Identification of Novel Macropinocytosing Human Antibodies by Phage Display and High-Content Analysis.

Internalizing antibodies have great potential for the development of targeted therapeutics. Antibodies that internalize via the macropinocytosis pathway are particularly promising since macropinocytosis is capable of mediating rapid, bulk uptake and is selectively upregulated in many cancers. We hereby describe a method for identifying antibodies that internalize via macropinocytosis by screening phage-displayed single-chain antibody selection outputs with an automated fluorescent microscopy-based high-content analysis platform. Furthermore, this method can be similarly applied to other endocytic pathways if other fluorescent, pathway-specific, soluble markers are available.