Using genetically modified human cells for cell-based therapy, powerful as it may be, is limited in the type of output a sophisticated gene circuit can produce. Most often, the eventual output of an implanted cell is the production and secretion of a therapeutic protein. Yet as proteins can’t easily enter cells, this therapeutic protein has to perform its actions outside of cells, limiting the type of proteins which can be utilized. Exosomes are natural lipid vesicles (bubbles) produced by all cells and mainly used for intercellular communication.
Combining these two types of information, we set out to utilize exosomes for selective mRNA (the instructions for protein production) transport in a publication published in Nature Communications this year. Modifiying human cells as well as their exosomes allowed us to transport functional mRNA into other cells which then produced the protein it coded for. As a demonstration of our system, we used it to transport therapeutic mRNA into the brain of mice to treat neurodegenerative Parkinson’s disease, a feat that wouldn’t have been possible with conventional secreted protein.