What Progress Is Being Made in Fighting HIV?
Though a cure remains elusive, promising paths toward improved treatments are opening up.
HIV afflicts more than 35 million people and remains hard to treat, because the virus permanently inserts its own genome into human DNA. Here are some ways that researchers are using gene editing and other technologies in hopes of regaining momentum against the virus.
Temple University researchers have found a way to “snip” out the virus’s genes from cells. The researchers have done this only in human cell cultures; making the technique useful in medicine will require a way to deliver specialized snipping molecules to each cell infected with the virus. The study was published by the Proceedings of the National Academy of Sciences on July 21, and the snipping technique is demonstrated in a video.
Researchers are using gene therapy to defend the body from the virus. In a clinical trial administered by the University of Pennsylvania and Sangamo BioSciences, 12 patients were infused with 10 billion immune cells genetically engineered to resemble a rare HIV-resistant mutation. Four of the six patients who went off other antiretroviral therapy for several weeks saw decreased levels of HIV in their blood. A March article in the New England Journal of Medicine explains the methods and results of the trial.
Early Vaccine Work
Researchers at the University of Nebraska are testing a way to make an HIV vaccine that contains a genetically modified form of the virus in a weakened state. The researchers have modified the virus’s DNA so that it cannot reproduce without a type of amino acid that is not found in the body, says chemist Jiantao Guo. Scientists have used live weakened viruses in vaccines to ward off conditions like flu and measles for decades, but the approach has not been applied to HIV vaccines in human trials because the virus can copy itself quickly and could regain its ability to infect. Scientists published results of lab tests in the German Chemical Society’s Angewandte Chemie.
HIV uses proteins on its surface, known as “spikes,” to fuse with cells. These proteins must be open to infect cells, but they spend most of their time closed to hide from antibodies. This makes it harder for the body’s immune system to attack the virus. In a Science report published online in October, researchers from Weill Cornell Medical College in New York explain that they were able to watch these proteins change shape for the first time—a breakthrough that could lead to drugs or vaccines that target the spikes directly. The researchers used an imaging technique that involves inserting fluorescent molecules into the surface of the virus and seeing how it responded to a synthetic version of the protein that helps HIV bond to cells. A Nature paper shows the three-dimensional structure of one of the protein shapes.
Because of advances in antiretroviral therapy, the life expectancies of some HIV patients resemble those of the general population, studies in PLOS One and PLOS Medicine show. Even so, 1.6 million people died from AIDS-related causes in 2012. Researchers continue the search for promising avenues toward a cure or at least better treatments.
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