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Available structures
PDB Ortholog search: PDBe RCSB
Aliases FOXP3, AIID, DIETER, IPEX, JM2, PIDX, XPID, forkhead box P3
External IDs MGI: 1891436 HomoloGene: 8516 GeneCards: 50943
RNA expression pattern
PBB GE FOXP3 221333 at tn.png

PBB GE FOXP3 221334 s at tn.png
More reference expression data
Species Human Mouse
RefSeq (mRNA)



RefSeq (protein)



Location (UCSC) Chr X: 49.25 – 49.26 Mb Chr X: 7.58 – 7.6 Mb
PubMed search [1] [2]
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FOXP3 (forkhead box P3), also known as scurfin, is a protein involved in immune system responses.[3] A member of the FOX protein family, FOXP3 appears to function as a master regulator of the regulatory pathway in the development and function of regulatory T cells.[4][5][6] Regulatory T cells generally turn the immune response down. In cancer, an excess of regulatory T cell activity can prevent the immune system from destroying cancer cells. In autoimmune disease, a deficiency of regulatory T cell activity can allow other autoimmune cells to attack the body's own tissues.[7][8]

While the precise control mechanism has not yet been established, FOX proteins belong to the forkhead/winged-helix family of transcriptional regulators and are presumed to exert control via similar DNA binding interactions during transcription. In regulatory T cell model systems, the FOXP3 transcription factor occupies the promoters for genes involved in regulatory T-cell function, and may repress transcription of key genes following stimulation of T cell receptors.[9]


The human FOXP3 genes contain 11 coding exons. Exon-intron boundaries are identical across the coding regions of the mouse and human genes. By genomic sequence analysis, the FOXP3 gene maps to the p arm of the X chromosome (specifically, Xp11.23).[3][10]


Foxp3 is a specific marker of natural T regulatory cells (nTregs, a lineage of T cells) and adaptive/induced T regulatory cells (a/iTregs), also identified by other less specific markers such as CD25 or CD45RB.[4][5][6] In animal studies, Tregs that express Foxp3 are critical in the transfer of immune tolerance, especially self-tolerance.[11]

The induction or administration of Foxp3 positive T cells has, in animal studies, led to marked reductions in (autoimmune) disease severity in models of diabetes, multiple sclerosis, asthma, inflammatory bowel disease, thyroiditis and renal disease.[12] Human trials using regulatory T cells to treat graft-versus-host disease have shown efficacy.[13][14]

Further work has shown that T cells are more plastic in nature than originally thought.[15][16][17] This means that the use of regulatory T cells in therapy may be risky, as the T regulatory cell transferred to the patient may change into T helper 17 (Th17) cells, which are pro-inflammatory rather than regulatory cells.[15] Th17 cells are proinflammatory and are produced under similar environments as a/iTregs.[15] Th17 cells are produced under the influence of TGF-β and IL-6 (or IL-21), whereas a/iTregs are produced under the influence of solely TGF-β, so the difference between a proinflammatory and a pro-regulatory scenario is the presence of a single interleukin. IL-6 or IL-21 is being debated by immunology laboratories as the definitive signaling molecule. Murine studies point to IL-6 whereas human studies have shown IL-21.[citation needed]


In human disease, alterations in numbers of regulatory T cells – and in particular those that express Foxp3 – are found in a number of disease states. For example, patients with tumors have a local relative excess of Foxp3 positive T cells which inhibits the body's ability to suppress the formation of cancerous cells.[18] Conversely, patients with an autoimmune disease such as systemic lupus erythematosus (SLE) have a relative dysfunction of Foxp3 positive cells.[19] The Foxp3 gene is also mutated in the X-linked IPEX syndrome (Immunodysregulation, Polyendocrinopathy, and Enteropathy, X-linked).[20] These mutations were in the forkhead domain of FOXP3, indicating that the mutations may disrupt critical DNA interactions.

