COMPOSITIONS AND METHODS FOR IDENTIFYING, CHARACTERIZING, OPTIMIZING AND USING LIGANDS TO TRANSCYTOTIC MOLECULES

摘要

The invention provides compositions and methods, including screening assays, for obtaining ligands (targeting elements) directed to a target molecule that undergoes apical endocytosis, reverse transcytosis, and/or basolateral exocytosis. Further provided are methods of identifying molecules that specifically bind a transcytotic molecule. Further provided are methods of identifying phage displaying a polypeptide, and determining the sequence of the polypeptide, that gives phage the ability to penetrate a layer of epithelial cells. Such polypeptides may confer paracellular transporting properties and/or transcytotic properties.