FoxP3 antibody - HS-491 017

The transcription factor FoxP3 belongs to the family of forkhead transcription factors and controls the differentiation and function of regulatory T-cells (Tregs) (1). Tregs develop either in the thymus (tTreg), where they represent only ~2-3% of developing CD4+ thymocytes, or in the periphery by conversion of conventional CD4+ T cells into peripherally induced Treg (pTreg) cells (2). Expression of FoxP3 is induced by strong and persistent T cell receptor (TCR) signaling. FoxP3 binds DNA as homodimer or heterodimer with Foxp1 and interacts with other downstream transcription factors of TCR signaling, e.g., AP-1 transcription factors, NF-κB or Runx1 (1). Increasing evidence suggests that FoxP3 is expressed not only in Tregs, but also in a variety of tumor cells. However, tumor-FoxP3 has an inconsistent functional role and acts either as a tumor-suppressor or as a tumor-promoting factor (3). Mutations in FoxP3 lead to the severe autoimmune phenomena observed in patients with immune dysregulation, polyendocrinopathy, enteropathy, X-linked syndrome (IPEX) and in scurfy mice (4).