Genome-Edited T Cell Therapies

Gene editing to enhance the efficacy of cancer cell therapies

Adoptive T cell therapies have shown impressive signals of activity, but their clinical impact could be enhanced by technologies to increase T cell potency and diminish the cost and labor involved in manufacturing these products. Gene editing platforms are under study in this arena to (1) enhance immune cell potency by knocking out molecules that inhibit immune responses; (2) deliver genetic payloads into precise genomic locations and thereby enhance safety and/or improve the gene expression profile by leveraging physiologic promoters, enhancers, and repressors; and (3) enable off-the-shelf therapies by preventing alloreactivity and immune rejection. This review discusses gene editing approaches that have been the best studied in the context of human T cells and adoptive T cell therapies, summarizing their current status and near-term potential for translation.

CRISPR/Cas9 Technology as a Modern Genetic Manipulation Tool for Recapitulating of Neurodegenerative Disorders in Large Animal Models

BACKGROUND

Neurodegenerative diseases are often the consequence of alterations in structures and functions of the Central Nervous System (CNS) in patients. Despite obtaining massive genomic information concerning the molecular basis of these diseases and since the neurological disorders are multifactorial, causal connections between pathological pathways at the molecular level and CNS disorders development have remained obscure and need to be elucidated to a great extent.

OBJECTIVE

Animal models serve as accessible and valuable tools for understanding and discovering the roles of causative factors in the development of neurodegenerative disorders and finding appropriate treatments. Contrary to rodents and other small animals, large animals, especially non-human primates (NHPs), are remarkably similar to humans; hence, they establish suitable models for recapitulating the main human's neuropathological manifestations that may not be seen in rodent models. In addition, they serve as useful models to discover effective therapeutic targets for neurodegenerative disorders due to their similarity to humans in terms of physiology, evolutionary distance, anatomy, and behavior.

METHODS

In this review, we recommend different strategies based on the CRISPR-Cas9 system for generating animal models of human neurodegenerative disorders and explaining in vivo CRISPR-Cas9 delivery procedures that are applied to disease models for therapeutic purposes.

RESULTS

With the emergence of CRISPR/Cas9 as a modern specific gene-editing technology in the field of genetic engineering, genetic modification procedures such as gene knock-in and knock-out have become increasingly easier compared to traditional gene targeting techniques. Unlike the old techniques, this versatile technology can efficiently generate transgenic large animal models without the need to complicate lab instruments. Hence, these animals can accurately replicate the signs of neurodegenerative disorders.

CONCLUSION

Preclinical applications of CRISPR/Cas9 gene-editing technology supply a unique opportunity to establish animal models of neurodegenerative disorders with high accuracy and facilitate perspectives for breakthroughs in the research on the nervous system disease therapy and drug discovery. Furthermore, the useful outcomes of CRISPR applications in various clinical phases are hopeful for their translation to the clinic in a short time.

Industrializing engineered autologous T cells as medicines for solid tumours

Cell therapy is one of the fastest growing areas in the pharmaceutical industry, with considerable therapeutic potential. However, substantial challenges regarding the utility of these therapies will need to be addressed before they can become mainstream medicines with applicability similar to that of small molecules or monoclonal antibodies. Engineered T cells have achieved success in the treatment of blood cancers, with four chimeric antigen receptor (CAR)-T cell therapies now approved for the treatment of B cell malignancies based on their unprecedented efficacy in clinical trials. However, similar results have not yet been achieved in the treatment of the much larger patient population with solid tumours. For cell therapies to become mainstream medicines, they may need to offer transformational clinical effects for patients and be applicable in disease settings that remain unaddressed by simpler approaches. This Perspective provides an industry perspective on the progress achieved by engineered T cell therapies to date and the opportunities and current barriers for accessing broader patient populations, and discusses the solutions and new development strategies required to fully industrialize the therapeutic potential of engineered T cells as medicines.

