title: Phosphatase PP2A is requisite for the function of regulatory T cells.
abstract: Homeostasis of the immune system depends on the proper function of regulatory T cells (T(reg) cells). Compromised suppressive activity of T(reg) cells leads to autoimmune disease and graft rejection and promotes anti-tumor immunity. Here we report a previously unrecognized requirement for the serine-threonine phosphatase PP2A in the function of T(reg) cells. T(reg) cells exhibited high PP2A activity, and T(reg) cell-specific ablation of the PP2A complex resulted in a severe, multi-organ, lymphoproliferative autoimmune disorder. Mass spectrometry revealed that PP2A associated with components of the mTOR metabolic-checkpoint kinase pathway and suppressed the activity of the mTORC1 complex. In the absence of PP2A, T(reg) cells altered their metabolic and cytokine profile and were unable to suppress effector immune responses. Therefore, PP2A is required for the function of T(reg) cells and the prevention of autoimmunity.
authors.affiliation: Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Sokratis A
authors.initials: SA
authors.lastname: Apostolidis
authors.affiliation: Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Noé
authors.initials: N
authors.lastname: Rodríguez-Rodríguez
authors.affiliation: Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Abel
authors.initials: A
authors.lastname: Suárez-Fueyo
authors.affiliation: Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Nikolina
authors.initials: N
authors.lastname: Dioufa
authors.affiliation: Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Esra
authors.initials: E
authors.lastname: Ozcan
authors.affiliation: Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: José C
authors.initials: JC
authors.lastname: Crispín
authors.affiliation: Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Maria G
authors.initials: MG
authors.lastname: Tsokos
authors.affiliation: Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: George C
authors.initials: GC
authors.lastname: Tsokos
mesh_terms: D000818:Animals; D001327:Autoimmune Diseases / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D015551:Autoimmunity / Q000235:genetics / Q000276:immunology; D002478:Cells, Cultured; D002518:Ceramides / Q000276:immunology / Q000378:metabolism; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D015151:Immunoblotting; D019169:Jurkat Cells; D008232:Lymphoproliferative Disorders / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D008297:Male; D000076222:Mechanistic Target of Rapamycin Complex 1; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D046912:Multiprotein Complexes / Q000276:immunology / Q000378:metabolism; D010766:Phosphorylation / Q000276:immunology; D054648:Protein Phosphatase 2 / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology* / Q000378:metabolism; D058570:TOR Serine-Threonine Kinases / Q000276:immunology / Q000378:metabolism
chemical_list: D002518:Ceramides; D046912:Multiprotein Complexes; D000076222:Mechanistic Target of Rapamycin Complex 1; D058570:TOR Serine-Threonine Kinases; D054648:Protein Phosphatase 2