Single Domain Antibodies Block CD40L Without Platelet Aggregation
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Solution Overview
Problem
Current anti-CD40L monoclonal antibodies used in clinical trials for autoimmune diseases and transplant rejection often cause thromboembolic complications due to platelet aggregation, limiting their effectiveness and leading to trial halts.
Innovation Solution
Development of novel antibody polypeptides with a single variable domain that specifically bind human CD40L, reducing platelet aggregation and inhibiting CD40L-CD40 interactions, while maintaining therapeutic efficacy for autoimmune and transplant-related diseases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional anti-CD40L monoclonal antibodies are used to treat autoimmune diseases and transplant rejection, then therapeutic efficacy is achieved, but thromboembolic complications occur due to platelet aggregation
Solution Approach 1:
The patent extracts only the essential antigen-binding function by using single variable domain antibodies (dAbs) instead of full IgG molecules. This removes the Fc region that would otherwise mediate platelet aggregation through FcγRIIa receptor binding, while preserving the ability to bind CD40L and block its interaction with CD40, thereby maintaining therapeutic efficacy without causing thromboembolic complications
Solution Approach 2:
The single variable domain antibody acts as an intermediary that blocks the interaction between CD40L and CD40 without triggering platelet aggregation. By using a minimal antibody structure (dAb) rather than a full antibody, it mediates the therapeutic effect of CD40L blockade while avoiding the harmful Fc-mediated platelet crosslinking that occurs with conventional antibodies
2Adaptability or versatility
If conventional monoclonal antibodies are used to block CD40L, then immune response modulation is achieved, but platelet aggregation is induced through FcgRIIa receptor ligation
Solution Approach 1:
The invention removes the Fc region from the antibody structure, retaining only the variable domain that is responsible for antigen binding. This extraction eliminates the ability to crosslink platelets via FcγRIIa receptors while preserving the ability to bind CD40L and modulate immune responses through blockade of the CD40-CD40L interaction
Solution Approach 2:
The single variable domain antibody is a simplified, minimal structure compared to full IgG molecules. This 'short-living' format (in terms of structural complexity rather than actual half-life) provides the necessary therapeutic function without the unnecessary Fc portion that causes platelet aggregation, making it a more efficient and safer therapeutic agent
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 antibody polypeptides effectively inhibit CD40L-CD40 interactions without causing thromboembolic events, providing a safer treatment option for autoimmune diseases and transplant rejection, with a specific binding affinity that competes with existing antibodies like BMS2h-572-633, offering a therapeutically effective EC50 range of 100 pM to 100 nM.
Implementation Method 1
Antibodies and fragments thereof that target CD40L... Exemplary antibody polypeptides are in the form of a domain antibody (dAb) that contains a single variable domain... The antibody polypeptides specifically bind human CD40L
Data Source
AI summary
Antibody polypeptides that specifically bind human CD40L are provided. The antibody polypeptides do not activate platelets. The antibody polypeptides are useful in the treatment of diseases involving CD40L activation, such as graft-related diseases and autoimmune diseases. The antibody polypeptides may be domain antibodies (dAbs) comprising a single VH or VK domain. The half-life of the antibody polypeptides may be increased by modifying the antibody polypeptides to be dual specific reagents that can also bind human serum albumin (HSA) or another antigen.