PB1982 AN IN VITRO STUDY OF THE INTERACTIONS BETWEEN THE CELL BASED CANCER VACCINE DCP‐001 AND ANTIGEN PRESENTING CELLS

Abstract

Background:DCP‐001 is a whole cell‐based vaccine derived from the DCOne® human myelomonocytic leukemic cell line. DCOne cells endogenously express known and unknown tumour‐associated antigens. In the DCP‐001 manufacturing process, DCOne cells are differentiated and matured into cells with a mature dendritic cell phenotype. A phase I clinical trial demonstrated that the vaccine is safe and induces local and systemic cellular and humoral immune responses. DCP‐001 is currently studied in an international Phase II trial in AML patients ineligible for HSCT.Aims:To study the role of the interaction of whole cell‐based vaccine DCP‐001 with host immune cells.Methods:DCP‐001 and antigen presenting cell interaction studies were performed using flow cytometry and confocal microscopy. Cytokine/chemokine analyses were performed using luminex technology.Results:The strong immunogenicity of DCP‐001 is demonstrated by the broad range of chemokines and pro‐inflammatory cytokines released upon co‐culture of DCP‐001 with human peripheral blood mononuclear cells. Using different methods, we further demonstrate that antigen presenting cells efficiently process DCP‐001 through phagocytosis.Summary/Conclusion:These in vitro data suggest that in vivo, upon intradermal injection, DCP‐001 induces a strong inflammatory response, and is ingested by both resident as well as attracted host's APC, which subsequently prime tumour‐reactive T cells.