Positron-emission tomography/ computed tomography images show the viral presence before and during treatment. Virus detection in the gastrointestinal tract decreases under treatment but is not completely eradicated. Image: Phil Santangelo.
Researchers have developed a noninvasive method to image simian immunodeficiency virus (SIV) replication in real-time, in vivo. This approach, reported in the journal Nature Methods, is based on immune positron-emission tomography/computed tomography (PET/CT) and allows for the capture of viral dynamics of SIV, the animal model of human HIV infection. This approach has application to the study of immunodeficiency virus pathogenesis and drug and vaccine development, and could have use with human patients to identify viral reservoirs — potentially leading to new treatments for HIV/AIDS.
Francois Villinger, a researcher in the Yerkes Research Center’s Microbiology and Immunology Division, and Philip Santangelo, a researcher in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University, led the study with their respective teams and collaborators at the Emory School of Medicine. Using the nonhuman primate model of human HIV infection, their approach uncovered previously unappreciated sites of viral replication, such as in nasal tissue.
In addition, the methodology captured the wide variation in viral replication levels within select organs, including sections of the gastrointestinal tract, whether or not the subject was taking antiretroviral therapy. Finally, the methodology allows for repeat analysis of the viral dynamics, during acute infection, anti-viral therapy and upon cessation of therapy.
“Use of the technique could lead to a better understanding of viral dynamics in the body, which could help target new generations of therapeutics and diagnostics,” explained Santangelo. “This could help us find the regions where the virus is replicating and allow us to focus molecular diagnostics on the areas that are really important.” —YERKES RESEARCH CENTER