Reengineering chimeric antigen receptor T cells for targeted therapy of autoimmune disease

Pemphigus

Pemphigus is a group of IgG-mediated autoimmune diseases of stratified squamous epithelia, such as the skin and oral mucosa, in which acantholysis (the loss of cell adhesion) causes blisters and erosions. Pemphigus has three major subtypes: pemphigus vulgaris, pemphigus foliaceus and paraneoplastic pemphigus. IgG autoantibodies are characteristically raised against desmoglein 1 and desmoglein 3, which are cell-cell adhesion molecules found in desmosomes. The sites of blister formation can be physiologically explained by the anti-desmoglein autoantibody profile and tissue-specific expression pattern of desmoglein isoforms. The pathophysiological roles of T cells and B cells have been characterized in mouse models of pemphigus and patients, revealing insights into the mechanisms of autoimmunity. Diagnosis is based on clinical manifestations and confirmed with histological and immunochemical testing. The current first-line treatment is systemic corticosteroids and adjuvant therapies, including immunosuppressive agents, intravenous immunoglobulin and plasmapheresis. Rituximab, a monoclonal antibody against CD20⁺ B cells, is a promising therapeutic option that may soon become first-line therapy. Pemphigus is one of the best-characterized human autoimmune diseases and provides an ideal paradigm for both basic and clinical research, especially towards the development of antigen-specific immune suppression treatments for autoimmune diseases.

Chimeric Antigen Receptors: A Cell and Gene Therapy Perspective

Chimeric antigen receptors (CARs) are synthetic receptors that reprogram T lymphocytes to target chosen antigens. The targeting of CD19, a cell surface molecule expressed in the vast majority of leukemias and lymphomas, has been successfully translated in the clinic, earning CAR therapy a special distinction in the selection of "cancer immunotherapy" by Science as the breakthrough of the year in 2013. CD19 CAR therapy is predicated on advances in genetic engineering, T cell biology, tumor immunology, synthetic biology, target identification, cell manufacturing sciences, and regulatory compliance-the central tenets of CAR therapy. Here, we review two of these foundations: the genetic engineering approaches and cell types to engineer.

CARs: Synthetic Immunoreceptors for Cancer Therapy and Beyond

Chimeric antigen receptors (CARs) are versatile synthetic receptors that provide T cells with engineered specificity. Clinical success in treating B-cell malignancies has demonstrated the therapeutic potential of CAR-T cells against cancer, and efforts are underway to expand the use of engineered T cells to the treatment of diverse medical conditions, including infections and autoimmune diseases. Here, we review current understanding of the molecular properties of CARs, how this knowledge informs the rational design and characterization of novel receptors, the successes and shortcomings of CAR-T cells in the clinic, and emerging solutions for the continued improvement of CAR-T cell therapy.

Meeting Report of the Pathogenesis of Pemphigus and Pemphigoid Meeting in Munich, September 2016

Autoimmune blistering diseases are a heterogeneous group of about a dozen complex disorders that are characterized by intraepidermal (pemphigus) and subepidermal blistering (pemphigoid diseases and dermatitis herpetiformis). The Pathogenesis of Pemphigus and Pemphigoid Meeting, organized by the Departments of Dermatology in Lübeck and Marburg and the Institute of Anatomy and Cell Biology, Munich, was held in September 2016 in Munich. The meeting brought together basic scientists and clinicians from all continents dedicating their work to autoimmune blistering diseases. Considerable advances have been made in describing incidences and prevalences of these diseases and linking comorbidities with autoantibody reactivities and clinical variants, for example, dipeptidyl peptidase-IV inhibitor-associated noninflammatory bullous pemphigoid. Although new entities are still being described, diagnosis of most autoimmune blistering diseases can now be achieved using standardized and widely available serological test systems. Various experimental mouse models of pemphigus and pemphigoid disease are increasingly being used to understand mechanisms of central and peripheral tolerance and to evaluate more specific treatment approaches for these disorders, such as molecules that target autoreactive T and B cells and anti-inflammatory mediators, that is, dimethyl fumarate, phosphodiesterase 4, and leukotriene B4 inhibitors in pemphigoid disorders, and chimeric antigen receptor T cells in pemphigus. Very recent experimental data about the immunopathology and the determinants of autoantibody formation and keratinocyte susceptibility in pemphigus were discussed. With regard to cellular mechanisms leading to the loss of cell-cell adhesion, new ideas were shared in the field of signal transduction. Major steps were taken to put the various partly contradictory and controversial findings about the effects of pemphigus autoantibodies and other inflammatory mediators into perspective and broaden our view of the complex pathophysiology of this disease. Finally, two investigator-initiated multicenter trials highlighted doxycycline and dapsone as valuable medications in the treatment of bullous pemphigoid.

