Chimaeric Surrogate Light Chains for Pre-B Cell Development
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Solution Overview
Problem
Current methods for producing chimaeric antibodies in non-human transgenic vertebrates do not adequately address the earlier B-cell stages, particularly the pre-BII stage, where species-matching of human V regions with VpreB and mu constant regions is crucial for efficient B-cell development and antibody maturation.
Innovation Solution
The introduction of human VpreB and λ5 genes into non-human vertebrates, such as mice and rats, to form species-matched surrogate light chains with chimaeric heavy chains, facilitating the formation of pre-B-cell receptors and promoting B-cell development by ensuring appropriate pairing of human variable regions with human VpreB and non-human vertebrate constant regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If human V regions are used in chimaeric heavy chains with non-human constant regions, then antibody production capability is improved, but B-cell development efficiency deteriorates due to species mismatching at the pre-BII stage
Solution Approach 1:
The patent applies local quality by making the VpreB component human while keeping the constant region non-human. This creates a chimaeric pre-BCR where only the variable region portion (VpreB) is species-matched to the human V region of the heavy chain, while the constant region (Cμ) remains non-human to maintain endogenous control. This localized species-matching resolves the contradiction by ensuring proper pairing at the critical interface without requiring complete humanization.
Solution Approach 2:
The patent creates an asymmetric chimaeric structure in the pre-BCR where the VpreB component is human and the Cμ component is non-human. This asymmetric composition allows the human VpreB to properly interact with the human V region of the heavy chain while the non-human Cμ maintains compatibility with the non-human vertebrate's endogenous antibody production machinery.
2Adaptability or versatility
If endogenous non-human constant regions are used to harness endogenous control, then control of antibody generation is improved, but pre-B-cell receptor formation efficiency deteriorates due to species mismatching
Solution Approach 1:
The patent applies local quality by introducing human VpreB specifically at the variable region interface of the pre-BCR, while maintaining non-human constant regions elsewhere. This localized humanization ensures proper species-matching for V region pairing without compromising the endogenous control provided by non-human constant regions.
Solution Approach 2:
The human VpreB acts as an intermediary component that bridges the human V region of the chimaeric heavy chain with the non-human constant region system. It mediates the interaction between human and non-human components, enabling efficient pre-BCR formation while preserving endogenous control mechanisms.
3Reliability
If species-matched surrogate light chains are introduced, then pre-B-cell development is improved, but system complexity increases due to additional transgenic modifications
Solution Approach 1:
The patent applies local quality by introducing human VpreB specifically into the surrogate light chain complex where it is needed for species-matching with human V regions. This targeted modification minimizes the scope of transgenic changes while achieving the desired improvement in pre-B-cell development.
Solution Approach 2:
The human VpreB component serves multiple functions: it enables species-matched pairing with human V regions, maintains pre-BCR stability, and allows proper B-cell development. This multi-functional element reduces the need for multiple separate modifications, thereby managing system complexity.
Data Source
AI summary
The present invention relates inter alia to improvements in the production of chimaeric antibodies in non-human transgenic vertebrates such as mice and rats bearing one or more chimaeric antibody transgenes. In particular, the invention provides for improved non-human vertebrates and cells in which VpreB has been species-matched with the variable region of the chimaeric antibodies. Also, embodiments also provide for species-matching of the entire surrogate light chain for efficient pairing with chimaeric heavy chains during B-cell development in vivo in a non-human transgenic vertebrate setting.