Interferon-γ secretion by t(9;22) acute lymphoblastic leukemia-derived dendritic cells

Interferon (IFN)-γ plays an important role in immunity and anti-tumor activity. It is produced by lymphocytes, but was recently shown to be also produced by human myeloid dendritic cells (DCs). We have shown that human mature t(9;22) acute lymphoblastic leukemia-derived (ALL) DCs induced autologous cytotoxic T cell responses and therefore asked whether t(9;22) ALL-DC secreted IFN-γ. IFN-γ varied among three cell line-derived ALL-DCs; median production from seven patient ALL-DCs was 3450pg/ml (range 1450–8675). IFN-γ production was dependent on maturation of ALL-DCs. This is the first demonstration of IFN-γ production by t(9;22) ALL-DCs.