FIG. 10.

Effects of Se intake on CD4⁺ T cell differentiation. Adequate levels of Se intake do not bias T cell differentiation and T helper (Th) 1 versus Th2 differentiation is largely determined by signals provided by the antigen-presenting cell or cytokine milleau. For example, CD4+ T cells activated in a pro-Th1 environment or a pro-Th2 environment can differentiate into either Th1 or Th2 cells. Se supplementation boosts TCR signals and skews differentiation toward a Th1 phenotype. In contrast, Se deficiency leads to low TCR signals and skews differentiation toward lowered activation states with a biase toward a Th2 phenotype.