Forkhead Box Protein 3
Forkhead Box Protein 3 (FOXP3) is a member of the Forkhead transcription factor family. It is highly expressed in regulatory T (Treg) cells, a subset of CD4+ T cells that play a critical role in suppressing immune responses, especially those mediated by autoreactive T cells.[1] FOXP3 upregulates a number of genes like Cd25 and Ctla4 and represses other genes like IL-2 and Ptpn22.[2] As with many transcription factors, it cooperates with a number of transcription factor partners to regulate gene expression, including NFAT1, which participates in the inducible expression of cytokine genes like IL-2, IL-4, and TNFα in T cells.[3] A number of mutations to FOXP3 are known to result in a severe autoimmune disease known as IPEX (immune dysregulation, polyendocriopthy, enteropathy, X-linked). As FOXP3 is found on the X-chromosome, mutations to FOXP3 typically only display deleterious phenotypic traits in males, resulting in lymphocyte infiltration and wide spread inflammation in inphants.[4] A similar pathology is also found in mice who carry nonsense mutations in the FOXP3 locus. These mutant mice are known as scurfy mice. The targeted elimination of FOXP3+ CD4+ Tregs in adult mice has similar autoimmune dysfunction.[5] Further, ectopic expression of FOXP3 in peripheral CD4+CD25- T cells equips these T cells with the ability to suppress the proliferation and effector functions of autoreactive T cells in vivo.[6] The interaction of FOXP3 with NFAT1 and the FOXP3-NFAT1 target sequences found in IL-2 has been investigated extensively. The Forkhead domain of FOXP3 appears to form a domain swapped dimer with a dimerized rel homology region (RHR) of NFAT1 and two unique oligonucleotides, each containing distinct FOXP sites.[7]
Talk about alignment with FOXP2 and fix the morph.
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