Immunotherapy to treat Hematological Malignancies
Thursday 17 January 2013
Leukemia, lymphoma and myeloma together account for about 500.000 deaths per year worldwide. Often, the only curative treatment for patients suffering these hematological malignancies is allogeneic stem cell transplantation (allo-SCT) from an MHC-matched donor. The curative effect of allo-SCT is mediated by donor T cells that recognize the so called minor histocompatibility antigens. Molecular identification of mHags that are involved therapeutical T cell responses is essential to generate necessary tools, i.e. mHag peptides, mHag genes and mHag-specific T cell receptors (TCRs), for the development of mHag-based immunotherapy strategies for relapsed patients after HLA-matched, mHag-mismatched transplantation. Towards the accomplishment of this important task we developed novel strategies, in which excellent opportunities are available for students who want to enrich their knowledge in T cell immunology. The details of this projects are outlined below as project 1.
Furthermore we are interested in delineating the mechanisms of immune escape of hematological tumors mediated by tumor micro-environment, especially in the setting of multiple myeloma. For this, we use a well established in vitro model and are currently developing an in vivo model, in which we study the T cell mediated lysis of myeloma cells in the presence and absence of cells derived from the tumor microenvironment such as bone marrow stromal cells, endothelial cells and fibroblasts. To bypass the mechanisms of immune escape we furthermore use widely available chemical agents that can block or activate certain pro or anti-apoptotic mechanisms in myeloma cells. The details of this student project and techniques as outlined below in project 2.
For this project mHag-specific cytotoxic T cell clones will be generated from patients who had a strong anti-tumor response after MHC-matched allo-SCT. In order to attack the exciting puzzle of what the exact mHag peptide sequence is (recognized by a mHag specific T cell), we use a recently developed genetic approach (Spaapen et al 2008, J.Exp.Med. 205:863) which is based on genome wide association analysis. Furthermore the student will have the opportunity to study the immunotherapeutic potential of these newly identified mHags in various functional and patient-based assays.
The identified mHags may be in the near future included in clinical trials in which patients with hematological malignancies receive therapeutic vaccinations with dendritic cells loaded with the peptides of these mHags.
Culture of different cell lines and T cells; FACS analysis with antibodies, tetramers; ELISA; genome wide association analyses; biochemical techniques including auantitativePCR, gene cloning and sequencing; retroviral gene transductions; immunological assays ( proliferation, cytokine secretion, cytotoxicityassays).
6 or 9 months
For the in vitro project we use a compartment specific co-culture system in which myeloma cells are co-cultured with the cells of microenvironment (stromal cells, endothelial cells etc) prior to testing their susceptibility for T cell lysis. The intracellular mechanisms of resistance against cytotoxic activity are addressed by studying the accessory cell induced up/down regulation of anti-pro apoptotic proteins in the myeloma cells by western blot. Activation and function of the T cells are analysed by T cell proliferation and cytokine production assays. Ultimate goal is to abrogate the microenvironment induced immune escape by clinically applicable novel compounds, which are tested for their synergistic activity with T cell mediated lysis. For the in vivo experiments we use a humanized MM model in the immunodeficient mice in which human bone marrow microenvironment is effectively mimicked by subcutaneous implantation of scaffolds coated with human bone marrow derived stromal cells. Tumors growing as such or within this in vivo implanted human microenvironment are treated with infusion of human T cell clones to determine the in vivo development of immune resistance and immune suppression.
Culture of different cell lines and T cells, Facs, Elisa, Western Blot, Luciferase based cytotoxicity assays. PCR, SiRNA
6 or 9 months
Dr. T. Mutis, firstname.lastname@example.org, tel 088 75 565 04
Drs. R. Oostvogels, email@example.com, tel 088 75 597 71 (Project 1)
Drs. S. de Haart, firstname.lastname@example.org, tel 088 75 597 71 (Project 2)
Dr. K. Denzer, email@example.com, tel 088 75 5643 68
UMC website - Dept. of clinical chemistry and haematology