Making sense of heritable human genome editing: Scientific and ethical considerations

Genome editing, particularly the use of CRISPR-Cas9-based methodologies, is revolutionizing biology through its impacts on research and the translation of these into applications in biomedicine. Somatic genome editing aimed at treating individuals with disease raises some significant ethical issues, but proposed heritable interventions, through the use of genome editing in gametes or embryos, raise a number of distinct social, ethical and political issues. This review will consider some proposed uses of heritable human genome editing (HHGE) and several of the objections to these that have been raised. Making sense of such proposed uses requires viewing HHGE as an assisted reproductive technology (ART) that, like preimplantation genetic testing (PGT) and mitochondrial replacement techniques (MRT), aims to prevent disease transmission during sexual reproduction, rather than acting as a therapy for an existing individual. Applications beyond the paradigm of disease prevention raise even more difficult scientific and ethical questions. Here, I will discuss various themes that are prominent in discussions of the science and ethics of HHGE, including impacts on human dignity and society, the language of HHGE used for public dialogue and the governance of HHGE.

Carry on editing

INTRODUCTION OR BACKGROUND

Genome editing facilitates alterations to DNA, large or subtle, in a precise fashion. In its most popular form it uses the programmable endonuclease system, CRISPR/Cas9. Edits can be made to any genome, including the human genome. This raises the possibility of genome editing in human embryos in both a research and reproductive context.

SOURCES OF DATA

All reports of genome editing in human embryos are included here, along with key papers examining the science and ethics of human genome editing.

AREAS OF AGREEMENT

As a basic research tool, genome editing promises to accelerate our understanding of genome biology. It also shows great promise as a means of combatting disease through so-called somatic genome editing.

AREAS OF CONTROVERSY

Genome editing could be used to prevent human disease transmission in a reproductive context. Such germ line interventions are opposed by some, for a number of reasons. Some of these reasons are discussed and a comparison is made with preimplantation genetic diagnosis (PGD).

GROWING POINTS

It is important that scientists, clinicians, bioethicists and other stakeholders engage widely with all those with an interest in genome editing.

AREAS TIMELY FOR DEVELOPING RESEARCH

In addition to offering new insights into human biology, basic (fundamental) research will deliver expertise allowing ever more precise and controllable genome editing methodologies and allied technologies. A range of clear and accessible ethical frameworks must be developed and scrutinized as part of a wider societal debate about possible applications of genome editing. In the UK, human reproductive genome editing can only take place if a change to primary legislation occurs. Inclusive discussions and assessments, involving difficult scientific and ethical concepts, must form part of any democratic decision.

Posttransplant chimeric antigen receptor therapy

Therapeutic T-cell engineering is emerging as a powerful approach to treat refractory hematological malignancies. Its most successful embodiment to date is based on the use of second-generation chimeric antigen receptors (CARs) targeting CD19, a cell surface molecule found in most B-cell leukemias and lymphomas. Remarkable complete remissions have been obtained with autologous T cells expressing CD19 CARs in patients with relapsed, chemo-refractory B-cell acute lymphoblastic leukemia, chronic lymphocytic leukemia, and non-Hodgkin lymphoma. Allogeneic CAR T cells may also be harnessed to treat relapse after allogeneic hematopoietic stem cell transplantation. However, the use of donor T cells poses unique challenges owing to potential alloreactivity. We review different approaches to mitigate the risk of causing or aggravating graft-versus-host disease (GVHD), including CAR therapies based on donor leukocyte infusion, virus-specific T cells, T-cell receptor-deficient T cells, lymphoid progenitor cells, and regulatory T cells. Advances in CAR design, T-cell selection and gene editing are poised to enable the safe use of allogeneic CAR T cells without incurring GVHD.

CAR-T cell therapy in ovarian cancer: from the bench to the bedside

Ovarian cancer (OC) is the most lethal gynecological malignancy and is responsible for most gynecological cancer deaths. Apart from conventional surgery, chemotherapy, and radiotherapy, chimeric antigen receptor-modified T (CAR-T) cells as a representative of adoptive cellular immunotherapy have received considerable attention in the research field of cancer treatment. CARs combine antigen specificity and T-cell-activating properties in a single fusion molecule. Several preclinical experiments and clinical trials have confirmed that adoptive cell immunotherapy using typical CAR-engineered T cells for OC is a promising treatment approach with striking clinical efficacy; moreover, the emerging CAR-Ts targeting various antigens also exert great potential. However, such therapies have side effects and toxicities, such as cytokine-associated and “on-target, off-tumor” toxicities. In this review, we systematically detail and highlight the present knowledge of CAR-Ts including the constructions, vectors, clinical applications, development challenges, and solutions of CAR-T-cell therapy for OC. We hope to provide new insight into OC treatment for the future.