Individual Final Project

Programmable Anti-CD3 Oligomers Architectures to Decode and Control TCR Clustering

1. Background and Rationale T-cell activation is initiated when the T-cell receptor (TCR) and associated CD3 complex form nanoscale clusters at the cell membrane. Although anti-CD3 antibodies are widely used to activate T cells and redirect them in cancer therapy, conventional antibodies poorly control cluster size, geometry, spacing, and signaling strength because they are large, bivalent, and structurally inflexible. Nanobodies (VHHs) or scFvs offer a strong alternative. This project uses anti-CD3 nanobodies as programmable building blocks to precisely control TCR clustering and define how receptor geometry determines T-cell activation.

2. Hypothesis The magnitude and quality of T-cell activation are governed not only by CD3 binding affinity, but by the valency, spacing, and geometry of clustered TCR-CD3 complexes. Engineered multivalent nanobody scaffolds can tune these parameters and generate predictable signaling outputs.

3. Research Objective Engineer anti-CD3 nanobody-based proteins with defined valency and spacing to identify the structural rules of productive TCR clustering and apply them to safer T-cell activation platforms.

4. Expected Outcomes This project is expected to establish:

• Minimum valency threshold for TCR activation
• Optimal nanoscale spacing for productive signaling
• Architectures that activate T cells strongly
• General design principles for receptor clustering biology

Group Final Project