K, cells, now let’s get in formation.
Biochemists at the University of Utah and protein engineers at the University of Washington have collaborated to design instructions to make human kidney cells into tiny, cargo-carrying packages that could one day be used to deliver therapeutics.
Their inspiration: viruses.
Here’s how Wes Sundquist of the University of Utah explained the work, published Wednesday in the journal Nature.
What inspiration did you take from viruses?
Viruses fall into two categories: viruses that have membranes around them and viruses that don’t. HIV is a case of a virus that has a membrane around it; it’s called an envelope virus. The virus is inside the cell, and it has to cross the membrane to infect another cell. The way envelope viruses do that is they wrap themselves in the membrane, then pinch it off behind themselves.
Where does the protein work at University of Washington come in?
At the same time we were studying that, they were figuring out how to design new proteins to do things they normally wouldn’t do. One of their goals was to get proteins to assemble into little cages. When they did that, they realized the little cages looked like little viruses. So they took a protein that wouldn’t normally assemble, changed the amino acid sequence and now it’s a little cage that looks like a virus. They contacted us to see if we could try to have this protein then wrap itself into a cell membrane.
How did you make that happen?
So it had to assemble into a little circle — they solved that problem. Then it has to bind to the membrane, and then it has to know how to pinch the membrane behind itself to actually leave the cell. We found that viruses like HIV basically use the host system: They steal the cell’s machinery to pinch the membrane behind themselves. So now we know how to recruit that machinery to use in the little cages.
What’s the application of that work?
This is early stage. But in principle, what viruses do is transfer information from one cell to another cell. That information, for example, can be RNA. We can now do that with an artificial system. So if we put an enzyme in the cages, we can transfer it to a new cell and detect the enzymatic activity in that next cell. Now, we’re interested in transferring nucleic acids. So instead of transferring an enzyme, you could transfer the gene that codes for the enzyme and make more of it.