Regulatory T cells in inflammatory bowel diseases and colorectal cancer

Figure 1 Phenotypic plasticity of T cells in inflammatory bowel disease. The mucosal concentration of transforming growth factor (TGF)-β influences the interleukin (IL)-23 receptor expression of antigen activated CD4+ T cells, which results imbalance in forkhead box P3 (Foxp3) and retinoic acid-related orphan receptor (RORγt) transcription factor activity. The Foxp3 dependent inhibition or stimulation of RORγt may regulate helper T cell (Th) 17 or Foxp3+ regulatory T cell (T_reg) differentiation. The inflammatory cytokine/chemokine milieu may also influence the phenotypic changes of T cells.