Transcription factor Foxo3 controls the magnitude of T cell immune responses by modulating the function of dendritic cells.
Foxo transcription factors regulate cell cycle progression, cell survival and DNA-repair pathways. Here we demonstrate that deficiency in Foxo3 resulted in greater expansion of T cell populations after viral infection. This exaggerated expansion was not T cell intrinsic. Instead, it was caused by the enhanced capacity of Foxo3-deficient dendritic cells to sustain T cell viability by producing more interleukin 6. Stimulation of dendritic cells mediated by the coinhibitory molecule CTLA-4 induced nuclear localization of Foxo3, which in turn inhibited the production of interleukin 6 and tumor necrosis factor. Thus, Foxo3 acts to constrain the production of key inflammatory cytokines by dendritic cells and to control T cell survival.
Molecular Biology Section, Division of Biological Sciences, Department of Cellular and Molecular Medicine, University of California, San Diego, San Diego, California, USA.
Anne S
AS
Dejean
Daniel R
DR
Beisner
Irene L
IL
Ch'en
Yann M
YM
Kerdiles
Anna
A
Babour
Karen C
KC
Arden
Diego H
DH
Castrillon
Ronald A
RA
DePinho
Stephen M
SM
Hedrick
D000818:Animals; D017951:Antigen Presentation / Q000276:immunology; D015703:Antigens, CD / Q000276:immunology / Q000378:metabolism; D001117:Arenaviridae Infections / Q000276:immunology; D015153:Blotting, Western; D060908:CTLA-4 Antigen; D003713:Dendritic Cells / Q000276:immunology* / Q000378:metabolism; D005434:Flow Cytometry; D000071316:Forkhead Box Protein O3; D051858:Forkhead Transcription Factors / Q000276:immunology* / Q000378:metabolism; D015850:Interleukin-6 / Q000276:immunology / Q000378:metabolism; D008213:Lymphocyte Activation / Q000276:immunology*; D008217:Lymphocytic choriomeningitis virus / Q000276:immunology; D051379:Mice; D020297:Mice, Congenic; D008822:Mice, Transgenic; D021381:Protein Transport / Q000276:immunology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology / Q000378:metabolism
D015703:Antigens, CD; D060908:CTLA-4 Antigen; C556707:Ctla4 protein, mouse; D000071316:Forkhead Box Protein O3; D051858:Forkhead Transcription Factors; C474033:FoxO3 protein, mouse; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha