Histidine-Engineered Antibody Light Chain for pH-Dependent Recycling
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Solution Overview
Problem
Current methods for producing bispecific antibodies face challenges in creating a suitable light chain component that can effectively associate with heavy chains, and therapeutic antibodies often require high doses due to target-mediated clearance, necessitating more efficient antibody recycling and pH-dependent binding properties.
Innovation Solution
Genetically modified non-human animals, such as mice, are engineered to express antibodies with pH-dependent binding capabilities by modifying the immunoglobulin light chain sequence to include histidine residues in the CDR3 region, allowing for reduced binding at acidic pH and enhanced recycling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If therapeutic antibodies are administered to achieve desired efficacy, then antigen binding affinity is improved, but target-mediated clearance increases leading to reduced antibody recycling
Solution Approach 1:
The patent applies dynamics by making the antibody-antigen binding reversible and pH-dependent. The antibody maintains strong binding at neutral pH (blood circulation) but dissociates at acidic pH (endosomal compartment), enabling dynamic control of the binding interaction. This allows the antibody to be recycled after delivering its therapeutic effect, improving efficiency without compromising antigen binding affinity.
Solution Approach 2:
The patent changes the pH parameter of the binding environment to control antibody behavior. By engineering histidine residues into the light chain CDR3 region, the antibody's binding affinity becomes dependent on pH conditions. At neutral pH (7.4), binding is strong; at acidic pH (5.0-6.0), binding dissociates, enabling endosomal escape and antibody recycling.
2Reliability
If high doses of therapeutic antibodies are administered, then desired efficacy is achieved, but target-mediated clearance increases requiring higher doses
Solution Approach 1:
The patent implements discarding and recovering by enabling the antibody to dissociate from the antigen in the endosomal compartment (discarding) and be recycled back to circulation (recovering). The pH-dependent binding allows the antibody to be temporarily discarded in endosomes at acidic pH, then recovered when it returns to neutral pH in circulation, reducing the total quantity of antibody needed for therapeutic efficacy.
3Ease of manufacture
If a common light chain is used for bisspecific antibodies, then ease of manufacture is improved, but finding a light chain that associates with both heavy chains becomes problematic
Solution Approach 1:
The patent applies universality by creating a light chain with enhanced adaptability to associate with multiple different heavy chains. By engineering histidine residues into the light chain CDR3 region, the light chain gains versatility to bind different heavy chain specificities while maintaining a single common sequence, simplifying bispecific antibody production.
Solution Approach 2:
The patent changes the amino acid composition parameter of the light chain by introducing histidine residues at specific positions in the CDR3 region. This parameter change enhances the light chain's ability to accommodate different heavy chain partners, improving compatibility without requiring multiple different light chain sequences.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The modified antibodies exhibit a significant decrease in dissociative half-life at acidic pH, leading to improved recycling and reduced immunogenicity, potentially lowering the required dosage and maintaining antigen binding affinity.
Implementation Method 1
Antibodies having a heterodimeric heavy chain component (e.g., bisspecific antibodies) are desirable as therapeutic antibodies. But making bisspecific antibodies having a suitable light chain component that can satisfactorily associate with each of the heavy chains of a bisspecific antibody has proved problematic.
Implementation Method 2
If the chances of immunogenicity need to be minimized, the modifications preferably result in sequences that are present in known human light chain sequences, such that proteolytic processing is unlikely to generate a T cell epitope
Data Source
AI summary
A genetically modified non-human animal is provided, wherein the non-human animal expresses an antibody repertoire capable of pH dependent binding to antigens upon immunization. A genetically modified non-human animal is provided that expresses human immunoglobulin light chain variable domains derived from a limited repertoire of human immunoglobulin light chain variable gene segments that comprise histidine modifications in their germline sequence. Methods of making non-human animals that express antibodies comprising histidine residues encoded by histidine codons introduced into immunoglobulin light chain nucleotide sequences are provided.