Grant: 5447-16 | Career Development Program (CDP):
Location:Board of Trustees of the Leland Stanford Junior University, San Francisco, California 94144-4253
Project Title: SINGLE CELL RNA IMAGE SEQUENCING FOR SPATIO-TEMPORAL ANALYSIS OF T-CELL DEVELOPMENT FROM STEM CELLSProject Summary:
Grant: R6503-16 | Translational Research Program (TRP):
Location:Regents of the University of Michigan, Pittsburgh, Pennsylvania 15251-2131
Project Title: Peripheral T-cell Lymphoma, Not Otherwise Specified: The Cell Of Origin As A Predictive Biomarker And Therapeutic Target.Project Summary:
T-cell cancers, collectively referred to as T-cell lymphomas (TCLs), are relatively rare, difficult to classify, and poorly understood. Most TCLs are clinically aggressive and resistant to standard chemotherapy regimens. Therefore, these lymphomas are rarely curable with existing therapies. We believe that the biology of normal (noncancerous) human T cells can provide clues about TCL classification that may lead to the development of improved treatment strategies. For example, different subsets of normal T cells are tightly controlled by a group of regulatory proteins. One of these proteins, called GATA-3, regulates the growth and survival of a particular T-cell subset. We speculated that expression of GATA-3 and other related proteins might determine important aspects of TCL biology and aid in TCL classification. We found that the majority of patients with the most common TCL express either GATA-3 or an alternative regulatory protein, T-bet. These patients were previously thought to have the same TCL. However, our findings demonstrate that this TCL comprises two clinically and molecularly distinct subsets: one characterized by GATA-3 expression and the other by T-bet expression. These findings have significant implications for the classification of this TCL and for its treatment. For example, one of these TCL subsets may respond better than the other to standard chemotherapeutic agents. We will conduct a multicenter clinical trial to address this possibility. Patients with relapsed or refractory TCL will be classified as having either “GATA-3” or “T-bet” TCL prior to treatment with one of four standard chemotherapy agents (selected by their physician), and the response to treatment will be subsequently evaluated. We anticipate that the results of this study will help physicians select the “right therapy” for the “right patient”. Part of this effort will require development of reliable, accurate, and clinically accessible assays to identify these TCL subsets. We will examine two complementary assays in a large cohort of well-characterized TCL patients. While optimization of currently available therapies is important, an equally important goal is the development of improved therapeutic strategies. For the second proposed study, we will test a new therapeutic strategy based on our work demonstrating that GATA-3 confers resistance to chemotherapy. Since GATA-3 expression is controlled by a cell surface protein called the T-cell receptor (TCR), inhibition of TCR signals by the oral chemotherapeutic agent Ixazomib should inhibit GATA-3 expression in TCL. This novel therapeutic strategy will be examined in a single center, phase II study. We hope that the knowledge gained from this body of work will ultimately improve outcomes for patients afflicted with these aggressive lymphomas.
Grant: 6488-16 | Translational Research Program (TRP):
Location:Albert Einstein College of Medicine, Inc., Bronx, New York 10461
Project Title: STAT3 Inhibition As A Therapeutic Strategy Against MDS And AML Stem CellsProject Summary:
Myelodysplastic syndromes and acute myeloid leukemia are blood cancers that are increasing in incidence and can result from exposure to harmful chemicals and ionizing radiation. These diseases are caused by genetic changes in the blood stem cells that lead to a disruption of their functionality. Blood stem cells are capable of differentiating in all different types of blood cells and rely on certain networks of genes that have to be switched on or off in a coordinated manner. We have shown that stem cells in MDS and AML patients have genetic alterations. We have also shown that these abnormal stem cells are not killed by drugs such as azacytidine and are a cause of disease relapse. Thus, identification of targets against these abnormal stem cells is important in the development of future curative therapeutic strategies. In this proposal we aim to target MDS stem cells with a drugs against the protein STAT3. We have shown that abnormal stem cells from MDS and AML patients have higher levels of STAT3 and that patients with higher STAT3 levels have a shorter lifespan. Our work has shown that inhibiting this protein can lead to death of MDS/AML stem cells and potentially prevent disease relapses. We propose to test a novel protein based drug called STAT3-ISIS-Rx in human samples and animal models of MDS and AML. This agent is also a selective inhibitor of the STAT3 protein and is being tested in clinical trials in lymphoma We also propose to test an approved drug, Pyrimethamine, that is being used in another leukemia (CLL) based on its ability to inhibit the STAT3 protein. We will test whether inhibition of STAT3 by these drugs can inhibit genetically abnormal MDS stem cells in patients. Our studies will lead to its development of these agents in future clinical trials in MDS and AML patients.
