The evolving role of monoclonal antibodies and dendritic cell therapy in hematologic malignancies

Novel immunotherapies

Multiple myeloma is still a fatal disease. Despite advances in high-dose chemotherapy and stem-cell transplantation and the development of novel therapeutics, relapse of the underlying disease remains the primary cause of treatment failure. Strategies for posttransplantation immunomodulation are desirable for eradication of remaining tumor cells. To this end, immunotherapy aimed at inducing myeloma-specific immunity in patients has been explored. Idiotype protein, secreted by myeloma cells, has been the primary target for immunotherapy as it is the best defined tumor-specific antigen. This chapter focuses on novel immunotherapies that are being developed to treat patients with myeloma. I will discuss potential myeloma antigens, antigen-specific T cells, and their function on myeloma tumor cells, and T-cell-based and antibody-based immunotherapies for myeloma. Furthermore, clinical studies of T-cell-based immunotherapy in the form of vaccination, allogeneic stem-cell transplantation and donor lymphocyte infusions, with or without donor vaccination using patient-derived idiotype, and future application of donor-derived or patient-derived, antigen-specific T-cell infusion in this disease are also discussed. Based on the specificity of the immune effector molecules and cells, immunotherapies with specific T cells or therapeutic antibodies may represent novel strategies for the treatment of multiple myeloma in the near future.

Current advances, problems and prospects for vaccine-based immunotherapy in follicular non-Hodgkin's lymphoma

Despite advances in chemotherapy, radiotherapy and combined modality treatment, a significant proportion of non-Hodgkin's lymphomas remain incurable. The disease usually responds well to chemotherapy or radiation, but relapses are observed within months to a few years, with frequent failure of subsequent therapies. High-dose chemotherapy with or without radiation and autologous or allogeneic hematopoietic stem cell transplantation provide higher cure rates and longer remissions in certain patients with aggressive lymphomas. However, the higher treatment-related morbidity and mortality of high-dose chemotherapy has driven a search for new and more tumor-specific treatment modalities, such as immunotherapy. Tumor antigens expressed by B-cell lymphomas, such as the "idiotype antigen", are seen as unique and specific target molecules for direct lymphoma immunotherapy. This review will delineate advances, problems and prospects for approaches to anti-B cell lymphoma immunotherapy where pre-clinical studies and proof of principle have been directly translated to patient care.

Targeting beta2-microglobulin for induction of tumor apoptosis in human hematological malignancies

We discovered that monoclonal antibodies (mAbs) specific to human beta(2)-microglobulin (beta(2)M) induce apoptosis in vitro and were therapeutic in mouse models of myeloma and other hematological tumor cells. Cell death occurred rapidly, without the need for exogenous immunological effector mechanisms. The mAbs induced cell death via recruiting MHC class I molecules to lipid rafts and activating Lyn and PLCgamma2, leading to activated JNK and inhibited PI3K/Akt and ERK, compromised mitochondrial integrity, and caspase-9-dependent cascade activation. Although the expression of beta(2)M on normal hematopoietic cells is a potential safety concern, the mAbs were selective to tumor-transformed cells and did not induce apoptosis of normal cells. Therefore, such mAbs offer the potential for a therapeutic approach to hematological malignancies.