Immune Modulation in Hematologic Malignancies

The therapeutic potential of the immune system in the context of hematologic malignancies has long been appreciated particularly due to the curative impact of allogeneic hematopoietic stem cell transplantation (SCT). The role of immune system in shaping the biology and evolution of these tumors is now well recognized. While the contribution of the immune system in anti-tumor effects of certain therapies such as immune-modulatory drugs and monoclonal antibodies active in hematologic malignancies is quite evident, the immune system has also been implicated in anti-tumor effects of other targeted therapies. The horizon of immune-based therapies in hematologic malignancies is rapidly expanding with promising results from immune-modulatory drugs, immune-checkpoint blockade, and adoptive cellular therapies, including genetically-modified T cells. Hematologic malignancies present distinct issues (relative to solid tumors) for the application of immune therapies due to differences in cell of origin/developmental niche of tumor cells, and patterns of involvement such as common systemic involvement of secondary lymphoid tissues. This article discusses the rapidly changing landscape of immune modulation in hematologic malignancies and emphasizes areas wherein hematologic malignancies present distinct opportunities for immunologic approaches to prevent or treat cancer.