UPenn drug-delivery vector aims to avoid immune attacks

Viruses have had a limited run in the drug delivery game because, while they can home in on tissues throughout the body, our immune systems are wired to mount defenses against them. Yet a group at the University of Pennsylvania has found a way to design viral vectors to elude a common immune function, making the engineered vectors potential vehicles for delivering drugs such as gene therapies to treat diseases.

The group engineered a lentiviral vector that expresses CD47, which is a protein that tells the immune system that a molecule is safe. In cell culture tests, this helped the vector to avoid becoming a meal for immune cells called macrophages as frequently as ones that did not express CD47, according to the group. The results of the experiments might mean that the vectors have the potential to deliver therapies to disease targets before they get devoured. The details of the discovery were presented this week at the 55th Annual Biophysical Society Meeting in Baltimore, MD.

"We would like to find a way to avoid the immune system and maximize the dose delivered to a tumor or diseased tissue," Dennis Discher, a professor at the University of Pennsylvania, said in a statement.

The research team confirmed that the lentiviral vector expressed CD47 by tagging them with a fluorescent protein and scanning them with atomic force microscopy. The vectors are hundreds of times smaller than cells, according to the group.

- here's the UPenn release