Engineered Retrons Enhance HDR Genome Editing

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Solution Overview

Problem

The efficiency of homology-directed repair (HDR)-dependent precise genome editing remains unsatisfactory due to challenges in delivering sufficient levels of donor DNA template intracellularly.

Innovation Solution

Recombinant retrons with genetic modifications are used to enhance the production of msDNA as a DNA donor template, improving the functionality and properties of retrons for HDR-dependent genome editing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If physical tethering methods are used to deliver donor DNA to the DSB site, then delivery efficiency is improved, but the overall HDR efficiency remains unsatisfactory

Engineering Contradiction:

Improvedonor DNA delivery efficiencyVSAvoidHDR editing efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent uses retron-derived msDNA as an intermediary carrier to deliver the donor DNA template to the DSB site. The msDNA is produced intracellularly by the retron system (comprising retron reverse transcriptase and retron non-coding RNA), serving as a self-replicating intermediate that naturally accumulates at the target site, thereby improving both delivery efficiency and overall HDR editing efficiency without requiring external physical tethering methods

Inventive Principle:

Principle #24Intermediary (Mediator)

2Quantity of substance

If donor DNA template is provided exogenously, then HDR can occur, but intracellular concentrations are insufficient for efficient editing

Engineering Contradiction:

Improvedonor DNA template amountVSAvoidHDR editing efficiency

Core Design Contradiction:

Quantity of substanceVSProductivity

Solution Approach 1:

The patent implements a self-service system where the retron components (retron reverse transcriptase and retron non-coding RNA) are delivered to the cell and autonomously produce msDNA intracellularly. The system self-replicates and self-delivers the donor DNA template to the DSB site without requiring continuous external supply, thereby achieving sufficient intracellular concentrations for efficient HDR editing

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The retron components are delivered and establish intracellular production capability before the DSB is induced. The msDNA is pre-produced and accumulated within the cell, so when the DSB occurs, the donor template is already available at high concentrations at the target site, eliminating the need for simultaneous delivery of large amounts of donor DNA

Inventive Principle:

Principle #10Preliminary action

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 use of recombinant retrons increases the concentrations of msDNA, thereby enhancing the efficiency of HDR-dependent genome editing by providing an effective donor DNA template.

Implementation Method 1

a retron reverse transcriptase and an engineered retron non-coding RNA that creates RT DNA

Methodology Applied

Scientific EffectReverse transcription:

Data Source

PatentUS20250154533A1Engineered retrons and methods of use

Publication Date: 2025.05.15 RENAGADE THERAPEUTICS MANAGEMENT INC

AI summary

Disclosed are engineered retrons and methods of use such as to modify the genome of a host (e.g., mammalian) cell by delivering the engineered retron or the encoded ncRNA in vitro or in vivo to the host (e.g., mammalian) cell.