HIV has been caught on camera: A new video shows the virus passing from an infected cell into a new host, as it would during sexual transmission. The real-time video offers a new glimpse of exactly how HIV, or the human immunodeficiency virus, infects cells during intercourse. "We had this global idea of how HIV infects this tissue [of the genital tract]; but following something live is completely different," Morgane Bomsel, a molecular biologist at the Institut Cochin in Paris and a senior author of the study, said in a statement. "The precise sequence of events can be defined." For the video, the researchers created a model of genital tissue in a lab dish, which included the cells that line the genital mucous membranes, known as epithelial cells. The virus, which infects cells of the immune system, is labeled with a green fluorescent protein. In the video, a type of immune cell called a T cell is infected with HIV, and this cell comes into contact with epithelial cells. Once these cells are in contact, a pocket called a virological synapse forms, allowing viral particles to travel from the infected cell to the uninfected cell. In what looks like a shooting ray gun from a sci-fi movie, the HIV spurts from the T cell into the epithelial cell. The HIV doesn't actually infect the epithelial cell, but instead travels across the cell and is later gobbled up by macrophages, another type of immune cell that HIV targets. After about 20 days, HIV enters a latent or "dormant" stage, but it's still inside the macrophages, which makes the virus harder to target with drugs. A goal for new HIV prevention strategies would be "to act extremely early upon infection to avoid this reservoir formation" in the macrophages, Bomsel said. By shedding light on the early steps of HIV transmission, the new study may help researchers take steps toward this goal. One idea would be to make a vaccine that's active at the genital mucous membranes, "because you can't wait" to stop the spread of HIV, Bomsel said. The findings were described in a study published today (May 8) in the journal Cell Reports. Source
