Enhancing theranostic potential of anti-mesothelin sdAb through site-specific labeling at a unique conserved lysine by molecular engineering.

ABSTRACT:

Background

Mesothelin is a 40 kDa glycoprotein overexpressed in several cancers, including triple-negative breast cancer (TNBC). The anti-mesothelin single-domain antibody (sdAb, or nanobody) A1 can serve as a radio-theranostic agent, but random DOTA conjugation on lysines yields heterogeneous products.

Results

We reengineered A1-His by directed mutagenesis to produce four single-lysine variants (A1K1-His, A1K2-His, A1K3-His, and A1K4-His). Each was site-specifically conjugated with p-SCN-Bn-DOTA, radiolabeled with ⁶⁸Ga, and evaluated by PET imaging in mice bearing HCC70 TNBC xenografts, followed by ex vivo biodistribution at 1 h post-injection. All mutants were successfully produced and site-specifically conjugated. A1K1-His showed lower conjugation efficiency an

SUBMITTER: N'Guessan E 

PROVIDER: S-EPMC12037457 | biostudies-literature | 2025 Apr

REPOSITORIES: biostudies-literature