title: T cell effector function and anergy avoidance are quantitatively linked to cell division.
abstract: We have shown previously that T cells activated by optimal TCR and CD28 ligation exhibit marked proliferative heterogeneity, and approximately 40% of these activated cells fail entirely to participate in clonal expansion. To address how prior cell division influences the subsequent function of primary T cells at the single cell level, primary CD4+ T cells were subjected to polyclonal stimulation, sorted based on the number of cell divisions they had undergone, and restimulated by ligation of TCR/CD28. We find that individual CD4+ T cells exhibit distinct secondary response patterns that depend upon their prior division history, such that cells that undergo more rounds of division show incrementally greater IL-2 production and proliferation in response to restimulation. CD4+ T cells that fail to divide after activation exist in a profoundly hyporesponsive state that is refractory to both TCR/CD28-mediated and IL-2R-mediated proliferative signals. We find that this anergic state is associated with defects in both TCR-coupled activation of the p42/44 mitogen-activated protein kinase (extracellular signal-related kinase 1/2) and IL-2-mediated down-regulation of the cell cycle inhibitor p27kip1. However, these defects are selective, as TCR-mediated intracellular calcium flux and IL-2R-coupled STAT5 activation remain intact in these cells. Therefore, the process of cell division or cell cycle progression plays an integral role in anergy avoidance in primary T cells, and may represent a driving force in the formation of the effector/memory T cell pool.
authors.affiliation: Department of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors.forename: A D
authors.initials: AD
authors.lastname: Wells
authors.forename: M C
authors.initials: MC
authors.lastname: Walsh
authors.forename: D
authors.initials: D
authors.lastname: Sankaran
authors.forename: L A
authors.initials: LA
authors.lastname: Turka
mesh_terms: D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000201:enzymology / Q000276:immunology / Q000378:metabolism; D002118:Calcium / Q000502:physiology; D018797:Cell Cycle Proteins; D002455:Cell Division / Q000276:immunology; D002478:Cells, Cultured; D017635:Clonal Anergy / Q000276:immunology*; D050760:Cyclin-Dependent Kinase Inhibitor p27; D016207:Cytokines / Q000096:biosynthesis; D015536:Down-Regulation / Q000276:immunology; D004789:Enzyme Activation / Q000276:immunology; D005260:Female; D006133:Growth Substances / Q000502:physiology; D007376:Interleukin-2 / Q000502:physiology; D008213:Lymphocyte Activation / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008869:Microtubule-Associated Proteins / Q000502:physiology; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D011493:Protein Kinase C / Q000378:metabolism; D019908:Proto-Oncogene Proteins c-raf / Q000378:metabolism; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism; D015375:Receptors, Interleukin-2 / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000166:cytology* / Q000201:enzymology / Q000276:immunology* / Q000378:metabolism; D025521:Tumor Suppressor Proteins; D018631:ras Proteins / Q000378:metabolism
chemical_list: C493961:Cdkn1b protein, mouse; D018797:Cell Cycle Proteins; D016207:Cytokines; D006133:Growth Substances; D007376:Interleukin-2; D008869:Microtubule-Associated Proteins; D011948:Receptors, Antigen, T-Cell; D015375:Receptors, Interleukin-2; D025521:Tumor Suppressor Proteins; D050760:Cyclin-Dependent Kinase Inhibitor p27; D019908:Proto-Oncogene Proteins c-raf; D011493:Protein Kinase C; D020928:Mitogen-Activated Protein Kinases; D018631:ras Proteins; D002118:Calcium