Scientists have finally recreated in a test tube the first moments of infection by the human immunodeficiency virus (HIV). The infection takes place deep within cells, so understanding the first steps of this process has been difficult to investigate.
HIV has caused the worst pandemic of the last century, leading to the deaths of 33 million people globally. Today, about 38 million people live with the virus. This new research, published in Science, provides an unobstructed view of the infection and a new understanding of how HIV works.
"We are learning new things about one of the most significant pathogens that humans have ever encountered, and that is important," co-first authors Dr Devin Christiansen and Dr Barbie Ganser-Pornillos, from the University of Utah, said in a statement.
The research shows the role of the capsid (the virus's outer shell) is more complicated than previously thought. Thanks to advancements in electron microscopy, the team was able to visualize the 240 proteins that make up the outer shell.
Previously, it was assumed that the capsid was there to simply protect the genetic material inside. However, the new research suggests that it is more than just packaging and instead helps the infection process directly. They found that the capsid remains largely intact during the replication process, which is known as reverse transcription. When the team used genetic and biochemical methods to destabilize the capsid, the virus could no longer replicate effectively.
"This is different than in the textbooks," senior author Wesley Sundquist explained. "Our data indicate that the viral capsid plays an active and indispensable role in supporting efficient reverse transcription."
HIV was confirmed to be the cause of the acquired immunodeficiency syndrome (AIDS) over 35 years ago. Thanks to the tireless work of activists and scientists, anti-retroviral treatments now guarantee a healthy and long life to people living with the virus. People on effective treatment can get their viral load to an undetectable level, making it impossible for them to pass on the virus.
While the scientific progress has been impressive, people with HIV continue to suffer from stigma and discrimination. Access to treatment and education about the virus remains vital.