In mice, a Foxp3 mutation (a frameshift mutation that result in protein lacking the forkhead domain) is responsible for 'Scurfy', an X-linked recessive mouse mutant that results in lethality in hemizygous males 16 to 25 days after birth.[3] These mice have overproliferation of CD4+ T-lymphocytes, extensive multiorgan infiltration, and elevation of numerous cytokines. This phenotype is similar to those that lack expression of CTLA-4, TGF-β, human disease IPEX, or deletion of the Foxp3 gene in mice ("scurfy mice"). The pathology observed in scurfy mice seems to result from an inability to properly regulate CD4+ T-cell activity. In mice overexpressing the Foxp3 gene, fewer T cells are observed. The remaining T cells have poor proliferative and cytolytic responses and poor interleukin-2 production, although thymic development appears normal. Histologic analysis indicates that peripheral lymphoid organs, particularly lymph nodes, lack the proper number of cells.[citation needed]

Role in cancer[edit]

In addition to FoxP3's role in regulatory T cell differentiation, multiple lines of evidence have indicated that FoxP3 play important roles in cancer development.

Down-regulation of FoxP3 expression has been reported in tumour specimens derived from breast, prostate, and ovarian cancer patients, indicating that FoxP3 is a potential tumour suppressor gene. Expression of FoxP3 was also detected in tumour specimens derived from additional cancer types, including pancreatic, melanoma, liver, bladder, thyroid, cervical cancers. However, in these reports, no corresponding normal tissues was analyzed, therefore it remained unclear whether FoxP3 is a pro- or anti-tumourigeneic molecule in these tumours.[citation needed]

Two lines of functional evidence strongly supported that FoxP3 serves as tumour suppressive transcription factor in cancer development. First, FoxP3 represses expression of HER2, Skp2, SATB1 and MYC oncogenes and induces expression of tumour suppressor genes P21 and LATS2 in breast and prostate cancer cells. Second, over-expression of FoxP3 in melanoma,[21] glioma, breast, prostate and ovarian cancer cell lines induces profound growth inhibitory effects in vitro and in vivo. However, this hypothesis need to be further investigated in future studies.[citation needed]

See also[edit]


