Methods and compositions related to soluble monoclonal variable lymphocyte receptors of defined antigen specificity

Inventors

Cooper, Max D. • Herrin, Brantley R. • Alder, Matthew N.

Assignees

UAB Research Foundation • University of Alabama at Birmingham UAB

Abstract

Disclosed are compositions and methods related to variable lymphocyte receptors (VLRs). More particularly, disclosed are a variety of antigen specific polypeptides, including soluble, monoclonal, and multivalent forms, as well as methods of using the polypeptides, antibodies that bind the antigen specific polypeptides, and nucleic acids, vectors and expression systems that encode the polypeptides. Antigen specific polypeptides that selectively bind pathogens, like anthrax, and carbohydrates, like blood group determinants, are specifically disclosed.

Core Innovation

The invention relates to a cell culture in which the culture medium comprises a plurality of multimers made from soluble, monoclonal antigen specific polypeptides. Each antigen specific polypeptide contains an N-terminal leucine rich repeat (LRRNT), one or more leucine rich repeats (LRRs), a C-terminal leucine rich repeat (LRRCT), and a connecting peptide comprising an alpha helix, defining the architecture of the soluble variable lymphocyte receptor (VLR) polypeptides.

The soluble monoclonal VLRs are secreted into the culture medium as multimers, including multivalent embodiments that bind more than one target. Documented examples include antigen-specific soluble VLRs that bind Bacillus anthracis BclA-CTD and show specificity relative to related Bacillus species.

The disclosure also describes binding to target proteins, target carbohydrates, and target pathogens, including gp120 for HIV and influenza, as well as blood group carbohydrates such as H-type determinants. The document further includes affinity and avidity modulation by modifying hypervariable residues using affinity maturation approaches including phage display, yeast display, bacterial display, and ribosome display.

Claims Coverage

The independent claim is directed to a cell culture whose culture medium contains multimers of soluble, monoclonal antigen specific polypeptides with a defined LRRNT–LRRs–LRRCT architecture and an alpha-helix connecting peptide. The remaining claim refinements narrow multimer composition, binding target scope, and optional affinity-maturation features and platforms.

The core inventive concept is soluble, monoclonal antigen specific polypeptide multimers with an LRRNT–LRRs–LRRCT arrangement and an alpha-helix connecting peptide secreted into a cell culture medium. The claim refinements further address multimer size, multivalency, target categories, affinity maturation platforms, and stable genomic integration of cDNA.

Stated Advantages

Documented Applications