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Updated: Nov 18, 2025
Spatial and Temporal Control of T Cell Activation Using a Photoactivatable Agonist
Published on: April 25, 2018
Spatial Regulation of T-Cell Signaling by Programmed Death-Ligand 1 on Wireframe DNA Origami Flat Sheets
Trixy Fang1, Jonatan Alvelid2, Joel Spratt1
1Department of Medical Biochemistry and Biophysics, Karolinska Institute, 171 65 Stockholm, Sweden.
Abstract:
Programmed Death-1 (PD-1) is a coinhibitory receptor expressed on activated T cells that suppresses T-cell signaling and effector functions. It has been previously shown that binding to its ligand PD-L1 induces a spatial reorganization of PD-1 receptors into microclusters on the cell membrane. However, the roles of the spatial organization of PD-L1 on PD-1 clustering and T-cell signaling have not been elucidated. Here, we used DNA origami flat sheets to display PD-L1 ligands at defined nanoscale distances and investigated their ability to inhibit T-cell activation in vitro. We found that DNA origami flat sheets modified with CD3 and CD28 activating antibodies (FS-α-CD3-CD28) induced robust T-cell activation. Co-treatment with flat sheets presenting PD-L1 ligands separated by ∼200 nm (FS-PD-L1-200), but not 13 nm (FS-PD-L1-13) or 40 nm (FS-PD-L1-40), caused an inhibition of T-cell signaling, which increased with increasing molar ratio of FS-PD-L1-200 to FS-α-CD3-CD28. Furthermore, FS-PD-L1-200 induced the formation of smaller PD-1 nanoclusters and caused a larger reduction in IL-2 expression compared to FS-PD-L1-13. Together, these findings suggest that the spatial organization of PD-L1 determines its ability to regulate T-cell signaling and may guide the development of future nanomedicine-based immunomodulatory therapies.
Insights
The spatial arrangement of PD-L1 ligands on DNA origami sheets dictates their impact on T-cell signaling. Specifically, a 200 nm separation of PD-L1 inhibited T-cell activation, suggesting a role for ligand spacing in immunomodulation.
Area of Science:
- Immunology
- Nanotechnology
- Cell Biology
Background:
- Programmed Death-1 (PD-1) is a receptor on T cells that suppresses immune responses.
- Its ligand, PD-L1, binding to PD-1 causes receptor reorganization into microclusters.
- The precise role of PD-L1 spatial organization in PD-1 clustering and T-cell signaling remains unclear.
Purpose of the Study:
- To investigate how the nanoscale spatial organization of PD-L1 affects T-cell activation and signaling.
- To explore the potential of DNA origami nanostructures for precise control of immune cell interactions.
Main Methods:
- Utilized DNA origami flat sheets to display PD-L1 ligands at controlled nanoscale distances (13 nm, 40 nm, 200 nm).
- Co-cultured these nanostructures with T cells activated by anti-CD3 and anti-CD28 antibodies.
- Assessed T-cell signaling inhibition, PD-1 nanoclustering, and Interleukin-2 (IL-2) expression.
Main Results:
- T-cell activation was induced by DNA origami sheets with CD3/CD28 antibodies.
- PD-L1 ligands spaced at ~200 nm (FS-PD-L1-200), but not at 13 nm or 40 nm, inhibited T-cell signaling.
- Inhibition increased with higher ratios of FS-PD-L1-200 to activating antibodies.
- FS-PD-L1-200 induced smaller PD-1 nanoclusters and greater IL-2 reduction compared to FS-PD-L1-13.
Conclusions:
- The spatial organization of PD-L1 is a critical determinant of its immunomodulatory function.
- Nanoscale spacing of PD-L1 influences PD-1 clustering and downstream T-cell signaling.
- Findings provide a basis for developing nanomedicine-based immunomodulatory therapies targeting T-cell activation.
