Episomal Vectors for Safe Nuclear Reprogramming

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Solution Overview

Problem

Current methods for nuclear reprogramming of somatic cells to induce pluripotency face challenges such as variable efficiency, potential tumorigenicity from genetic modifications, and reliance on exogenous gene expression, which limits clinical applicability and differentiation potential.

Innovation Solution

The use of CRISPR-based technologies to modulate endogenous gene expression by activating embryonic stem cell-associated genes and suppressing somatic cell-specific or cell death-associated genes, allowing for faster and more efficient nuclear reprogramming without the need for exogenous gene expression.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If retroviral vectors are used for reprogramming, then reprogramming efficiency is improved, but tumorigenicity risk increases due to insertional mutagenesis

Engineering Contradiction:

Improvereprogramming efficiencyVSAvoidtumorigenicity risk

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent extracts and removes the integration function from the reprogramming vector system. By using non-integrating episomal vectors instead of retroviral vectors, the harmful insertional mutagenesis is eliminated while retaining the ability to deliver reprogramming factors. The episomal vectors replicate independently without integrating into host genomic DNA, thus resolving the contradiction between efficiency and safety.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent employs transient, non-persistent vector systems that deliver reprogramming factors temporarily without long-term genomic integration. The episomal vectors are designed to be lost during cell division or can be actively removed, providing a disposable approach that achieves reprogramming goals without leaving permanent genetic modifications that could cause tumorigenicity.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

2Productivity

If exogenous reprogramming factors are continuously expressed, then reprogramming efficiency is improved, but differentiation potential is reduced

Engineering Contradiction:

Improvereprogramming efficiencyVSAvoiddifferentiation potential

Core Design Contradiction:

ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent implements dynamic control of reprogramming factor expression through inducible promoter systems. The expression of exogenous reprogramming factors can be turned on during the reprogramming phase and then turned off when pluripotency is achieved. This dynamic regulation allows efficient reprogramming while subsequently enabling full differentiation potential by removing the suppressive effect of continuous factor expression.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent uses preliminary action by providing reprogramming factors temporarily during the critical reprogramming window, then removing them once pluripotency is established. This preliminary expression is sufficient to drive the reprogramming process without requiring continuous presence, thereby preserving the cell's natural differentiation capabilities afterward.

Inventive Principle:

Principle #10Preliminary action

3Productivity

If DNA-integrating vectors are used, then reprogramming efficiency is improved, but genetic stability is compromised

Engineering Contradiction:

Improvereprogramming efficiencyVSAvoidgenetic stability

Core Design Contradiction:

ProductivityVSStability of the object's composition

Solution Approach 1:

The patent extracts the integration capability from the vector system, using episomal vectors that maintain their DNA independently without integrating into the host genome. This eliminates the risk of insertional mutagenesis and genetic instability while still achieving efficient reprogramming through transient expression of reprogramming factors.

Inventive Principle:

Principle #2Taking out (Extraction)

4Productivity

If mRNA reprogramming is used, then reprogramming efficiency is improved, but method robustness decreases

Engineering Contradiction:

Improvereprogramming efficiencyVSAvoidmethod robustness

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent uses DNA-based episomal vectors that serve as stable templates for transcription of reprogramming factors. Instead of directly introducing mRNA, the system copies the reprogramming factors from stable DNA templates within the cells, providing both high efficiency and robustness. The DNA templates ensure consistent and sustained expression of reprogramming factors throughout the process.

Inventive Principle:

Principle #26Copying

Data Source

PatentUS20230313222A1Methods for nuclear reprogramming using synthetic transcription factors

Publication Date: 2023.10.05 LONZA WALKERSVILLE INC

AI summary

The current disclosure provides methods for reprogramming mammalian somatic cells by regulating the expression of endogenous cellular genes. Cellular reprogramming of somatic cells can be induced by activating the transcription of embryonic stem cell-associated genes (e.g., oct3/4) and suppressing the transcription of somatic cell-specific and/or cell death-associated genes. The endogenous transcription machinery can be modulated using synthetic transcription factors (activators and suppressors), to allow for faster, and more efficient nuclear reprogramming under conditions amenable for clinical and commercial applications. The current disclosure further provides cells obtained from such methods, along with therapeutic methods for using such cells for the treatment of diseases amendable to stem cell therapy, as well as kits for such uses.