferated and expressed IL-2, but arrested in an immature state maintained by CTLA-4. Although unresponsive to restimulation by TCR/CD28 alone, restimulation with TCR/CD28 and either Stat4- or Stat6-mediated cytokine signals rescued cells to proliferate and differentiate to the appropriately matched canonical Th subsets. Addition of IL-4 at defined periods revealed that naive T cells were receptive to IL-4-mediated differentiation for up to 3 days after their initial priming. A Stat-dependent anergic checkpoint between clonal expansion and effector cell differentiation may defer the cytokine profile to be instructed at the site of infection, thus preventing the unregulated development of potentially damaging effector cells.
authors.affiliation: Howard Hughes Medical Institute and Department of Medicine, University of California-San Francisco, 521 Parnassus Avenue, San Francisco, CA 94143-0654, USA.
authors.forename: Markus
authors.initials: M
authors.lastname: Mohrs
authors.forename: Dee A
authors.initials: DA
authors.lastname: Lacy
authors.forename: Richard M
authors.initials: RM
authors.lastname: Locksley
mesh_terms: D000818:Animals; D018106:CD28 Antigens / Q000502:physiology; D002454:Cell Differentiation / Q000235:genetics / Q000276:immunology; D002455:Cell Division / Q000235:genetics / Q000276:immunology; D017635:Clonal Anergy / Q000235:genetics / Q000276:immunology*; D016207:Cytokines / Q000502:physiology; D004268:DNA-Binding Proteins / Q000172:deficiency / Q000235:genetics; D007249:Inflammation / Q000276:immunology; D007399:Interphase / Q000235:genetics / Q000276:immunology; D008213:Lymphocyte Activation / Q000235:genetics; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D011948:Receptors, Antigen, T-Cell / Q000502:physiology; D018121:Receptors, Cytokine / Q000502:physiology; D050797:STAT4 Transcription Factor; D050800:STAT6 Transcription Factor; D015398:Signal Transduction / Q000235:genetics / Q000276:immunology*; D016176:T-Lymphocyte Subsets / Q000166:cytology* / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000166:cytology* / Q000276:immunology*; D018417:Th1 Cells / Q000166:cytology / Q000276:immunology; D018418:Th2 Cells / Q000166:cytology / Q000276:immunology; D015534:Trans-Activators / Q000172:deficiency / Q000235:genetics
chemical_list: D018106:CD28 Antigens; D016207:Cytokines; D004268:DNA-Binding Proteins; D011948:Receptors, Antigen, T-Cell; D018121:Receptors, Cytokine; D050797:STAT4 Transcription Factor; D050800:STAT6 Transcription Factor; C494091:Stat4 protein, mouse; C494100:Stat6 protein, mouse; D015534:Trans-Activators