Tumor derived TGF-beta induces the conversion of tumor infiltrating CD4 T cells into FoxP3+ regulatory T cells

CD4+CD25+ regulatory T cells play an important role in the tolerance of the immune system towards tumors. These regulatory T cells specifically express the transcription factor FoxP3 and are believed to be generated in the thymus. However recent data have demonstrated that peripheral T cells can convert into regulatory T cells. Here we demonstrate the TGF-beta dependent induction of FoxP3+ regulatory T cells in the colon with a potential role in the pathogenesis of colon cancer. Accordingly colon tumors were induced by a single dose of the mutagenic agent azoxymethane followed by three weekly periods of DSS in d…