Use of Cell Penetrating Peptides to Deliver Cargo in Protists

Algae and plankton are important both ecologically as a food chain base and economically as nutraceutical “factories”. Despite their importance, technologies to transfect genes or proteins are limited or nonexistent in many protist species of interest, probably because cell walls present a barrier to macromolecular passage. We are using a novel cell penetrating peptide (CPP) system as a means to overcome this barrier. CPPs are a class of short peptides that can cross the cell membrane and sometimes the cell wall in a variety of species. Membrane translocation by CPPs involves endocytosis as well as other mechanisms. CPPs can be linked in a variety of ways to desired cargos to cause their entry into cells. Microscopic imaging of protist cells treated with CPP linked to fluorescently labeled cargo demonstrates that CPPs can cause the association of cargo with cells while fluorescently labeled cargo‐only treatment does not cause extensive cargo association with cells. Using fluorescence microscopy, we are currently optimizing the type of CPP and the CPP‐cargo uptake procedure to find the best conditions for cargo delivery to protists. We are also attempting proteolytic treatment to eliminate cargo stuck to the cell exterior and allow flow cytometric measurements of true cargo entry. Success of our method will provide a new means for rapid introduction of macromolecules into protist cells, allowing both investigation of their cellular function and potential manipulation of economically important products. Support or Funding Information Mentor Protégé Research Program, College of Science and Mathematics, Kennesaw State University; Research Opportunity Award, Office of Research, Kennesaw State University This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .