New Footage Could Help Lead to an HIV Vaccine
In a world first, scientists have captured the moment an HIV-infected T cell passes the virus to a new host. The footage is now assisting scientists in better understanding the exact way HIV is transmitted and could lead to better prevention methods and even an eventual HIV vaccine.
The captivating moment HIV is transmitted to a new host is outlined in a new study published in Cell Reports. The footage portrays exactly how HIV is able to cross the genital mucous membranes in a new host as a way to reach immune system cells and complete the viral transmission.
The T cell in the video is infected with HIV and highlighted with bright green dye. In the recording, we see the T cell come into contact with a reconstructed urethral mucosal tissue found in the urethra. These cells are monitored in an in vitro model, which means it was created from components of living organisms but actually took place outside of a body, like in a petri dish.
As the HIV-infected T cell and the urinary tract tissue make contact, they form a pocket known as a virological synapse. The contact prompts the infected T cell to create more of the virus, which eventually passes from the T cell to the urinary tract cells due to the virological synapse.
But, the urinary tract cells are not the main target and remain uninfected even though there is contact. Rather, the HIV virus moves to specialized cells known as macrophages, which are waiting close by. Macrophages are immune system cells meant to attack an impending infection in order to rid it from the body. The macrophages envelop the virus, but instead of getting rid of it, they keep the virus inside them. The macrophages will generate and shed the virus for 20 days before entering a latent stage where they are still infected but no longer produce the virus.
As per the study, the entire process takes only one to two hours, and it ends after the infected T cell breaks contact with the urinary tract tissue.
The footage stunned the researchers. Senior researcher Morgane Bomsel, a molecular biologist at the Institut Cochin in Paris, said in a statement that they had this global idea of how HIV infects this tissue, but following something live is completely different. The precise sequence of events can be defined, and we were very surprised by them.
The footage and corresponding research unveiled a known behavior of HIV infections. The virus purposely looked for uninfected cells in the potential new host that were within close proximity to macrophages. This result suggests there is some sort of relationship or communication between the tissue lining of the urinary tract and these immune system cells.
Bomsel in the statement that they couldn’t have imagined that was possible before this kind of imaging.
The research also demonstrated how early HIV enters macrophages and forms reservoirs of the virus, a term used to describe infected macrophages in the latent, or non-virus-producing, stage. This proposes that an HIV vaccine would need to target the mucous membrane in the genital tract.
Thus, the team is now working on just that and said these important findings will help them reach their goal.
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