Significance: Davenport et al. discovered that the chimeric antigen receptor (CAR) immune synapse structure is different from the T cell receptor (TCR) synapse. The CAR immune synapse formed a disorganized pattern of Lck and more rapidly recruited lytic granules compared with the TCR. The differing immune synapse correlated with faster killing of tumor target cells and detachment from dying tumor cells by CAR-T cells. These findings provide a mechanism whereby CAR-T cells can effectively reduce large tumor burden in patients. This study will form a basis upon which to compare future receptor design to modulate signaling and programming of cytotoxic CAR-T cells to improve treatment of solid cancers.
T cells follow a triphasic distinct pathway of activation, proliferation and differentiation before becoming functionally and phenotypically “exhausted” in settings of chronic infection, autoimmunity and in cancer. Exhausted T cells progressively lose canonical effector functions, exhibit altered transcriptional networks and epigenetic signatures and gain constitutive expression of a broad coinhibitory receptor suite. This review outlines recent advances in our understanding of exhausted T cell biology and examines cellular and molecular mechanisms by which a state of dysfunction or exhaustion is established, and mechanisms by which exhausted T cells may still contribute to pathogen or tumour control. Further, this review describes our understanding of exhausted T cell heterogeneity and outlines the mechanisms by which checkpoint blockade differentially engages exhausted T cell subsets to overcome exhaustion and recover T cell function.
20 October 2023 in Signal Transduction and Targeted Therapy
Glioblastoma, a rare, and highly lethal form of brain cancer, poses significant challenges in terms of therapeutic resistance, and poor survival rates for both adult and paediatric patients alike. Despite advancements in brain cancer research driven by a technological revolution, translating our understanding of glioblastoma pathogenesis into improved clinical outcomes remains a critical unmet need. This review emphasises the intricate role of receptor tyrosine kinase signalling pathways, epigenetic mechanisms, and metabolic functions in glioblastoma tumourigenesis and therapeutic resistance. We also discuss the extensive efforts over the past two decades that have explored targeted therapies against these pathways. Emerging therapeutic approaches, such as antibody-toxin conjugates or CAR T cell therapies, offer potential by specifically targeting proteins on the glioblastoma cell surface. Combination strategies incorporating protein-targeted therapy and immune-based therapies demonstrate great promise for future clinical research. Moreover, gaining insights into the role of cell-of-origin in glioblastoma treatment response holds the potential to advance precision medicine approaches. Addressing these challenges is crucial to improving outcomes for glioblastoma patients and moving towards more effective precision therapies.
Pediatric brain tumors are the leading cause of childhood cancer-related death. Immunotherapy is a powerful new approach for treating some refractory cancers; applying this 'fourth pillar' of cancer treatment to pediatric brain tumors is an exciting but challenging prospect. This review offers new perspectives on moving towards successful immunotherapy for pediatric brain tumors, focusing on pediatric high-grade glioma (HGG), a subgroup with universally poor outcomes. We cover chimeric antigen receptor T cell (CAR-T) therapy, vaccine therapy, and checkpoint inhibition in this context, and focus on the need for intimately understanding the growing brain and its immune system. We highlight the challenges associated with the application of immunotherapy in pediatric neuro-oncology, as well as the tissue-specific challenges to be overcome, to achieve improved outcomes.
Oncology immunotherapy has been a significant advancement in cancer treatment and involves harnessing and redirecting a patient’s immune response towards their own tumour. Specific recognition and elimination of tumour cells was first proposed over a century ago with Paul Erlich’s ‘magic bullet’ theory of therapy. In the past decades, targeting cancer antigens by redirecting T cells with antibodies using either bispecific T cell engagers (BiTEs) or chimeric antigen receptor (CAR) T cell therapy has achieved impressive clinical responses. Despite recent successes in haematological cancers, linked to a high and uniformly expressed CD19 antigen, the efficacy of T cell therapies in solid cancers has been disappointing, in part due to antigen escape. Targeting heterogeneous solid tumours with T cell therapies will require the identification of novel tumour specific targets. These targets can be found among a range of cell-surface expressed antigens, including proteins, glycolipids or carbohydrates. In this review, we will introduce the current tumour target antigen classification, outline existing approaches to discover novel tumour target antigens and discuss considerations for future design of antibodies with a focus on their use in CAR T cells.
4 April 2022 in Journal for ImmunoTherapy of Cancer
Genetically engineered T cells have been successfully used in the treatment of hematological malignancies, greatly increasing both progression-free and overall survival in patients. However, the outcomes of patients treated with Chimeric Antigen Receptor (CAR) T cells targeting solid tumors have been disappointing. There is an unmet clinical need for therapies which are specifically designed to overcome the challenges associated with solid tumors such as tumor heterogeneity and antigen escape. Genetic engineering employing the use of biological logic gating in T cells is an emerging and cutting-edge field that may address these issues. The advantages of logic gating include localized secretion of anti-tumor proteins into the tumor microenvironment, multi antigen targeting of tumors and a potential increase in safety when targeting tumor antigens which may not be exclusively tumor specific. In this review, we introduce the concept of biological logic gating and how this technology addresses some of the challenges of current CAR T treatment. We outline the types of logic gating circuits and finally discuss the application of this new technology to engineered T cells, in the treatment of cancer.