Immune engineering: from systems immunology to engineering immunity

The smallpox vaccine represents the earliest attempt in engineering immunity. The recent success of chimeric antigen receptor T cells (CAR-T cells) in cancer once again demonstrates the clinical potential of immune engineering. Inspired by this success, diverse approaches have been used to boost various aspects of immunity: engineering dendritic cells (DCs), natural killer (NK) cells, T cells, antibodies, cytokines, small peptides, and others. With recent development of various high-throughput technologies (of which engineers, especially biomedical engineers/bioengineers contributed significantly), such as immune repertoire sequencing, and analytical methods, a systems level of understanding immunity (or the lack of it) beyond model animals has provided critical insights into the human immune system. This review focuses on recent progressed made in systems biology and the engineering of adaptive immunity.

Setting the target for pemphigus vulgaris therapy

Despite the rising incidence of autoimmunity, therapeutic options for patients with autoimmune disease still rely on decades-old immunosuppressive strategies that risk severe and potentially fatal complications. Thus, novel therapeutic approaches for autoimmune diseases are greatly needed in order to minimize treatment-related toxicity. Such strategies would ideally target only the autoreactive immune components to preserve beneficial immunity. Here, we review how several decades of basic, translational, and clinical research on the immunology of pemphigus vulgaris (PV), an autoantibody-mediated skin disease, have enabled the development of targeted immunotherapeutic strategies. We discuss research to elucidate the pathophysiology of PV and how the knowledge afforded by these studies has led to the preclinical and clinical testing of targeted approaches to neutralize autoantibodies, to induce antigen-specific tolerance, and to specifically eliminate autoreactive B cells in PV.

Induction of potent apoptosis by an anti-CD20 aptamer via the crosslink of membrane CD20 on non-Hodgkin's lymphoma cells

An anti-CD20 DNA aptamer was successfully generated by cell-SELEX, the crosslink of which can induce potent apoptosis in target cells.

Autoimmune Disease Manifestations in the Oral Cavity

Immune-related disorders of the oral cavity may occur as primary disease process, secondary to systemic disease or neoplasm, or as a reaction to medications and other agents. The entities represented within this group may vary significantly by severity, clinical presentation, microscopic presentation, and special testing results. The selected immune-related conditions of the oral cavity in this article are categorized and presented by their prototypical tissue reaction patterns: vesiculobullous, including acantholytic and subepithelial separation; psoriasiform; spongiotic; and lichenoid reaction patterns.

[What's new in dermatological research?]

Many research studies dedicated to skin have been published in 2016 in high impact factor journals. This article summarises a selection of research works published between December 2015 and September 2016. New insights into the understanding of the mechanisms involved in psoriasis and atopic dermatitis can lead to better management of these chronic inflammatory disorders. Moreover, a better understanding of the relation between the host and the environment could lead to new therapeutic strategies. Finally, new devices first dedicated to skin inflammatory diseases have been developed with success that could be extended to other chronic inflammatory disorders.

FVIII-specific human chimeric antigen receptor T-regulatory cells suppress T- and B-cell responses to FVIII

Replacement therapy with factor VIII (FVIII) is used in patients with hemophilia A for treatment of bleeding episodes or for prophylaxis. A common and serious problem with this therapy is the patient's immune response to FVIII, because of a lack of tolerance, leading to the formation of inhibitory antibodies. Development of tolerogenic therapies, other than standard immune tolerance induction (ITI), is an unmet goal. We previously generated engineered antigen-specific regulatory T cells (Tregs), created by transduction of a recombinant T-cell receptor (TCR) isolated from a hemophilia A subject's T-cell clone. The resulting engineered T cells suppressed both T- and B-cell effector responses to FVIII. In this study, we have engineered an FVIII-specific chimeric antigen receptor (ANS8 CAR) using a FVIII-specific scFv derived from a synthetic phage display library. Transduced ANS8 CAR T cells specific for the A2 domain proliferated in response to FVIII and ANS8 CAR Tregs were able to suppress the proliferation of FVIII-specific T-effector cells with specificity for a different FVIII domain in vitro. These data suggest that engineered cells are able to promote bystander suppression. Importantly, ANS8 CAR-transduced Tregs also were able to suppress the recall antibody response of murine splenocytes from FVIII knockout mice to FVIII in vitro and in vivo. In conclusion, CAR-transduced Tregs are a promising approach for future tolerogenic treatment of hemophilia A patients with inhibitors.