Gal4 TAD Chimeric mRNA for Accelerated Cell Lineage Conversion
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Solution Overview
Problem
Current mRNA reprogramming methods for cell lineage conversion are inefficient and require multiple transfections over several weeks, making them labor-intensive and costly, and are challenging to apply to cell types like blood cells due to low transfection efficiency and the need for sustained delivery.
Innovation Solution
The use of synthetic mRNAs encoding chimeric transcription factors with a heterologous peptide sequence derived from the carboxy-terminus of the Gal4 transcription factor enhances the activity of reprogramming factors, allowing for faster and more efficient lineage conversion, including dedifferentiation into induced pluripotent stem cells, through a reduced transfection regimen.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If current mRNA reprogramming methods are used for cell lineage conversion, then cell conversion can be achieved, but the process is inefficient and requires multiple transfections over several weeks
Solution Approach 1:
The patent modifies the transcriptional activity parameter by fusing reprogramming factors to the Gal4 transactivation domain, which has potent transactivation capabilities. This parameter change in transcriptional strength accelerates the reprogramming process, reducing it from several weeks to a few days while maintaining conversion efficiency
Solution Approach 2:
The invention creates composite transcription factors by fusing reprogramming factors (Oct4, Sox2, Klf4, c-Myc) with the Gal4 transactivation domain. This composite structure combines the DNA-binding capability of reprogramming factors with the enhanced transactivation power of Gal4 TAD, resulting in accelerated epigenetic remodeling and faster lineage conversion
2Productivity
If multiple transfections are performed to achieve sustained delivery of reprogramming factors, then conversion efficiency improves, but the process becomes labor-intensive and costly
Solution Approach 1:
The patent employs lentiviral vectors to deliver reprogramming factors in advance, establishing sustained expression before the reprogramming process begins. This preliminary action eliminates the need for repeated transfections, simplifying the protocol while maintaining efficient conversion
Solution Approach 2:
The lentiviral delivery system ensures continuous expression of reprogramming factors throughout the reprogramming process. This continuous action maintains the necessary transcriptional drive for epigenetic remodeling without requiring intermittent re-delivery, reducing procedural complexity
3Productivity
If mRNA transfection is used for cell reprogramming, then lineage conversion can be achieved, but transfection efficiency is low for certain cell types like blood cells
Solution Approach 1:
The patent uses lentiviral vectors as an intermediary delivery system that efficiently transduces difficult-to-transfect cell types like blood cells. The viral vector mediates gene delivery by infecting cells and integrating reprogramming factors into the genome, bypassing the limitations of direct mRNA transfection
Solution Approach 2:
The invention replaces the mechanical transfection process (physical or chemical mRNA delivery) with a biological delivery system (lentiviral transduction). This substitution leverages the virus's natural infection mechanism, which is highly efficient for blood cells and other difficult-to-transfect cell types
Data Source
AI summary
Methods for accelerated cell lineage conversion and the treatment of patients with the lineage converted cells are provided. The methods include the steps of transfecting a cell with a composition that includes at least one synthetic mRNA encoding a chimeric protein that corresponds to an engineered fusion of a transcription factor and an heterologous peptide sequence derived from the C-terminal TAD of Gal4. The TAD domain enhances the epigenetic remodeling activity of the chimeric protein increasing the speed of lineage conversion. The converted cells may be used for research or administered to a human or animal patient as a therapy. In one preferred embodiment, the reprogramming of a somatic cell to pluripotency is accelerated by using a cocktail of mRNAs expressing a combination of wild-type or engineered reprogramming factors where Oct4 and/or Sox2 and/or Nanog are expressed as Gal4 TAD chimeras.