title: The mTOR kinase determines effector versus memory CD8+ T cell fate by regulating the expression of transcription factors T-bet and Eomesodermin.
abstract: The mechanisms underpinning integration of instructions that program naive CD8+ T cells for effector and/or memory differentiation are not well understood. Herein, we demonstrate that interleukin-12 (IL-12) enhanced and sustained antigen and costimulatory molecule (B7.1)-induced mTOR kinase activity in naive CD8+ (OT-I) T cells via phosphoinositide 3-kinase and STAT4 transcription factor pathways. Blocking mTOR activity by rapamycin reversed IL-12-induced effector functions because of loss of persistent expression of the transcription factor T-bet. Rapamycin treatment of IL-12-conditioned OT-I cells promoted persistent Eomesodermin expression and produced memory cell precursors that demonstrated enhanced sustenance and antigen-recall responses upon adoptive transfer. The memory cell precursors showed greater tumor efficacy than IL-12-conditioned effector OT-I cells. These results identify mTOR as the central regulator of transcriptional programs that determine effector and/or memory cell fates in CD8+ T cells. Targeting mTOR activity offers new opportunities to regulate CD8+ T cell-mediated immunity.
authors.affiliation: Department of Immunology, Roswell Park Cancer Institute, Buffalo, NY 14263, USA.
authors.forename: Rajesh R
authors.initials: RR
authors.lastname: Rao
authors.forename: Qingsheng
authors.initials: Q
authors.lastname: Li
authors.forename: Kunle
authors.initials: K
authors.lastname: Odunsi
authors.forename: Protul A
authors.initials: PA
authors.lastname: Shrikant
mesh_terms: D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D002454:Cell Differentiation / Q000276:immunology*; D007156:Immunologic Memory / Q000276:immunology; D047908:Intracellular Signaling Peptides and Proteins / Q000276:immunology* / Q000378:metabolism; D008213:Lymphocyte Activation / Q000276:immunology; D051379:Mice; D008822:Mice, Transgenic; D017346:Protein Serine-Threonine Kinases / Q000276:immunology* / Q000378:metabolism; D015398:Signal Transduction / Q000276:immunology; D020825:T-Box Domain Proteins / Q000096:biosynthesis / Q000276:immunology*; D016176:T-Lymphocyte Subsets / Q000276:immunology* / Q000378:metabolism; D058570:TOR Serine-Threonine Kinases; D014161:Transduction, Genetic; D000098815:T-bet Transcription Factor
chemical_list: C491198:Eomes protein, mouse; D047908:Intracellular Signaling Peptides and Proteins; D020825:T-Box Domain Proteins; D000098815:T-bet Transcription Factor; C546843:mTOR protein, mouse; D017346:Protein Serine-Threonine Kinases; D058570:TOR Serine-Threonine Kinases