  1. ^ "Human PubMed Reference:". 
  2. ^ "Mouse PubMed Reference:". 
  3. ^ a b c Brunkow ME, Jeffery EW, Hjerrild KA, Paeper B, Clark LB, Yasayko SA, Wilkinson JE, Galas D, Ziegler SF, Ramsdell F (Jan 2001). "Disruption of a new forkhead/winged-helix protein, scurfin, results in the fatal lymphoproliferative disorder of the scurfy mouse". Nature Genetics. 27 (1): 68–73. doi:10.1038/83784. PMID 11138001. 
  4. ^ a b Hori S, Nomura T, Sakaguchi S (Feb 2003). "Control of regulatory T cell development by the transcription factor Foxp3". Science. 299 (5609): 1057–61. doi:10.1126/science.1079490. PMID 12522256. 
  5. ^ a b Fontenot JD, Gavin MA, Rudensky AY (Apr 2003). "Foxp3 programs the development and function of CD4+CD25+ regulatory T cells". Nature Immunology. 4 (4): 330–6. doi:10.1038/ni904. PMID 12612578. 
  6. ^ a b Fontenot JD, Rasmussen JP, Williams LM, Dooley JL, Farr AG, Rudensky AY (Mar 2005). "Regulatory T cell lineage specification by the forkhead transcription factor foxp3". Immunity. 22 (3): 329–41. doi:10.1016/j.immuni.2005.01.016. PMID 15780990. 
  7. ^ Josefowicz SZ, Lu LF, Rudensky AY (January 2012). "Regulatory T cells: mechanisms of differentiation and function". Annual Review of Immunology. 30 (January): 531–64. doi:10.1146/annurev.immunol.25.022106.141623. PMID 22224781. 
  8. ^ Zhang L, Zhao Y (Jun 2007). "The regulation of Foxp3 expression in regulatory CD4(+)CD25(+)T cells: multiple pathways on the road". Journal of Cellular Physiology. 211 (3): 590–7. doi:10.1002/jcp.21001. PMID 17311282. 
  9. ^ Marson A, Kretschmer K, Frampton GM, Jacobsen ES, Polansky JK, MacIsaac KD, Levine SS, Fraenkel E, von Boehmer H, Young RA (Feb 2007). "Foxp3 occupancy and regulation of key target genes during T-cell stimulation". Nature. 445 (7130): 931–5. doi:10.1038/nature05478. PMC 3008159free to read. PMID 17237765. 
  10. ^ Bennett CL, Yoshioka R, Kiyosawa H, Barker DF, Fain PR, Shigeoka AO, Chance PF (Feb 2000). "X-Linked syndrome of polyendocrinopathy, immune dysfunction, and diarrhea maps to Xp11.23-Xq13.3". American Journal of Human Genetics. 66 (2): 461–8. doi:10.1086/302761. PMC 1288099free to read. PMID 10677306. 
  11. ^ Ohki H, Martin C, Corbel C, Coltey M, Le Douarin NM (Aug 1987). "Tolerance induced by thymic epithelial grafts in birds". Science. 237 (4818): 1032–5. doi:10.1126/science.3616623. PMID 3616623. 
  12. ^ Suri-Payer E, Fritzsching B (Aug 2006). "Regulatory T cells in experimental autoimmune disease". Springer Seminars in Immunopathology. 28 (1): 3–16. doi:10.1007/s00281-006-0021-8. PMID 16838180. 
  13. ^ Brunstein CG, Miller JS, Cao Q, McKenna DH, Hippen KL, Curtsinger J, Defor T, Levine BL, June CH, Rubinstein P, McGlave PB, Blazar BR, Wagner JE (Jan 2011). "Infusion of ex vivo expanded T regulatory cells in adults transplanted with umbilical cord blood: safety profile and detection kinetics". Blood. 117 (3): 1061–70. doi:10.1182/blood-2010-07-293795. PMC 3035067free to read. PMID 20952687. 
  14. ^ Di Ianni M, Falzetti F, Carotti A, Terenzi A, Castellino F, Bonifacio E, Del Papa B, Zei T, Ostini RI, Cecchini D, Aloisi T, Perruccio K, Ruggeri L, Balucani C, Pierini A, Sportoletti P, Aristei C, Falini B, Reisner Y, Velardi A, Aversa F, Martelli MF (Apr 2011). "Tregs prevent GVHD and promote immune reconstitution in HLA-haploidentical transplantation". Blood. 117 (14): 3921–8. doi:10.1182/blood-2010-10-311894. PMID 21292771. 
  15. ^ a b c Zhou L, Chong MM, Littman DR (May 2009). "Plasticity of CD4+ T cell lineage differentiation". Immunity. 30 (5): 646–55. doi:10.1016/j.immuni.2009.05.001. PMID 19464987. 
  16. ^ Bluestone JA, Mackay CR, O'Shea JJ, Stockinger B (Nov 2009). "The functional plasticity of T cell subsets". Nature Reviews. Immunology. 9 (11): 811–6. doi:10.1038/nri2654. PMC 3075537free to read. PMID 19809471. 
  17. ^ Murphy KM, Stockinger B (Aug 2010). "Effector T cell plasticity: flexibility in the face of changing circumstances". Nature Immunology. 11 (8): 674–80. doi:10.1038/ni.1899. PMC 3249647free to read. PMID 20644573. 
  18. ^ Beyer M, Schultze JL (Aug 2006). "Regulatory T cells in cancer". Blood. 108 (3): 804–11. doi:10.1182/blood-2006-02-002774. PMID 16861339. 
  19. ^ Alvarado-Sánchez B, Hernández-Castro B, Portales-Pérez D, Baranda L, Layseca-Espinosa E, Abud-Mendoza C, Cubillas-Tejeda AC, González-Amaro R (Sep 2006). "Regulatory T cells in patients with systemic lupus erythematosus". Journal of Autoimmunity. 27 (2): 110–8. doi:10.1016/j.jaut.2006.06.005. PMID 16890406. 
  20. ^ Bennett CL, Christie J, Ramsdell F, Brunkow ME, Ferguson PJ, Whitesell L, Kelly TE, Saulsbury FT, Chance PF, Ochs HD (Jan 2001). "The immune dysregulation, polyendocrinopathy, enteropathy, X-linked syndrome (IPEX) is caused by mutations of FOXP3". Nature Genetics. 27 (1): 20–1. doi:10.1038/83713. PMID 11137993. 
  21. ^ Tan B, Anaka M, Deb S, Freyer C, Ebert LM, Chueh AC, Al-Obaidi S, Behren A, Jayachandran A, Cebon J, Chen W, Mariadason JM (Jan 2014). "FOXP3 over-expression inhibits melanoma tumorigenesis via effects on proliferation and apoptosis". Oncotarget. 5 (1): 264–76. doi:10.18632/oncotarget.1600. PMC 3960207free to read. PMID 24406338. 

Further reading[edit]

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