INFα-2b inhibitory effects on CD4+ CD25 + FOXP3+ regulatory T cells in the tumor microenvironment of C57BL/6 J mice with melanoma xenografts

Regulatory T cells (Tregs), particularly the CD4+ CD25+ Foxp3+ Tregs, down regulate immunity and promote tumor cell growth by directly suppressing CD8+ and CD4+ T cells. Alternatively they can promote tumor growth by generating interleukin-10 (IL-10) and transforming growth factor β (TGFβ) in situ, which help tumor cells to evade the immune system.