Chimeric Polypeptide Spacer Segmentation for CAR Expression

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Solution Overview

Problem

Current chimeric antigen receptors (CARs) face challenges in achieving optimal expression and antigen-binding efficiency on the cell surface, which limits their therapeutic effectiveness in treating diseases such as cancers and autoimmune disorders.

Innovation Solution

The development of a chimeric polypeptide comprising an antigen-binding region, a transmembrane region, and a spacer region with a stalk region and a stalk extension region, where the stalk extension region has fewer dimerization sites and is homologous to the stalk region, enhancing surface expression and antigen-binding efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional spacer region is used in chimeric polypeptides, then the basic structure is maintained, but surface expression and antigen-binding efficiency are suboptimal

Engineering Contradiction:

Improvesurface expressionVSAvoidspacer structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The spacer region is divided into two distinct segments: a stalk region (s) and a stalk extension region (s'-n). This segmentation allows each region to perform specialized functions - the stalk region provides structural support with dimerization sites, while the extension region optimizes spacing and orientation for enhanced surface expression and antigen binding without excessive complexity

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the spacer are given different properties: the stalk region contains dimerization sites for stable assembly, while the stalk extension region has reduced or absent dimerization sites to prevent excessive aggregation. This local differentiation optimizes both surface expression and functional activity

Inventive Principle:

Principle #3Local quality

2Reliability

If the spacer region is extended to improve antigen binding, then antigen-binding efficiency increases, but the risk of non-specific interactions increases

Engineering Contradiction:

Improveantigen-binding efficiencyVSAvoidnon-specific interactions

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The stalk extension region is designed with different dimerization site characteristics compared to the stalk region. By reducing or eliminating dimerization sites in the extension region while maintaining them in the stalk region, the structure achieves extended spacing for improved antigen binding while preventing excessive non-specific interactions through localized dimerization control

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The invention modifies the dimerization potential parameter along the spacer structure. The stalk region maintains high dimerization potential for stable complex formation, while the stalk extension region has reduced dimerization potential to optimize the balance between extended antigen binding and prevention of non-specific interactions

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS20230414661A1Polypeptide compositions comprising spacers

Publication Date: 2023.12.28 PRECIGEN INC

AI summary

Disclosed herein are methods and compositions including antigen-binding polypeptides comprising a stalk region and a stalk extension region. In some cases, the antigen-binding compositions comprising the stalk extension region has increased expression on a cell surface and, in some cases, has increased antigen-binding efficiency. A subject antigen binding polypeptide can be a chimeric antigen receptor (CAR).