Human CD4+CD25+ T cells expressing a chimeric antigen receptor against aberrant superoxide dismutase 1 trigger antigen-specific immunomodulation
- Cytotherapy. 2024 Feb;26(2):126-135. doi: 10.1016/j.jcyt.2023.11.007.
- 1. Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire, USA; Center for Synthetic Immunity, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire, USA.
- 2. Celdara Medical, LLC, Lebanon, New Hampshire, USA.
- 3. Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire, USA; Center for Synthetic Immunity, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire, USA. Electronic address: [email protected].
Background aims: Amyotrophic Lateral Sclerosis (ALS) is a fatal disease associated with motor neuron degeneration, accumulation of aggregated misfolded proteins and neuroinflammation in motor regions of the central nervous system (CNS). Clinical trials using regulatory T cells (Tregs) are ongoing because of Tregs' immunomodulatory function, ability to traffic to the CNS, high numbers correlating with slower disease in ALS and disease-modifying activity in ALS mouse models. In the current study, a chimeric antigen receptor (CAR) was developed and characterized in human Tregs to enhance their immunomodulatory activity when in contact with an ALS protein aggregate.
Methods: A CAR (DG05-28-3z) consisting of a human superoxide dismutase 1 (hSOD1)-binding single-chain variable fragment, CD28 hinge, transmembrane and co-stimulatory domain and CD3ζ signaling domain was created and expressed in human Tregs. Human Tregs were isolated by either magnetic enrichment for CD4+CD25hi cells (Enr-Tregs) or cell sorting for CD4+CD25hiCD127lo cells (FP-Tregs), transduced and expanded for 17 days.
Results: The CAR bound preferentially to the ALS mutant G93A-hSOD1 protein relative to the wild-type hSOD1 protein. The CAR Tregs produced IL-10 when cultured with aggregated G93A-hSOD1 proteins or spinal cord explants from G93A-hSOD1 transgenic mice. Co-culturing DG05-28-3z CAR Tregs with human monocytes/Macrophages inhibited production of tumor necrosis factor Alpha and reactive oxygen species. Expanded FP-Tregs resulted in more robust Tregs compared with Enr-Tregs. FP-Tregs produced similar IL-10 and less interferon gamma, had lower Treg-specific demethylated region methylation and expressed higher FOXP3 and CD39.
Conclusions: Taken together, this study demonstrates that gene-modified Tregs can be developed to target an aggregated ALS-relevant protein to elicit CAR-mediated Treg effector functions and provides an approach for generating Treg therapies for ALS with the goal of enhanced disease site-specific Immunomodulation.