Grant: R6501-16 | Translational Research Program (TRP):
Location:Mayo Clinic Rochester, Minneapolis, Minnesota 55486-0334
Project Title: Overcoming T-cell Exhaustion In Follicular B-cell LymphomaProject Summary:
Immune cells within the tumor play a critical role in follicular non-Hodgkin lymphoma (NHL). Although lymphoma B-cells predominate, other cells are commonly present in malignant lymph nodes. These cells include T lymphocytes that appear to target lymphoma B-cells, and while increased numbers of intratumoral T-cells are associated with an improved outcome, intratumoral T-cells seem unable to eradicate the malignant cells.
In work done during the initial funding period, we have shown that intratumoral T-cells in follicular lymphoma are functionally exhausted due to chronic cytokine stimulation. Specifically, we have found that immunostimulatory proteins including interleukin-12 (IL-12), transforming growth factor beta (TGF-β) and monokine induced by gamma interferon (MIG/CXCL9) cause T-cell exhaustion. Exhausted T-cells are characterized by expression of TIM-3 and PD-1 on the cell surface. Exhausted cells are unable to grow, produce cytokines or respond to activation, and signaling through PD-1 perpetuates the exhausted T-cell phenotype. Increased numbers of intratumoral TIM-3+PD-1+ T-cells are associated with a poor prognosis and an increased likelihood of transformation to a more aggressive lymphoma.
We therefore hypothesize that blocking PD-1 signaling will reverse T-cell exhaustion and result in clinical benefit for lymphoma patients. Initial clinical trials have reported responses in low-grade lymphoma patients treated with anti-PD-1 antibodies, but not all patients treated benefited from this therapy. In this grant renewal, we propose to test the safety and efficacy of an anti-PD-1 antibody, pembrolizumab, in patients with relapsed low-grade lymphoma and to identify the immune cell composition that is associated with clinical responses. We will then determine whether reversal of T-cell exhaustion is the dominant mechanism responsible for clinical benefit.
Successful completion of the aims of this proposal will result not only in confirmation of a novel therapy to improve tumor immunity in patients with follicular lymphoma, but also in the identification of an immune signature that identifies patients most likely to benefit from this treatment approach.
Grant: 1331-16 | Career Development Program (CDP):
Location:Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania 19104-6205
Project Title: Towards A Quantitative Understanding Of Mixed-lineage Leukemia Family Substrate TargetsProject Summary:
Mixed-lineage leukemia (MLL) gene mutations are frequent in both pediatric and adult leukemias. While studies have helped define the genetic determinants driving these leukemias, these aggressive blood cancers still have the worse prognosis despite improved treatment options. Therefore, the development of novel drug therapies is highly needed. However, before new therapeutic strategies can be designed, a thorough understanding of the molecular level consequences of MLL gene targets must be achieved. The MLL gene encodes for an enzyme that adds a chemical modification (methyl) to the side chains of lysine amino acids, with its most well-known target being histone H3, a protein that is involved in structurally making our chromosomes and controlling gene expression. Nevertheless, as there are several related MLL gene family members and their enzymatic activities are significantly altered in the disease state, determining how these enzymes impact cellular targets will greatly help in understanding the molecular pathology of this disease. Towards this end, my lab has been developing novel technology that we propose to use to identify and study downstream targets of MLLs that could be critical for leukemia induction and propagation. We believe that our approaches will help improve the fundamental understanding of the molecular level causes of MLL triggered leukemia and could lay down the foundation for new diagnostics or development of innovative therapeutic intervention.
