Plasmacytoid pre-dendritic cells (pDC): from molecular pathways to function and disease association.

Plasmacytoid pre-dendritic cells (pDC) are a specialized DC population with a great potential to produce large amounts of type I interferon (IFN). pDC are involved in the initiation of antiviral immune responses through their interaction with innate and adaptive immune cell populations. In a context-dependent manner, pDC activation can induce their differentiation into mature DC able to induce both T cell activation or tolerance. In this review, we described pDC functions during immune responses and their implication in the clearance or pathogenicity of human diseases during infection, autoimmunity, allergy and cancer. We discuss recent advances in the field of pDC biology and their implication for future studies.

The DNA Repair Inhibitor Dbait Is Specific for Malignant Hematologic Cells in Blood.

Hematologic malignancies are rare cancers that develop refractory disease upon patient relapse, resulting in decreased life expectancy and quality of life. DNA repair inhibitors are a promising strategy to treat cancer but are limited by their hematologic toxicity in combination with conventional chemotherapies. Dbait are large molecules targeting the signaling of DNA damage and inhibiting all the double-strand DNA break pathways. Dbait have been shown to sensitize resistant solid tumors to radiotherapy and platinum salts. Here, we analyze the efficacy and lack of toxicity of AsiDNA, a cholesterol form of Dbait, in hematologic malignancies. We show that AsiDNA enters cells via LDL receptors and activates its molecular target, the DNA dependent protein kinase (DNA-PKcs) in 10 lymphoma and leukemia cell lines (Jurkat-E6.1, MT-4, MOLT-4, 174xCEM.T2, Sup-T1, HuT-78, Raji, IM-9, THP-1, and U-937) and in normal primary human PBMCs, resting or activated T cells, and CD34+ progenitors. The treatment with AsiDNA induced necrotic and mitotic cell death in most cancer cell lines and had no effect on blood or bone marrow cells, including immune activation, proliferation, or differentiation. Sensitivity to AsiDNA was independent of p53 status. Survival to combined treatment with conventional therapies (etoposide, cyclophosphamides, vincristine, or radiotherapy) was analyzed by isobolograms and combination index. AsiDNA synergized with all treatments, except vincristine, without increasing their toxicity to normal blood cells. AsiDNA is a novel, potent, and wide-range drug with the potential to specifically increase DNA-damaging treatment toxicity in tumor without adding toxicity in normal hematologic cells or inducing immune dysregulation. Mol Cancer Ther; 16(12); 2817-27. ©2017 AACR.