Site‐Selective Tyrosine Reaction for Antibody‐Cell Conjugation and Targeted Immunotherapy

Abstract

Targeted immunotherapies capitalize on the exceptional binding capabilities of antibodies to stimulate a host response that effectuates long‐lived tumor destruction. One example is the conjugation of immunoglobulins (IgGs) to immune effector cells, which equips the cells with the ability to recognize and accurately kill malignant cells through a process called antibody‐dependent cellular cytotoxicity (ADCC). In this study, a chemoenzymatic reaction is developed that specifically functionalizes a single tyrosine (Tyr, Y) residue, Y296, in the Fc domain of therapeutic IgGs. A one‐pot reaction that combines the tyrosinase‐catalyzed oxidation of tyrosine to o‐quinone with a subsequent [3+2] photoaddition with vinyl ether is employed. This reaction installs fluorescent molecules or bioorthogonal groups at Y296 of IgGs or the C‐terminal Y‐tag of an engineered nanobody. The Tyr‐specific reaction is utilized in constructing monofunctionalized antibody‐drug conjugates (ADCs) and antibody/nanobody‐conjugated effector cells, such as natural killer cells or macrophages. These results demonstrate the potential of site‐selective antibody reactions for enhancing targeted cancer immunotherapy.

Efficacy and safety of antibody–drug conjugates in the treatment of urothelial cell carcinoma: a systematic review and meta-analysis of prospective clinical trials

“…The linker itself is currently believed to be non-toxic, but its stability significantly influences the subsequent toxicity of the payload ( Donaghy, 2016 ). In terms of the antibodies, site-selective monofunctionalization of IgG enables construction of ADCs carrying a single cytotoxic drug on the heavy chain, facilitating targeted cancer therapy ( Chen et al, 2023 ). Furthermore, engineering modifications of the ADCs to integrate defined quantities of the payload molecules at predetermined antibody sites allow creation of uniform populations of ADCs, leading to improved therapeutic windows, enhanced efficacies, and reduced toxicities ( Donaghy, 2016 ).…”

DataSheet1.pdf

“…The linker itself is currently believed to be non-toxic, but its stability significantly influences the subsequent toxicity of the payload (Donaghy, 2016). In terms of the antibodies, site-selective monofunctionalization of IgG enables construction of ADCs carrying a single cytotoxic drug on the heavy chain, facilitating targeted cancer therapy (Chen et al, 2023). Furthermore, engineering modifications of the ADCs to integrate defined quantities of the payload molecules at predetermined antibody sites allow creation of uniform populations of ADCs, leading to improved therapeutic windows, enhanced efficacies, and reduced toxicities (Donaghy, 2016).…”