Grant: 0863-15 | Quest for CURES (QFC):
Location:University of Southern California, Los Angeles, California 90074-2095
Project Title: Characterizing Hematopoietic Stem And Progenitor Cell Senescence With Aging In HumansProject Summary:
Cells in our body including stem or mother cells accumulate damage in their DNA as they continue to divide with age. When a cell has accumulated excess DNA damage it is recognized by the cell machinery and makes the cell undergo permanent arrest from further multiplication. This is called senescence and is the principle mechanism of how we age. However, this helps keep damaged cells from spawning tumors. Loss of this process in the cell can lead to cancer. Several genes regulate senescence. TP53 is one such gene and is the most common gene mutated in cancer. TP53 mutation is common in blood cancers in the elderly. We have shown that that this occurs commonly in leukemia that arises from patients treated with chemotherapy and is the earliest event in leukemia development. Chemotherapy, which poisons fast-dividing cancer cells, also induces senescence in many normal cells. If these damaged cells escape from senescence, they can further mutate, and turn into cancer. We propose that the escape from senescence in blood stem cells is a key mechanism of how blood cancers arise in the elderly. The mechanism by which different compartments of blood cells undergo senescence in humans is poorly studied. We propose a comprehensive and systematic study of how the genetic material changes with aging in various blood compartments. We believe this could lead to a better understanding of both normal and cancerous changes that occur with aging, providing useful markers of both types.
Grant: 1330-16 | Career Development Program (CDP):
Location:Boston Children's Hospital, Boston, Massachusetts 02241-4413
Project Title: Clonal Analysis Of Hematopoietic Development And MalignancyProject Summary:
The technology developed by the investigator allows the tracking of thousands of single cell simultaneously. With this technology, we propose to understand how blood-forming stem cells function in an organism at the single cell level. Additionally, the same technology will be applied to study the development and evolution of single cells in a leukemia model in mice. Knowledge gained form these studies will be critical for understanding the cells-of-origin of hematopoietic disease, the clonal organization of tumor cells and their mechanisms of therapy resistance.
Grant: 6490-16 | Translational Research Program (TRP):
Location:Centre Hospitalier Universitaire Vaudois, Lausanne, Vaud CH-1011
Project Title: Genetically Engineered Virus-specific T Cells To Prevent And Treat Relapse And Infection After Allogeneic Hematopoietic Stem Cell TransplantationProject Summary:
Transplantation of blood-forming stem cells from a healthy person to a patient with blood cancer (e.g. leukemia) can cure these diseases. However, the patient’s immune system is significantly weakened by this procedure, which frequently leads to serious or fatal viral infections, and unfortunately, the blood cancer can also come back. We propose a single approach that can overcome both problems. T cells are a part of the immune system with the capacity to fight against viral infections and to attack blood cancer cells in the patient’s body. Our group has previously shown that T cells from healthy people manipulated in our laboratories can be used to treat infections and blood cancer in patients. We take the T cells from the blood of the original stem cell donor, grow them in the laboratory and train the cells so that they recognize a few specific viruses as well as the blood cancer cells. We then give the T cells to the patient, where they can protect against viral infections and attack cancer cells, leading to cancer elimination from the patient’s body and preventing it from coming back. For the T cells to completely destroy the cancer, however, they need to be able to survive in the body for a long time. We will test new ways of ensuring these cells live longer in the patients by making them recognize viruses and cancer cells at the same time, and “trick” them into thinking the cancer cell is a type of virus infection. We will also engineer the cells to enable faster growth in the presence of a chemical that we know is produced in the same locations that the cancers grow. We think that this three-fold approach will protect patients from viral infections, improve the persistence and anti-cancer actions of the T cells and eradicate the cancer. We will test this new treatment strategy in the laboratory and if the results are promising, in later studies we will test it in patients after a stem cell transplant.
