title: The Erk2 MAPK regulates CD8 T cell proliferation and survival.
abstract: The magnitude of T cell responses is determined by proliferation and survival decisions made by the responding cells. We now demonstrate that the Erk MAPK pathway plays a critical role in these cell fate decisions within CD8 T cells. While Erk1 is dispensable for all aspects of CD8 T cell activation, Erk2 is required for the proliferation of CD8 T cells activated in the absence of costimulation. Surprisingly, Erk2 is not required for proliferation following the addition of a costimulatory signal in vitro, or upon viral infection in vivo, but regulates the size of the responding population by enhancing cell survival. An important component of this Erk2-derived signal is the transcriptional regulation of Bcl-2 family members Bcl-x(L) and Bim, and impaired Erk2-deficient CD8 T cell survival can be rescued by genetic ablation of Bim. These studies ascribe multifaceted functions specific to Erk2 in CD8 T cell activation, proliferation, and survival.
authors.affiliation: Department of Cellular and Molecular Medicine, Division of Biological Science, Molecular Biology Section, University of California, San Diego, La Jolla, CA 92093, USA.
authors.forename: Warren N
authors.initials: WN
authors.lastname: D'Souza
authors.forename: Chiung-Fang
authors.initials: CF
authors.lastname: Chang
authors.forename: April M
authors.initials: AM
authors.lastname: Fischer
authors.forename: Manqing
authors.initials: M
authors.lastname: Li
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Hedrick
mesh_terms: D000818:Animals; D051017:Apoptosis Regulatory Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D000072224:Bcl-2-Like Protein 11; D018414:CD8-Positive T-Lymphocytes / Q000201:enzymology / Q000276:immunology*; D049109:Cell Proliferation; D002470:Cell Survival / Q000235:genetics / Q000276:immunology; D008213:Lymphocyte Activation / Q000235:genetics / Q000276:immunology*; D020935:MAP Kinase Signaling System / Q000235:genetics / Q000276:immunology*; D008565:Membrane Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D019950:Mitogen-Activated Protein Kinase 1 / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D014158:Transcription, Genetic / Q000235:genetics / Q000276:immunology; D051020:bcl-X Protein / Q000235:genetics / Q000276:immunology / Q000378:metabolism
chemical_list: D051017:Apoptosis Regulatory Proteins; D000072224:Bcl-2-Like Protein 11; C494812:Bcl2l1 protein, mouse; C000606776:Bcl2l11 protein, mouse; D008565:Membrane Proteins; D011518:Proto-Oncogene Proteins; D051020:bcl-X Protein; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3