Humanized NOD Mouse Models for T1D Therapy Testing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current mouse models for type 1 diabetes (T1D), such as the non-obese diabetic (NOD) mouse, have limitations in translating genetic and pathogenic knowledge into clinically applicable therapies due to their inability to accurately represent human T1D susceptibility and respond to antibody-based interventions.
Innovation Solution
Development of genetically modified NOD mice with ablated classical MHC class I molecules and introduction of human HLA class I and II variants using CRISPR/Cas genome editing, allowing for the creation of improved humanized models that express specific HLA combinations relevant to T1D, enabling the testing of tailored clinical interventions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If NOD mice are used as a model for T1D, then the model exhibits spontaneous development of autoimmune diabetes, but the model does not accurately represent human T1D susceptibility and does not respond to antibody-based interventions
Solution Approach 1:
The patent segments the MHC system by selectively ablating specific MHC class I genes (H2-K1d, H2-D1b) while preserving others, and introduces specific human HLA class I and II variants. This segmentation allows the model to accurately represent specific human T1D susceptibility genotypes while maintaining the ability to respond to antibody-based interventions through preserved FcRn function.
Solution Approach 2:
The patent changes the genetic parameters of the mouse model by introducing human HLA class I (e.g., HLA-A*02:01, HLA-B*39:06) and class II variants, and by selectively knocking out specific MHC class I genes. This parameter change transforms the model from a general NOD mouse to a humanized model that accurately represents specific human T1D susceptibility patterns and responds to antibody therapies.
2Reliability
If β2m−/− mutation is used to create HLA-humanized mice, then human HLA class I variants can be expressed, but FcRn complex and IgG salvage pathways are disrupted making the model inappropriate for antibody-based therapy testing
Solution Approach 1:
The patent segments the MHC class I deficiency approach by using targeted gene ablation (H2-K1d−/−, H2-D1b−/−) instead of the global β2m−/− mutation. This segmentation preserves FcRn complex function and IgG salvage pathways while still enabling expression of human HLA class I variants, thus maintaining suitability for antibody-based therapy testing.
Solution Approach 2:
The patent uses FcRn as an intermediary element that must be preserved for the model to be suitable for antibody-based therapy testing. By choosing targeted MHC class I gene ablation over β2m−/− mutation, the model maintains FcRn function as a mediator of IgG salvage, enabling the model to respond to antibody-based interventions while still expressing human HLA class I variants.
3Measurement precision
If multiple MHC variants are ablated to create complete murine class I ablated mice, then independent contributions of MHC I variants can be separated, but the model complexity increases
Solution Approach 1:
The patent applies segmentation by creating a series of progressively ablated models (H2-K1d−/−, H2-D1b−/−, H2-K1d−/−H2-D1b−/−) rather than a single complex model. This segmented approach allows independent contribution of each MHC variant to be measured while managing complexity through a stepwise genetic modification strategy.
Solution Approach 2:
The patent applies local quality by creating models with specific, localized genetic modifications (targeted ablation of H2-K1d and/or H2-D1b) rather than global MHC deficiency. This allows precise measurement of the contribution of specific MHC class I variants to T1D pathogenesis while maintaining other immune functions.
Data Source
AI summary
The present disclosure relates to genetically modified non-obese diabetic (NOD) mice deficient in murine class I MHC molecules, class II molecules, or both class I and class II MHC molecules. The MHC knockout transgenic mice provided herein are useful, for example, for developing therapies for diabetes.