Plasmacytoid dendritic cells deficient in IFNα production promote the amplification of FOXP3(+) regulatory T cells and are associated with poor prognosis in breast cancer patients

The accumulation of plasmacytoid dendritic cells (pDCs) within breast carcinoma lesions is associated with a poor clinical outcome. We demonstrated that the deleterious impact of tumor-associated pDCs (TApDCs) is due to their impaired capacity to produce Type I interferon, which in turn potentiates their ability to sustain the proliferation of immunosuppressive regulatory T cells.