Targeted Bioactivity of Membrane-Anchored TNF by an Antibody-Derived TNF Fusion Protein

Abstract

We describe the generation and characterization of a fusion protein consisting of a humanized anti-fibroblast-activating protein (anti-FAP) Ab and human TNF replacing the IgGI CH2/CH3 Fc domain. The construct was generated by recombinant DNA technology and preserved its IgG1-derived dimeric structure with the TNF molecule linked as a dimer. Expression in CHO cells was optimized in serum-free medium under GMP conditions to achieve production levels up to 15 mg/liter. Recognition of the FAP Ag by the construct was as good as that by the parental anti-FAP Ab. TNF signaling was induce able via both TNF receptor types. When acting in solution, the Ab-linked TNF dimer exhibited a 10- to 20-fold lo..