An interdisciplinary team of scientists from KU Leuven in Belgium has developed a new technique to examine how proteins interact with each other at the level of a single HIV viral particle. The technique allows scientists to study the life-threatening virus in detail and makes screening potential anti-HIV drugs quicker and more efficient. The technique can also be used to study other diseases.
Understanding how the human immunodeficiency virus (HIV) reproduces itself is crucial in the effort to fight the disease. Upon entering the bloodstream, HIV viral particles, or virions, 'highjack' individual immune cells. The virion binds to and then penetrates the immune cell. Once inside, the virion reprograms the genetic material of the immune cell to produce more HIV virions. In this way, HIV disables the disease-fighting 'bodyguards' in our blood and turns them into breeding machines for new HIV virions.
Integrase plays a key role throughout this whole process: "Integrase is the HIV protein that causes the genetic material of HIV to link to that of the hijacked cell. It ensures the programming of the human cell upon infection. In our study, we wanted to track integrase during the different stages of infection," explains postdoctoral researcher Jelle Hendrix (Department of Chemistry). The challenge is to do this at the level of a single virion: "HIV has multiple ways of doing the same thing. This is the case for cell penetration, for instance. So it is certainly useful to be able to see exactly how the individual HIV virions are behaving."
To achieve this, the researchers used single-molecule fluorescence imaging. They engineered a genetically modified HIV virion that was capable of infecting the cell but incapable of reproducing inside it. The virion was programmed to produce a fluorescent form of integrase. "This allowed us to examine the interactions of the florescent integrase under the light microscope both in vitro in a single HIV viri
|Contact: Dr. Jelle Hendrix|