“For a long time, EVs were thought of as a nonspecific garbage disposal mechanism,” said Jessica Tanis, assistant professor in the Department of Biological Sciences at the University of Delaware.
As it turns out, nothing could be further from the truth.
Scientists have learned that EVs, despite their extremely small size, have enormous signaling potential and play a critical role in communication between cells. They carry unique “cargos” of proteins, nucleic acids and other materials from the cell that released them. The transfer of these bioactive molecules by EVs is essential for the development, and contributes to the progression, of conditions such as cancer and neurodegenerative diseases.
“My lab is working on increasing our understanding of these tiny vesicles that can give you a glimpse into what’s going on in a particular cell,” said Tanis, whose team was recently awarded a $1.8 million National Institutes of Health (NIH) grant for this research.
“Remarkably, an individual cell can release multiple populations of EVs, each containing different cargos. We hope that our findings will provide new insights into how a cell packages and releases these distinct subsets of EVs. What are the cargos in each particular EV subtype? What determines which EV a cargo is loaded into? What are the functions of the different EVs?”
Those are among the questions her research group, which includes graduate and undergraduate students and a postdoctoral researcher, is seeking to answer. The NIH grant, “Elucidating biogenesis and cargo sorting mechanisms for discrete extracellular vesicle subpopulations,” will support the research project for five years.
Tanis works with a worm model, C. elegans, using fluorescently labeled proteins and powerful microscopes housed at UD’s Bioimaging Center to identify individual EVs. Doctoral student Michael Clupper said the research is possible only because of the highly sophisticated imaging equipment available at the center, which is part of the Delaware Biotechnology Institute.
Clupper came to UD for graduate school and began working on a project in Tanis’ lab involving a protein potentially linked to Alzheimer’s disease. When he discovered the protein packaged into EVs, his research shifted its focus to this new area — and a new skill he’s developed in working with the Bioimaging Center’s instruments.
“Few research institutions have the means to image EVs,” Clupper said. “We’re very fortunate at UD. The generalized term for these scopes is ‘super-resolution microscopes’ because they let you image down to a single molecule level.”