Safety and tolerability of a single infusion of autologous ex vivo expanded regulatory T cells in adults with ulcerative colitis (ER-TREG 01): protocol of a phase 1, open-label, fast-track dose-escalation clinical trial

Adoptive Treg therapy with metabolic intervention via perforated microneedles ameliorates psoriasis syndrome

Regulatory T (T_reg) cells underlie multiple autoimmune disorders and potentialize an anti-inflammation treatment with adoptive cell therapy. However, systemic delivery of cellular therapeutics often lacks tissue targeting and accumulation for localized autoimmune diseases. Besides, the instability and plasticity of T_reg cells also induce phenotype transition and functional loss, impeding clinical translation. Here, we developed a perforated microneedle (PMN) with favorable mechanical performance and a spacious encapsulation cavity to support cell survival, as well as tunable channels to facilitate cell migration for local T_reg therapy of psoriasis. In addition, the enzyme-degradable microneedle matrix could release fatty acid in the hyperinflammatory area of psoriasis, enhancing the T_reg suppressive functions via the fatty acid oxidation (FAO)-mediated metabolic intervention. T_reg cells administered through PMN substantially ameliorated psoriasis syndrome with the assistance of fatty acid-mediated metabolic intervention in a psoriasis mouse model. This tailorable PMN could offer a transformative platform for local cell therapy to treat a variety of diseases.

Enhancing Regulatory T Cells to Treat Inflammatory and Autoimmune Diseases

Regulatory T cells (Tregs) control immune responses and are essential to maintain immune homeostasis and self-tolerance. Hence, it is no coincidence that autoimmune and chronic inflammatory disorders are associated with defects in Tregs. These diseases have currently no cure and are treated with palliative drugs such as immunosuppressant and immunomodulatory agents. Thereby, there is a great interest in developing medical interventions against these diseases based on enhancing Treg cell function and numbers. Here, we give an overview of Treg cell ontogeny and function, paying particular attention to mucosal Tregs. We review some notable approaches to enhance immunomodulation by Tregs with therapeutic purposes including adoptive Treg cell transfer therapy and discuss relevant clinical trials for inflammatory bowel disease. We next introduce ways to expand mucosal Tregs in vivo using microbiota and dietary products that have been the focus of clinical trials in various autoimmune and chronic-inflammatory diseases.

Regulatory T cells as a therapeutic approach for inflammatory bowel disease

Foxp3⁺ T regulatory (Treg) cells suppress inflammation and are essential for maintaining tissue homeostasis. A growing appreciation of tissue-specific Treg functions has built interest in leveraging the endogenous suppressive mechanisms of these cells into cellular therapeutics in organ-specific diseases. Notably, Treg cells play a critical role in maintaining the intestinal environment. As a barrier site, the gut requires Treg cells to mediate interactions with the microbiota, support barrier integrity, and regulate the immune system. Without fully functional Treg cells, intestinal inflammation and microbial dysbiosis ensue. Thus, there is a particular interest in developing Treg cellular therapies for intestinal inflammatory disease, such as inflammatory bowel disease (IBD). This article reviews some of the critical pathways that are dysregulated in IBD, Treg cell mechanisms of suppression, and the efforts and approaches in the field to develop these cells as a cellular therapy for IBD.

Autologous regulatory T-cell transfer in refractory ulcerative colitis with concomitant primary sclerosing cholangitis

OBJECTIVE

Ulcerative colitis (UC) is a chronic, debilitating immune-mediated disease driven by disturbed mucosal homeostasis, with an excess of intestinal effector T cells and an insufficient expansion of mucosal regulatory T cells (Tregs). We here report on the successful adoptive transfer of autologous, ex vivo expanded Tregs in a patient with refractory UC and associated primary sclerosing cholangitis (PSC), for which effective therapy is currently not available.

DESIGN

The patient received a single infusion of 1×10⁶ autologous, ex vivo expanded, polyclonal Tregs per kilogram of body weight, and the clinical, biochemical, endoscopic and histological responses were assessed 4 and 12 weeks after adoptive Treg transfer.

RESULTS

The patient showed clinical, biochemical, endoscopic and histological signs of response until week 12 after adoptive Treg transfer, which was associated with an enrichment of intestinal CD3⁺/FoxP3⁺ and CD3⁺/IL-10⁺ T cells and increased mucosal transforming growth factor beta and amphiregulin levels. Moreover, there was marked improvement of PSC with reduction of liver enzymes. This pronounced effect lasted for 4 weeks before values started to increase again.

CONCLUSION

These findings suggest that adoptive Treg therapy might be effective in refractory UC and might open new avenues for clinical trials in PSC.

TRIAL REGISTRATION NUMBER

NCT04691232.

Targeting cytokines in inflammatory bowel disease

Targeting cytokines in inflammatory bowel disease (IBD) is a useful clinical approach. Potential therapies for IBD include regulatory T cell transfer to restore cytokine balance, blocking proinflammatory cytokines (e.g., IL-12 and IL-23) or their receptors (sIL-6R and IL-36R), or inhibiting signaling kinases (e.g., JAK). An emerging trend in IBD therapy is to combine several anti-cytokine agents simultaneously.

Cell-based therapies for rheumatoid arthritis: opportunities and challenges

Rheumatoid arthritis (RA) is the most common immune-mediated inflammatory disease characterized by chronic synovitis that hardly resolves spontaneously. The current treatment of RA consists of nonsteroidal anti-inflammatory drugs (NSAIDs), glucocorticoids, conventional disease-modifying antirheumatic drugs (cDMARDs), biologic and targeted synthetic DMARDs. Although the treat-to-target strategy has been intensively applied in the past decade, clinical unmet needs still exist since a substantial proportion of patients are refractory or even develop severe adverse effects to current therapies. In recent years, with the deeper understanding of immunopathogenesis of the disease, cell-based therapies have exhibited effective and promising interventions to RA. Several cell-based therapies, such as mesenchymal stem cells (MSC), adoptive transfer of regulatory T cells (Treg), and chimeric antigen receptor (CAR)-T cell therapy as well as their beneficial effects have been documented and verified so far. In this review, we summarize the current evidence and discuss the prospect as well as challenges for these three types of cellular therapies in RA.