Abstract: Arrays of immunoglobulin binding proteins in plants or plant cells are provided. Such arrays comprise plants or plant cells transformed with polynucleotides encoding multiple different immunoglobulin binding proteins, or polypeptide components thereof. Methods are further provided for genetic segregation of the transformation events such that each transformant in an array is capable of producing progeny capable of expressing one or more immunoglobulin binding proteins, including multi-subunit proteins.

Abstract: Arrays of immunoglobulin binding proteins in plants or plant cells are provided. Such arrays comprise plants or plant cells transformed with polynucleotides encoding multiple different immunoglobulin binding proteins, or polypeptide components thereof. Methods are further provided for genetic segregation of the transformation events such that each transformant in an array is capable of producing progeny capable of expressing one or more immunoglobulin binding proteins, including multi-subunit proteins.

Abstract: Targeting molecules are provided for use in delivering imaging agents to epithelial tissue. The targeting molecule comprises a polypeptide that forms a closed covalent loop, contains at least three peptide domains having &bgr;-sheet character, each of the domains being separated by domains lacking &bgr;-sheet character. The targeting molecule specifically binds to a basolateral factor attached to a basolateral domain of an epithelial cell surface causing internalization of a linked imaging agent into the cells. The polypeptide or imaging agent may be linked to a peptide amino acid sequence that directs delivery of the imaging agent to a carcinoma cell, a nucleus, or an endoplasmic reticulum.

Abstract: Targeting molecules for use in delivering biological agents to non-polarized epithelial cells are disclosed. Upon delivery, the biological agent(s) are lethal to the epithelial cell. The targeting molecules may be used, for example, for the eradication of metastatic epithelial cells.

Abstract: Polypeptide targeting molecules are provided for use in delivering imaging agents to epithelial tissue. Upon delivery, the imaging agent(s) may remain within an epithelial cell or may undergo transepithelial transport via transcytosis. The targeting molecules may be used, for example, for diagnostic techniques. The polypeptide may be produced by recombinant methods, and forms a closed covalent loop, contains at least three peptide domains having &bgr;-sheet character which are separated by domains lacking &bgr;-sheet character, specifically binds to a basolateral factor attached to a basolateral domain of an epithelial surface causing uptake of a linked imaging agent into cells of the epithelial surface, and is not a full length dimeric Iga. Preferably, the polypeptide is a J chain polypeptide, or a J chain polypeptide linked to an immunoglobulin heavy chain without an immunoglobulin light chain.

Abstract: Targeting molecules for use in delivering biological agents to non-polarized epithelial cells are disclosed. Upon delivery, the biological agent(s) are lethal to the epithelial cell. The targeting molecules may be used, for example, for the eradication of metastatic epithelial cells.

Abstract: Targeting molecules for use in delivering imaging agents to epithelial tissue are disclosed. Upon delivery, the imaging agent(s) may remain within an epithelial cell or may undergo transepithelial transport via transcytosis. The targeting molecules may be used, for example, for diagnostic techniques. The targeting molecule is a polypeptide, which may be produced by recombinant methods, that forms a closed covalent loop, contains at least three peptide domains having .beta.-sheet character which are separated by domains lacking .beta.-sheet character, specifically binds to a basolateral factor attached to a basolateral domain of an epithelial surface causing uptake of a linked imaging agent into cells of the epithelial surface, and is not a full length dimeric Iga. Preferably, the polypeptide is a J chain polypeptide, or a J chain polypeptide linked to an immunoglobulin heavy chain without an immunoglobulin light chain.