Grant: 6480-16 | Translational Research Program (TRP):
Location:New York University School of Medicine, Boston, Massachusetts 02241-415026
Project Title: Therapeutic Targeting Of The Bone Marrow ALL NicheProject Summary:
Although much is known about the cell-intrinsic factors that support leukemia, little is understood about the role of the leukemia microenvironment (niche) in distinct tissues, including the bone marrow, one of the initial sites of acute leukemia initiation. We were able to show that in pediatric T cell acute leukemia (T-ALL), cancer cells are in direct, stable contact with bone marrow niche cells that express the chemokine CXCL12. We have also shown that CXCL12 inhibition severely impeded tumor growth, leading to prolonged disease remission, suggesting that targeting the chemokine: receptor interaction could be a future therapeutic. Here we present data that extensively support this hypothesis, visualizing for the first time leukemia:niche interactions in live animals and targeting niche functions. In this application we target the leukemia microenvironment using compounds (i.e. CXCL12 inhibitors) currently on clinical trials and we discover novel factors expressed by the T-ALL niche that can be targeted pharmacologically. This is one of the first studies that proposes the targeting of tumor microenvironment in acute leukemia.
Grant: 6481-16 | Translational Research Program (TRP):
Location:Fondazione Centro San Raffaele , Milano, Lombardia 20132
Project Title: Targeting AML By Lipid Antigen-specific T Cells Restricted For CD1Project Summary:
The immune system controls cancer progression by detecting antigenic differences generated during the oncogenic process. Tumor-specific T lymphocytes and tumor associated antigens are exploited in cancer immunotherapy, a treatment that holds great promise. The T lymphocytes that are currently exploited in cancer immunotherapy recognize cancer protein fragments (peptides) bound in antigen-presenting molecules of the Major Histocompatiblity Complex (MHC). MHC molecules are extremely variable (polymorphic) among individuals and such variability is at the basis of immunological rejection in transplantation. In hematopoietic stem cell transplantation (HSCT) donor T lymphocytes recognize MHC-incompatible (allogeneic) cells of the patient (alloreactive reaction). Acute myeloid leukemia (AML) comprises a heterogeneous group of hematological disorders characterized by the growth of abnormal cells derived from hematopoietic precursors. High-risk AML is currently treated with conditioning chemotherapy and allogeneic hematopoietic stem cell transplantation (HSCT). A major cause of treatment failure is the post-transplant re-growth of residual leukemia blasts that survive the conditioning regimen. The transfer alloreactive T lymphocytes of HSCT donors into patients can induce a beneficial graft versus leukemia (GVL) reaction capable of maintaining leukemia control (remission). The allogeneic T cells, however, recognize also non-hematopoietic tissues of the patients, resulting in a life threatening graft versus host disease (GVHD). A promising therapeutic strategy is the selective targeting of allogeneic T cells against malignant hematopoietic cells, while maintaining hematopoietic capacity among grafted cells and preserving organ functions in recipient patients. The recent discovery of T cells that recognize lipid antigens presented by CD1 molecules may provide a new perspective for this strategy: i The expression of CD1 antigen-presenting molecules is confined to mature leukocytes, thus avoiding potential harmful recognition of non-hematopoietic tissues; 2. Being CD1 molecules non-polymorphic, they can be recognized by any CD1-restricted T cell irrespective of the donor. We have recently shown that primary AML blasts express CD1 molecules and a new lipid antigen, called methyl-lyso phosphatidic acid (mLPA), which is specifically recognized by a large group of CD1-restricted T lymphocytes. In light of these considerations, our proposal aims at testing the hypothesis that CD1 autoreactive T cell responses might be harnessed to attack CD1 AML in adoptive immunotherapy, resulting in GVL without GVHD. We will assess efficacy and safety of adoptive cell therapy with CD1 autoreactive T cells for AML in different human and mouse leukemia model that we recently implemented. This study may provide a novel conceptual framework for a safer and more efficacious cure of AML based on the effector properties of T cells specific for self-lipids.