Transcriptional complexes formed by NFAT dimers regulate the induction of T cell tolerance.
In T cells, anergy can be induced after T cell receptor engagement in the absence of costimulation. Under these conditions, the expression of a specific set of anergy-associated genes is activated. Several lines of evidence suggest that nuclear factor of activated T cells (NFAT) proteins may regulate the expression of many of those genes; however, the nature of the complexes responsible for the induction of this new program of gene expression is unknown. Here, we show that transcriptional complexes formed by NFAT homodimers are directly responsible for the activation of at least two anergy-inducing genes, Grail and Caspase3. Our data shows that Grail expression is activated by direct binding of NFAT dimers to the Grail promoter at two different sites. Consequently, a mutant NFAT protein with impaired ability to dimerize is not able to induce an unresponsive state in T cells. Our results not only identify a new biological function for NFAT dimers but also reveal the different nature of NFAT-containing complexes that induce anergy versus those that are activated during a productive immune response. These data also establish a basis for the design of immunomodulatory strategies that specifically target each type of complex.
Soto-Nieves
Noemi
N
Department of Pathology, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
Puga
Irene
I
Abe
Brian T
BT
Bandyopadhyay
Sanmay
S
Baine
Ian
I
Rao
Anjana
A
Macian
Fernando
F
D053148:Caspase 3 / Q000235:genetics; D019281:Dimerization; D005786:Gene Expression Regulation; D006801:Humans; D007108:Immune Tolerance; D019169:Jurkat Cells / Q000276:immunology; D009154:Mutation; D050778:NFATC Transcription Factors / Q000235:genetics*; D011401:Promoter Regions, Genetic; D011948:Receptors, Antigen, T-Cell / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*; D014158:Transcription, Genetic; D044767:Ubiquitin-Protein Ligases / Q000235:genetics
D050778:NFATC Transcription Factors; D011948:Receptors, Antigen, T-Cell; C520250:RNF128 protein, human; D044767:Ubiquitin-Protein Ligases; D053148:Caspase 3