Engineered Host Cells for High-Titer Recombinant Protein Expression

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Solution Overview

Problem

Methylotrophic yeasts, such as Pichia sp., face challenges in achieving high-yield expression of heterologous proteins, particularly in large-scale fermentation settings, due to limitations in transcript production with increasing copy numbers of integrated genes.

Innovation Solution

Engineered host cells with integrated expression cassettes containing non-native transcriptional elements and capable of integrating coding constructs without nuclease enzymes, allowing for high-titer expression of recombinant proteins by homologous recombination, and the use of inducible, regulated, or constitutive promoters for controlled protein expression.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the number of integrated copies is increased to increase protein expression, then protein expression increases, but transcript production reaches a limitation and cannot increase further

Engineering Contradiction:

Improveprotein expressionVSAvoidtranscript production

Core Design Contradiction:

ProductivityVSQuantity of substance

Solution Approach 1:

The patent changes the parameters of the expression system by introducing non-native transcriptional elements (heterologous promoters, terminators, signal sequences) that are not limited by the host cell's native transcriptional capacity. This allows the system to operate beyond the natural transcript production limits of the methylotrophic yeast, enabling continued increases in protein expression even when native transcript production plateaus.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite expression system by combining native methylotrophic yeast cellular machinery with non-native transcriptional elements from other organisms. This hybrid system leverages the metabolic capabilities of the methylotrophic yeast while incorporating transcriptional regulation mechanisms from heterologous sources, thereby overcoming the transcript production limitations of the native system.

Inventive Principle:

Principle #40Composite materials

2Adaptability or versatility

If multiple coding constructs are integrated into expression cassettes, then more heterologous genes can be expressed, but the cloning process becomes more complex and requires multiple steps

Engineering Contradiction:

Improvenumber of heterologous genes expressedVSAvoidcloning process complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the expression system into modular components: fixed expression cassettes containing non-native transcriptional elements and separate coding constructs containing heterologous genes. This segmentation allows independent optimization and assembly of different gene-cassette combinations, simplifying the cloning process while enabling expression of multiple heterologous genes through standardized modular units.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent creates universal expression cassettes with non-native transcriptional elements that can accept and drive expression of any heterologous coding sequence. These multi-functional cassettes serve as standardized platforms that can accommodate different genes, eliminating the need to design unique expression systems for each gene and significantly reducing cloning complexity across multiple protein production projects.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Productivity

If nuclease enzymes are used for integrating coding constructs, then integration efficiency improves, but extraneous DNA integration occurs and requires additional purification steps

Engineering Contradiction:

Improveintegration efficiencyVSAvoidintegration precision

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent employs the host cell's own homologous recombination machinery to integrate coding constructs into the expression cassettes. By designing coding constructs with homology regions matching the non-native transcriptional elements, the system utilizes the cell's endogenous repair mechanisms for precise integration, eliminating the need for external nuclease enzymes and avoiding off-target effects or extraneous DNA integration.

Inventive Principle:

Principle #25Self-service

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

This approach enables high-titer expression of recombinant proteins in microbial hosts, reducing the need for multiple cloning steps and minimizing extraneous DNA integration, resulting in a more efficient and 'cleaner' production system for proteins like food-based or therapeutic proteins.

Implementation Method 1

the engineered host cell is capable of integrating a plurality of coding constructs into the expression cassette without requiring a nuclease enzyme

Methodology Applied

Scientific EffectHomologous recombination:

Data Source

PatentUS20240209383A1Systems and methods for high yielding recombinant microorganisms and uses thereof

Publication Date: 2024.06.27 CLARA FOODS

AI summary

Provided are systems and methods for production of recombinant proteins in engineered microorganisms. The systems and methods provide high-titer expression of recombinant proteins in large scale production and are particularly useful for expressing heterologous proteins in a microbial host, such as food-based proteins or other protein types such as therapeutic proteins and enzymes. Disclosed are also kits for making the same.