Abstract B061: Harnessing stem cell-engineered CAR-NKT cells for universal low-toxicity autoimmune therapy

The future of TCR-Treg therapies is renewables.

Cell therapy has longstanding roots in haematopoietic stem cell transplantation and early immune cell transfers in infectious disease and transplantation, where patient- or donor-derived cells have achieved therapeutic benefit in selected contexts. The modern era has been driven largely by oncology, with engineered modalities such as tumour-infiltrating lymphocytes, CAR-T cells and TCR-engineered T cells delivering transformative responses but requiring complex, costly manufacturing. These platforms are now being adapted for autoimmune diseases to induce durable, antigen-specific immune tolerance, yet broad application is limited by safety concerns, process complexity and access. Non-engineered cell therapies for autoimmunity, including mesenchymal stem cells, polyclonal regulatory T cells and tolerogenic dendritic cells, have shown acceptable safety and proof-of-principle for immune re-education, but clinical responses have been modest and inconsistent, with limited scalability. Engineered approaches such as CAR-T cells can induce reversible B cell depletion in B cell-mediated rheumatic diseases but only addresses antibody-driven pathology and not T cell-mediated autoimmunity. TCR-engineered Tregs have emerged as a promising antigen-specific strategy, offering localized, antigen-linked suppression with bystander tolerance. Preclinical and early clinical data suggest superior potency, stability and disease control compared with polyclonal Tregs at similar or lower doses, but translation is constrained by the rarity and fragility of Tregs and by labour-intensive, CAR-T-like manufacturing. This review highlights emerging solutions for closed, automated and decentralised production, and discusses allogeneic approaches using gene-edited or banked Tregs with HLA engineering or matching. Together, these advances support the development of scalable, "off-the-shelf" TCR-Treg products with potential to provide safe, affordable tolerance-restoring therapies for autoimmune disease.

An allogeneic CD19 targeted Engineered Treg approach for treating B cell mediated autoimmune diseases 2260315

CD19 CAR T cells have demonstrated promising efficacy in SLE by deeply depleting B cells, but these autologous cell therapies are expensive to deploy, come with significant toxicity risks, and lack the ability to control additional immune cell functions driving autoreactive B cell generation and lupus pathogenesis. We developed GNTI-350, an allogeneic hypoimmune CD19 CAR—engineered regulatory T cell (CAR19 EngTreg) therapy, which leverages stable FOXP3 expression, a CD19 CAR for selective targeting, and a rapamycin-inducible IL-2 signaling complex to sustain Treg function. Persistence of GNTI-350 is enabled by Immune Evasion Engineering (IEE), a hypoimmune technology that allows MHC-deficient allogeneic cell therapies to evade host NK cell clearance. Human CAR19 EngTregs expressed canonical Treg markers, suppressed T cell proliferation, blocked B cell differentiation into plasma cells, and depleted CD19+ B cells in humanized mice with minimal inflammatory cytokine release versus conventional CD19 CAR T cells. In the SLE123 mouse model, CAR19 mEngTregs persisted >4 months, lowered autoantibodies, improved kidney pathology, and reduced the levels of T follicular helper (Tfh) and germinal center (GC) B cells - potentially showing a reinforcement of T follicular regulatory (Tfr) cell function. These data show that GNTI-350 can safely achieve a durable immune reset and may provide superior therapeutic benefit over CAR-T approaches to patients with B cell—driven autoimmune diseases. Venture capital, NIH Therapeutic Approaches to Autoimmunity (THER)

Engineering allogeneic type 1 regulatory T cells: a scalable, off-the-shelf platform for restoring immune tolerance

