This book systematically reviews the most important findings on cancer immune checkpoints, sharing essential insights into this rapidly evolving yet largely unexplored research topic. The past decade has seen major advances in cancer immune checkpoint therapy, which has demonstrated impressive clinical benefits. The family of checkpoints for mediating cancer immune evasion now includes CTLA-4, PD-1/PD-L1, CD27/CD70, FGL-1/LAG-3, Siglec-15, VISTA (PD-1L)/VSIG3, CD47/SIRPA, APOE/LILRB4, TIGIT, and many others. Despite these strides, most patients do not show lasting remission, and some cancers have been completely resistant to the therapy. The potentially lethal adverse effects of checkpoint blockade represent another major challenge, the mechanisms of which remain poorly understood. Compared to the cancer signaling pathways, such as p53 and Ras, mechanistic studies on immune checkpoint pathways are still in their infancy. To improve the responses to checkpoint blockade therapy and limit the adverse effects, it is essential to understand the molecular regulation of checkpoint molecules in both malignant and healthy cells/tissues. This book begins with an introduction to immune checkpoint therapy and its challenges, and subsequently describes the regulation of checkpoints at different levels. In closing, it discusses recent therapeutic developments based on mechanistic findings, and outlines goals for future translational studies. The book offers a valuable resource for researchers in the cancer immunotherapy field, helping to form a roadmap for checkpoint regulation and develop safer and more effective immunotherapies.

For the faultless function of the immune system, tight regulation of immune cell activation, immuno-suppression and the strength and efficiency of the immune response is essential. Immune checkpoint (ICP) molecules can amplify or dampen signals that lead to the modulation of specific immune activities. Under physiological conditions, immune checkpoints are essential to prevent autoimmune manifestations and to preserve self-tolerance. They help modulate immune responses by either promoting or inhibiting T-cell activation. However, in the context of cancer, malignant cells can dysregulate the expression of immune checkpoint proteins on immune cells in order to suppress anti-tumor immune responses and to gain immune resistance. Moreover, tumor cells themselves can also express some checkpoints proteins, thereby enabling these cells to externally orchestrate immune regulatory mechanisms. Several recent studies have confirmed that the expression of immune checkpoints could be an important prognostic parameter for cancer development and for patient outcome. Therefore, cancer immunotherapy based on the modulation of immune checkpoint molecules alone, or in combination with conventional tumor therapy (chemo- or/and radiotherapy), is now in focus as a means of developing new therapeutic strategies for different types of cancer. The two well-known molecules - CTLA4 and PD-1 - serve as important examples of such checkpoint proteins of important therapeutic potential. Thus far, inhibitors of CTLA4 and PD-1 have been approved to treat only a limited number of malignancies (e.g. malignant Melanoma, Non-Small Cell Lung Cancer). Many others are currently under investigation and the list of immune checkpoint molecules for potential therapeutic targeting is still growing. However, the clinical response to inhibitors of checkpoint molecules is not sufficient in all cases. Therefore, further studies are needed to improve our knowledge of such immunomodulatory proteins and their associated signaling pathways. Several key signaling pathways which are involved in the regulation of expression of checkpoint molecules in immune cells and in cancer cells have already been identified including MAPK, PI3K, NF-kB, JAKs and STATs. These (and future discovered) signaling pathways could give rise to the development of new strategies for modulating the expression of ICPs and thereby, improving anti-cancer immune responses. The main aim of the Research Topic is to collect novel findings from scientists involved in basic research on immune checkpoints as well as in translational studies investigating the use of checkpoint inhibtors in immunotherapy in experimental settings. We welcome the submission of Review, Mini-Review and Original Research articles that cover the following topics: 1. Molecular mechanisms underlying regulation of ICP expression in immune and/or cancer cells. 2. Characterization of signaling pathways downstream ICP molecules. 3. Cellular responses to ICP blockade. 4. Identification of new compounds interfering with ICP expression and/or signaling. 5. ICP-mediated interactions between cancer cells and immune cells. 6. Functional links between ICP and cytokines/chemokines. 7. Molecular mechanisms of ICP inhibition in the context of experimental cancer immunotherapy.

This volume reviews the current state of research on immune checkpoints and offers novel concepts. It discusses the two most important immune checkpoints: T lymphocyte-associated antigen-4 (CTLA-4) and programmed cell death-1 (PD-1). It shows that antagonistic antibodies against these two molecules are highly effective in the treatment of various cancers and that PD-1 and CTLA-4 have been linked to the suppression of T-cell receptor signaling and co-stimulatory molecules. Further, the volume examines other agents, a number of cells, receptors and signaling molecules, that are also involved in the regulation of T-cell activation and extends the concept of immune checkpoints to “molecules and cells that negatively regulate T-cell activation”. Playing essential roles in immune homeostasis, they could offer new targets for cancer immunotherapy, and for the therapy of autoimmune diseases. Written by internationally respected scientists, this book will appeal to basic scientists, clinicians, drug development researchers, and advanced students alike.

This book presents the clinical scope of cancer immunotherapeutic agents for solid tumors and Hematologic malignancies, elaborates on the scientific details of their modes of action, and presents the impact of these agents on oncology, patients and the broader healthcare system. At present, cancer immunotherapies fall broadly into three categories: immune checkpoint inhibitors (ICIs), adoptive T cell therapies, and cancer vaccines which have distinct mechanisms of action. Immune checkpoint inhibitors rely upon disrupting tumor antigen recognition as self by the immune system through inhibition of checkpoint molecules. Adoptive T cell therapies involve the engineering of T cells ex vivo to target and destroy tumor cells. The first part of this book will provide an overview of the discovery and mechanistic details of the technology. The second part will be devoted to elaborating on the clinical outcomes, successes and limitations for specific tumor subtypes, which includes both solid tumors and hematologic malignances for both pediatric and adult populations. As such, the book offers a valuable resource for oncologists, hematologists, and all those seeking an up-to-date overview of cancer immunotherapies.

Get a quick, expert overview of the latest clinical information and guidelines for cancer checkpoint inhibitors and their implications for specific types of cancers. This practical title by Drs. Fumito Ito and Marc Ernstoff synthesizes the most up-to-date research and clinical guidance available on immune checkpoint inhibitors and presents this information in a compact, easy-to-digest resource. It’s an ideal concise reference for trainee and practicing medical oncologists, as well as those in research. Discusses the current understanding of how to best harness the immune system against different types of cancer at various stages. Helps you translate current research and literature into practical information for daily practice. Presents information logically organized by disease site. Covers tumor immunology and biology; toxicities associated with immune checkpoint inhibitors; and future outlooks. Consolidates today’s available information on this timely topic into one convenient resource.