pH-Sensitive Immunoglobulin Sequences for Antibody Recycling
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Solution Overview
Problem
Existing immunoglobulin binding domains in therapeutic antibodies exhibit suboptimal pharmacokinetic features, such as rapid clearance and inefficient recycling, and there is a need for pH-dependent antigen binding and improved light chain association in bispecific antibodies.
Innovation Solution
Genetically modify non-human animals to introduce histidine residues into immunoglobulin loci, particularly in heavy and light chain variable domains, to enhance pH-dependent antigen binding and recycling efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional immunoglobulin binding domains are used in therapeutic antibodies, then the basic antibody structure and antigen binding function are maintained, but the pharmacokinetic features are suboptimal with rapid clearance and inefficient recycling
Solution Approach 1:
The patent applies parameter changes by modifying the amino acid sequence of immunoglobulin binding domains through germline engineering. Specifically, histidine residues are introduced at pH-sensitive positions in the variable domains of heavy and light chains, which changes the chemical properties of the antibody to enable pH-dependent binding and improved recycling through FcRn, thereby extending serum half-life
2Reliability
If immunoglobulin loci are genetically modified to contain histidine substitutions or insertions, then pH-dependent antigen binding and recycling efficiency are enhanced, but the genetic modification complexity increases
Solution Approach 1:
The patent applies universality by creating a germline-modified animal model where pH-sensitive histidine residues are introduced into immunoglobulin loci. This single genetic modification approach simultaneously achieves multiple functions: pH-dependent antigen binding, improved recycling efficiency, and extended serum half-life, eliminating the need for separate engineering steps for each function
Solution Approach 2:
The patent applies self-service by engineering the animal's germline to automatically produce immunoglobulins with pH-sensitive properties. The modified animals themselves serve as living factories that continuously generate therapeutic antibodies with the desired pH-dependent binding characteristics, eliminating the need for external modification of each antibody batch
3Reliability
If high doses of therapeutic antibodies are administered, then the therapeutic effect is enhanced, but the clearance rate increases and degradation is minimized less effectively
Solution Approach 1:
The patent applies parameter changes by modifying the pH-sensitive properties of immunoglobulin binding domains through histidine residue introduction. This changes the binding characteristics to enable pH-dependent interaction with FcRn, creating a recycling mechanism that reduces clearance and degradation, allowing lower doses to achieve the same therapeutic effect
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 animals produce immunoglobulins with enhanced serum half-life and improved recycling by promoting dissociation of antigen-binding proteins at different pH levels, reducing the need for high doses and minimizing degradation.
Implementation Method 1
Genetically modified non-human animals that express antibodies capable of binding to an antigen in a pH dependent manner. Genetically modified non-human animals that comprise immunoglobulin loci that are modified to contain at least one substitution or insertion of a codon encoding a protonatable amino acid.
Data Source
AI summary
Genetically modified non-human animals are provided that express an immunoglobulin variable domain that comprises at least one histidine, wherein the at least one histidine is encoded by a substitution of a non-histidine codon in the germline of the animal with a histidine codon, or the insertion of a histidine codon in a germline immunoglobulin nucleic acid sequence. Immunoglobulin genes comprising histidines in one or more CDRs, in an N-terminal region, and/or in a loop 4 region are also provided. Immunoglobulin variable domains comprising one or more histidines (e.g., histidine clusters) substituted for non-antigen-binding non-histidine residues. Non-human animals that are progeny of animals comprising modified heavy chain variable loci (V, D, J segments), modified light chain variable loci (V, J segments), and rearranged germline light chain genes (VJ sequences) are also provided. Non-human animals that make immunoglobulin domains that bind antigens in a pH-sensitive manner are provided.