Type 1 regulatory T (Tr1) cells are IL-10–producing CD4+ regulatory T cells that play a central role in maintaining peripheral immune tolerance. Prior investigations of autologous Tr1 cell-based therapies have demonstrated clinical promise in graft-versus-host disease (GvHD), but widespread clinical application has been constrained by challenges in scaling cell production. TRX103 is an engineered, allogeneic Tr1 cell therapy manufactured using a fully compliant, current Good Manufacturing Practice-compatible process. TRX103 is generated by pooling engineered CD4+ T cells from three healthy donors that have been transduced with a lentiviral vector encoding human IL-10 and a truncated human nerve growth factor receptor, CD271. In vitro, off-the-shelf TRX103 suppressed effector T cell proliferation and inhibited pro-inflammatory cytokine production by monocytes from both healthy donors and patients with Crohn’s disease. In vivo, TRX103 homed to intestinal tissues and prevented disease development in a xenogeneic GvHD model. Phenotypic and functional analyses of TRX103 revealed the acquisition of a distinct cellular identity characterized by reduced expression of activation and immune synapse–associated molecules and minimal allogeneic stimulatory capacity. Together, these findings define a distinct immunomodulatory profile for TRX103 and support its clinical development as a scalable allogeneic cell therapy for immune-mediated diseases. TRX103 is currently being evaluated in a Phase 1/2a study in treatment-refractory Crohn’s disease (NCT06721962) and a Phase I study for GvHD prevention in hematopoietic stem cell transplantation recipients (NCT06462365).

In vivo CAR‑T therapy: recent progress and future directions

CAR-T Cell Therapy: Manufacturing Platforms and Clinical Consequences.

Chimeric antigen receptor (CAR) T-cell therapy has transformed hematological cancer care, yet variability in efficacy, durability, and safety cannot be explained solely by antigen selection or patient factors. We propose that manufacturing platforms are active biological determinants of outcome. Viral vectors, used in all licensed products, provide stable genomic integration and durable expression but are limited by cost, cargo capacity, and centralized production. Nonviral strategies, including transposons, CRISPR knock-ins, and messenger RNA delivery, enable faster, less-expensive manufacturing with larger payloads, while introducing distinct safety and persistence profiles. This review presents a three-layer mechanistic framework that reframes manufacturing as biology: integration biology determines genomic risk and transgene stability; clonal fitness shapes persistence, dominance, and exhaustion; and epigenomic imprinting, influenced by gene transfer method, cytokines, and culture stress, preconfigures functional trajectories. Clinical observations link platform choice to immune recovery, where prolonged B-cell aplasia and delayed T-cell reconstitution contribute to infection-related nonrelapse mortality, and hematopoietic reserve at apheresis emerges as a practical predictor. Finally, manufacturing is positioned as the key to democratizing cell therapy. Decentralized, nonviral production aligned with regulatory standards may enable equitable access and transition CAR-T therapy from innovation to sustainable global care.

BCMA-CAR Natural Killer Cells Suppress Myeloma in Bone Marrow but Allow Emergence of Extramedullary Disease 2266680

Multiple myeloma (MM) is an aggressive blood cancer arising from plasma cells. B cell maturation antigen (BCMA)-targeted chimeric antigen receptor T cell (α-BCMA-CAR-T) immunotherapies currently provide life-saving treatment for MM patients. Unfortunately, severe toxicities along with the high cost and complexity of autologous CAR-T manufacturing remain important limitations. Novel research is underway to use CAR-expressing natural killer (NK) cells as an allogeneic CAR-T alternative, but studies have yet to evaluate long-term CAR-NK efficacy against MM. NK cells were isolated, expanded via feeder-cell stimulation, and engineered to express α-BCMA-CAR and IL-15 co-expression. The functional characteristics of α-BCMA-CAR-IL15-expressing NK cells were initially assessed in vitro, followed by long-term testing in a luciferase-expressing MM-xenograft mouse model to examine the persistence and therapeutic effect of α-BCMA-CAR-IL15 NK. α-BCMA-CAR NK cells have enhanced cytokine production and cytotoxicity against BCMA-high MM cells compared to untransduced NK cells, with IL-15 co-expression required for CAR-NK persistence. When injected into NSG mice, both α-BCMA-CAR and IL-15 expression were required for persistent restriction of MM growth. Despite near complete and sustained elimination of MM in hematopoietic tissues, long-term assessment of mice treated with α-BCMA-CAR-IL15 NK cells revealed the emergence of extramedullary disease (EMD) in the form of BCMA-positive MM plasmacytomas. This study showcases α-BCMA-CAR-IL15 NK cell therapy as a potent anti-MM therapeutic, achieving sustained MM elimination from the bone marrow and greatly extending survival in a MM-xenograft model. However, α-BCMA-CAR-IL15 NK cells appeared ineffective at eliminating extramedullary disease. By demonstrating the strengths and weaknesses of α-BCMA-CAR-IL15 cells, our study provides a valuable pre-clinical MM model for studying and developing interventions for aggressive MM-EMD. Canadian Institutes of Health Research Translational and Interventional Immunology (TI)