Humanized TfR Animal Model for BBB Therapeutic Transport
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Solution Overview
Problem
Existing drug delivery approaches for targeting therapeutics across the blood-brain barrier (BBB) face inefficiencies and are compromised by CNS disease states that alter the integrity of the barrier, necessitating the need for improved animal models to test the efficacy of biologics for intracellularization and transport across the BBB.
Innovation Solution
Genetically modified non-human animals with recombinant genetic loci encoding a human Transferrin Receptor (TfR) protein and a knockout mutation in the α-glucosidase (GAA) locus are developed to facilitate the delivery of therapeutic molecules across the BBB, utilizing heterologous TfR proteins expressed on the surface of endothelial cells.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing drug delivery approaches are used to target therapeutics across the blood-brain barrier, then some level of therapeutic delivery is achieved, but the delivery efficiency is compromised and reliability is reduced due to altered barrier integrity in CNS disease states
Solution Approach 1:
The patent modifies the transferrin receptor protein sequence (parameter change) to enhance its ability to mediate therapeutic delivery across the blood-brain barrier. By altering specific amino acid residues in the TfR protein, the invention optimizes binding affinity and internalization efficiency, thereby improving both reliability and productivity of therapeutic delivery in the context of CNS disease states
Solution Approach 2:
The patent utilizes the transferrin receptor as an intermediary protein to facilitate therapeutic delivery. The TfR serves as a mediator that binds therapeutics and enables their transport across the blood-brain barrier through endocytosis, overcoming the barrier's protective function that normally prevents such delivery
2Adaptability or versatility
If heterologous human TfR protein is expressed in non-human animals, then the animals become useful models for testing therapeutic delivery, but the animal models differ from wild-type animals in terms of receptor expression
Solution Approach 1:
The patent segments the TfR protein into functional domains and selectively replaces specific segments (extracellular domain, transmembrane region, or cytoplasmic domain) with human-derived sequences. This segmentation approach allows the animal model to retain essential functions while incorporating human-relevant receptor characteristics for improved therapeutic delivery testing
Solution Approach 2:
The patent applies local quality modification by introducing human TfR protein expression specifically in the blood-brain barrier endothelial cells of the animal model, rather than uniformly across all tissues. This localized expression creates the necessary heterogeneity for effective therapeutic delivery testing while maintaining overall animal physiology
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 provide a reliable model for testing the delivery of therapeutics across the BBB, demonstrating effective intracellularization and transport of therapeutic molecules, such as GAA, to treat conditions like Pompe disease.
Implementation Method 1
The Tf receptor (TfR) is a target of some studies to deliver therapeutics intracellular and/or to the brain
Data Source
AI summary
Non-human animal cells and non-human animals comprising a humanized Tfrc gene, e.g., at an endogenous Tfrc locus, and methods of using such non-human animal cells and non-human animals are provided. Non-human animal cells or non-human animals comprising a humanized Tfrc gene express a human TfR protein or fragments thereof. Non-human animal cells and non-human animals comprising a humanized Tfrc gene and a knockout mutation in a Gaa gene, e.g., at an endogenous Gaa locus, and methods of using such non-human animal cells and non-human animals are also provided. Such animals are useful to screen anti-human-TfR binding protein based therapies of, e.g., Pompe disease.