Anti-CD300A Antibody Specificity for Ligand Blocking Without CD300C Binding

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Solution Overview

Problem

Existing anti-CD300A monoclonal antibodies face challenges in distinguishing between CD300A-R and CD300A-Q, and their ability to inhibit binding with ligands is unclear, making it difficult to examine CD300A function and treat diseases effectively without side effects.

Innovation Solution

Development of anti-CD300A monoclonal antibodies with specific CDR sequences (SEQ ID NOs: 7, 8, 15, 16, 23, 24) that selectively bind to CD300A-R and CD300A-Q, while avoiding CD300C, and inhibit the binding with ligands such as PS and PE.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If existing anti-CD300A monoclonal antibodies are used, then binding to CD300A is achieved, but inability to distinguish between CD300A-R and CD300A-Q and cross-reactivity with CD300C occurs

Engineering Contradiction:
Improvespecificity of antibody bindingVSAvoidcross-reactivity with CD300C
Core Design Contradiction:
Measurement precisionVSObject-generated harmful factors

Solution Approach 1:

The patent applies local quality by designing antibodies with specific CDR sequences (CDR-H1, CDR-H2, CDR-H3, CDR-L1, CDR-L2, CDR-L3) that are optimized to recognize specific epitopes on CD300A-R and CD300A-Q. The variable region sequences are carefully selected to provide localized binding specificity at the antigen-antibody interface, enabling discrimination between CD300A variants and avoidance of CD300C cross-reactivity.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent employs parameter changes by modifying the amino acid sequences in the CDR regions of the antibody variable domains. Specific substitutions, additions, or deletions in the CDR sequences alter the binding parameters (affinity, specificity) of the antibodies, enabling them to distinguish between CD300A-R, CD300A-Q, and CD300C while maintaining binding to the target antigens.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If anti-CD300A/C double antibody and anti-CD300C antibody are used in combination, then CD300A function can be examined indirectly, but method complexity and difficulty in direct function examination increase

Engineering Contradiction:
Improveability to examine CD300A functionVSAvoidcomplexity of antibody combination method
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts the CD300A-specific binding function from the complex antibody combination approach by developing monoclonal antibodies that directly and specifically bind to CD300A-R and CD300A-Q. This eliminates the need for using anti-CD300A/C double antibodies combined with anti-CD300C antibodies, simplifying the methodology while maintaining the ability to examine CD300A function directly.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If existing anti-CD300A antibodies are used, then binding to CD300A is achieved, but ability to inhibit binding with ligands is unclear

Engineering Contradiction:
Improvebinding capabilityVSAvoiduncertainty about ligand binding inhibition
Core Design Contradiction:
ReliabilityVSLoss of information

Solution Approach 1:

The patent develops antibodies that act as intermediaries by binding to CD300A-R and CD300A-Q and thereby blocking the interaction between these receptors and their natural ligands (phosphatidylserine and phosphatidylethanolamine). The antibodies serve as mediators that prevent ligand binding without requiring direct observation of the ligand-receptor interaction, providing reliable functional inhibition data.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 antibodies enable direct examination of CD300A function, reduce side effects, and provide therapeutic benefits for diseases like ischemic diseases, inflammatory diseases, and autoimmune diseases by specifically targeting CD300A-R and CD300A-Q without binding to CD300C.

Implementation Method 1

an anti-CD300A monoclonal antibody or an antigen-binding fragment thereof that binds to at least one of human CD300A-R and human CD300A-Q, does not bind to human CD300C

Methodology Applied
Scientific EffectAntigen-antibody binding:

Implementation Method 2

inhibiting the binding between human CD300A and a ligand thereof

Methodology Applied
Scientific EffectSteric blocking:

Data Source

PatentEP4703387A1Anti-human CD300a monoclonal antibody and antigen-binding fragment thereof
Publication Date: 2026.03.04 UNIV OF TSUKUBA
  • EP4703387A1 patent drawingFigure 1~2
  • EP4703387A1 patent drawingFigure 3
  • EP4703387A1 patent drawingFigure 4~6

AI summary

Provided is an antibody that binds to at least one of human CD300A-R and human CD300A-Q, does not bind to human CD300C, and inhibits the binding between human CD300A and a ligand thereof. An anti-human CD300A monoclonal antibody or an antigen-binding fragment thereof satisfies a requirement (i), (ii), or (iii) as described in the specification.