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Dugast E, Kiss-Toth E, Docherty L, Danger R, Chesneau M, Pichard V, Judor JP, Pettré S, Conchon S, Soulillou JP, Brouard S, Ashton-Chess J. Identification of tribbles-1 as a novel binding partner of Foxp3 in regulatory T cells. J Biol Chem 2013; 288:10051-10060. [PMID: 23417677 DOI: 10.1074/jbc.m112.448654] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
In a previous study, we identified TRIB1, a serine-threonine kinase-like molecule, as a biomarker of chronic antibody-mediated rejection of human kidneys when measured in peripheral blood mononuclear cells. Here, we focused our analysis on a specific subset of peripheral blood mononuclear cells that play a dominant role in regulating immune responses in health and disease, so-called CD4(+)CD25(+)Foxp3(+) regulatory T cells (Tregs). We isolated both human and murine Treg and non-Treg counterparts and analyzed TRIB1 and Foxp3 mRNA expression by quantitative PCR on the freshly isolated cells or following 24 h of activation. Physical interaction between the human TRIB1 and Foxp3 proteins was analyzed in live cell lines by protein complementation assay using both flow cytometry and microscopy and confirmed in primary freshly isolated human CD4(+)CD25(hi)CD127(-) Tregs by co-immunoprecipitation. Both TRIB1 and Foxp3 were expressed at significantly higher levels in Tregs than in their CD4(+)CD25(-) counterparts (p < 0.001). Moreover, TRIB1 and Foxp3 mRNA levels correlated tightly in Tregs (Spearman r = 1.0; p < 0.001, n = 7), but not in CD4(+)CD25(-) T cells. The protein complementation assay revealed a direct physical interaction between TRIB1 and Foxp3 in live cells. This interaction was impaired upon deletion of the TRIB1 N-terminal but not the C-terminal domain, suggesting an interaction in the nucleus. This direct interaction within the nucleus was confirmed in primary human Tregs by co-immunoprecipitation. These data show a direct relationship between TRIB1 and Foxp3 in terms of their expression and physical interaction and highlight Tribbles-1 as a novel binding partner of Foxp3 in Tregs.
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Affiliation(s)
- Emilie Dugast
- UMR1064, Institut National de la Santé et de la Recherche Médicale, Nantes 44000, France; Faculté de Médecine Université de Nantes, Nantes 44000, France; TcLand Expression, 21 rue de la Noue Bras de Fer, 44200 Nantes, France; Institut de Recherche en Transplantation, Institut de Transplantation Urologie-Néphrologie, Nantes 44000, France
| | - Endre Kiss-Toth
- Department of Cardiovascular Science, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - Louise Docherty
- Department of Cardiovascular Science, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - Richard Danger
- UMR1064, Institut National de la Santé et de la Recherche Médicale, Nantes 44000, France; Faculté de Médecine Université de Nantes, Nantes 44000, France; Institut de Recherche en Transplantation, Institut de Transplantation Urologie-Néphrologie, Nantes 44000, France
| | - Mélanie Chesneau
- UMR1064, Institut National de la Santé et de la Recherche Médicale, Nantes 44000, France; Faculté de Médecine Université de Nantes, Nantes 44000, France; Institut de Recherche en Transplantation, Institut de Transplantation Urologie-Néphrologie, Nantes 44000, France
| | - Virginie Pichard
- UMR1064, Institut National de la Santé et de la Recherche Médicale, Nantes 44000, France; Faculté de Médecine Université de Nantes, Nantes 44000, France; Institut de Recherche en Transplantation, Institut de Transplantation Urologie-Néphrologie, Nantes 44000, France
| | - Jean-Paul Judor
- UMR1064, Institut National de la Santé et de la Recherche Médicale, Nantes 44000, France; Faculté de Médecine Université de Nantes, Nantes 44000, France; Institut de Recherche en Transplantation, Institut de Transplantation Urologie-Néphrologie, Nantes 44000, France
| | - Ségolène Pettré
- UMR1064, Institut National de la Santé et de la Recherche Médicale, Nantes 44000, France; Faculté de Médecine Université de Nantes, Nantes 44000, France; Institut de Recherche en Transplantation, Institut de Transplantation Urologie-Néphrologie, Nantes 44000, France
| | - Sophie Conchon
- UMR1064, Institut National de la Santé et de la Recherche Médicale, Nantes 44000, France; Faculté de Médecine Université de Nantes, Nantes 44000, France; Institut de Recherche en Transplantation, Institut de Transplantation Urologie-Néphrologie, Nantes 44000, France
| | - Jean-Paul Soulillou
- UMR1064, Institut National de la Santé et de la Recherche Médicale, Nantes 44000, France; Institut de Recherche en Transplantation, Institut de Transplantation Urologie-Néphrologie, Nantes 44000, France; Centre Hospitalier Universitaire de Nantes, Nantes 44000, France
| | - Sophie Brouard
- UMR1064, Institut National de la Santé et de la Recherche Médicale, Nantes 44000, France; Institut de Recherche en Transplantation, Institut de Transplantation Urologie-Néphrologie, Nantes 44000, France; Centre Hospitalier Universitaire de Nantes, Nantes 44000, France.
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