title: An oscillatory switch in mTOR kinase activity sets regulatory T cell responsiveness.
abstract: There is a discrepancy between the in vitro anergic state of CD4(+)CD25(hi)FoxP3(+) regulatory T (Treg) cells and their in vivo proliferative capability. The underlying mechanism of this paradox is unknown. Here we show that the anergic state of Treg cells depends on the elevated activity of the mammalian target of rapamycin (mTOR) pathway induced by leptin: a transient inhibition of mTOR with rapamycin, before T cell receptor (TCR) stimulation, made Treg cells highly proliferative in the absence of exogenous interleukin-2 (IL-2). This was a dynamic and oscillatory phenomenon characterized by an early downregulation of the leptin-mTOR pathway followed by an increase in mTOR activation necessary for Treg cell expansion to occur. These data suggest that energy metabolism, through the leptin-mTOR-axis, sets responsiveness of Treg cells that use this information to control immune tolerance and autoimmunity.
authors.affiliation: Laboratorio di Immunologia, Istituto di Endocrinologia e Oncologia Sperimentale, Consiglio Nazionale delle Ricerche (IEOS-CNR), Napoli 80131, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Procaccini
authors.forename: Veronica
authors.initials: V
authors.lastname: De Rosa
authors.forename: Mario
authors.initials: M
authors.lastname: Galgani
authors.forename: Luisa
authors.initials: L
authors.lastname: Abanni
authors.forename: Gaetano
authors.initials: G
authors.lastname: Calì
authors.forename: Antonio
authors.initials: A
authors.lastname: Porcellini
authors.forename: Fortunata
authors.initials: F
authors.lastname: Carbone
authors.forename: Silvia
authors.initials: S
authors.lastname: Fontana
authors.forename: Tamas L
authors.initials: TL
authors.lastname: Horvath
authors.forename: Antonio
authors.initials: A
authors.lastname: La Cava
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Matarese
mesh_terms: D000818:Animals; D015704:CD4 Antigens / Q000096:biosynthesis; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D017635:Clonal Anergy / Q000187:drug effects / Q000235:genetics; D018450:Disease Progression; D004681:Encephalomyelitis, Autoimmune, Experimental / Q000188:drug therapy / Q000276:immunology / Q000378:metabolism* / Q000503:physiopathology; D051858:Forkhead Transcription Factors / Q000096:biosynthesis; D006801:Humans; D007376:Interleukin-2 / Q000276:immunology / Q000378:metabolism; D053645:Interleukin-2 Receptor alpha Subunit / Q000096:biosynthesis; D020738:Leptin / Q000276:immunology / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D015398:Signal Transduction; D020123:Sirolimus / Q000494:pharmacology / Q000627:therapeutic use; D050378:T-Lymphocytes, Regulatory / Q000187:drug effects / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D058570:TOR Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000276:immunology / Q000378:metabolism*
chemical_list: D015704:CD4 Antigens; C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; D007376:Interleukin-2; D053645:Interleukin-2 Receptor alpha Subunit; D020738:Leptin; D058570:TOR Serine-Threonine Kinases; D020123:Sirolimus