Figure 1.
Molecular schematics.
a. Hemi-COBRAs were constructed with an N-terminal antigen binding sdAb (anti-EGFR or anti-HEL) connected via a (G4SG3 S) linker to an inactive anti-CD3ε scFv, comprised of an active CD3 binding domain (VH or VL) connected to an inactive CD3 binding domain (VLi or VHi) using either a cleavable (SGGPGPAGMKGLPGS) or a non-cleavable (G4S)3 scFv linker. At the C-terminus of each hemi-COBRA is a His6-tagged anti-HSA sdAb connected by a (G4SG3 S) linker.b. T cell engaging positive controls were constructed with an N-terminal antigen binding sdAb (anti-EGFR or anti-HEL) connected via a (G4SG3 S) linker to an active anti-CD3ε scFv with a (G4 S)3 non-cleavable scFv linker. At the C-terminus of each hemi-COBRA is a His6-tagged anti-HSA sdAb connected by a (G4 SG3 S) linker.