Dendritic Cell Immunization Induces Nonprotective WT1-specific CTL Responses in Mouse

Can immunotherapy specifically target acute myeloid leukemic stem cells?

Accumulating evidence supports the role of leukemic stem cells (LSCs) in the high relapse rate of acute myeloid leukemia (AML) patients. The clinical relevance of LSCs, which were originally characterized in xenograft models, has recently been confirmed by the finding that stem cell-like gene expression signatures can predict the clinical outcome of AML patients. The targeted elimination of LSCs might hence constitute an efficient therapeutic approach to AML. Here, we review immunotherapeutic strategies that target LSC-associated antigens, including T cell-mediated and monoclonal antibody-based regimens. Attention is given to the issue of antigen specificity because this is relevant to the therapeutic window and determines the superiority of LSC-targeting immunotherapy.

Highlights of the second international conference on "Immunotherapy in Pediatric Oncology"

The Second International Conference on Immunotherapy in Pediatric Oncology was held in Houston, Texas, USA, October 11-12, 2010, to discuss the progress and challenges that have occurred in cutting edge immunotherapeutic strategies currently being developed for pediatric oncology. Major topics included immune targeting of acute lymphoblastic leukemia and pediatric solid tumors, chimeric antigen receptors (CARs) for hematologic malignancies and solid tumors, enhancing graft-versus-leukemia for pediatric cancers, overcoming hurdles of immunotherapy, strategies to active the innate immune system, and moving immunotherapy beyond phase I studies. Significant progress has been made in the last 2 years both in the development of novel immunobiologics such as CARs, and in establishing survival benefits of an anti-GD2 monoclonal antibody in randomized studies. Although there is much excitement going forward, a great deal of laboratory and regulatory challenges lie ahead in improving the efficacy of each of these modalities as well as getting them to patients in a timely and cost-effective fashion. The resulting discussions will hopefully lead to new collaborations and insight for further translational and clinical studies.

Immunotherapy of acute myeloid leukemia: current approaches

Following standard therapy that consists of chemotherapy with or without stem cell transplantation, both relapsed and refractory disease shorten the survival of acute myeloid leukemia (AML) patients. Therefore, additional treatment options are urgently needed, especially to fight residual AML cells. The identification of leukemia-associated antigens and the observation that administration of allogeneic T cells can mediate a graft-versus-leukemia effect paved the way to the development of active and passive immunotherapy strategies, respectively. The aim of these strategies is the eradication of AML cells by the immune system. In this review, an overview is provided of both active and passive immunotherapy strategies that are under investigation or in use for the treatment of AML. For each strategy, a critical view on the state of the art is given and future perspectives are discussed.