DISRUPTED JIGSAW: HIV (red pieces in this conceptual drawing) normally attaches to protein projections on immune cells (white pieces). By removing the projections, scientists hope to render immune cells resistant to HIV. Image: Illustration by Owen Gildersleeve, Photograph by Sam Hofman
- HIV makes use of a particular protein called CCR5, which is found on the surface of some immune cells, to infect those cells.
- Some people have inherited a specific mutation that disables their copies of the CCR5 protein, thus offering them greater protection against infection with HIV.
- Investigators are trying gene-editing techniques to modify immune cells so that they lack the CCR5 protein, making them resistant to HIV as well.
- Preliminary results from safety studies of the gene-editing approach in humans are encouraging, but there is still a long way to go.
More In This Article
A little more than three years ago a medical team from Berlin published the results of a unique experiment that astonished HIV researchers. The German group had taken bone marrow—the source of the body’s immune cells—from an anonymous donor whose genetic inheritance made him or her naturally resistant to HIV. Then the researchers transplanted the cells into a man with leukemia who had been HIV-positive for more than 10 years. Although treatment of the patient’s leukemia was the rationale for the bone marrow transplant therapy, the group also hoped that the transplant would provide enough HIV-resistant cells to control the man’s infection. The therapy exceeded the team’s expectations. Instead of just decreasing the amount of HIV in the patient’s blood, the transplant wiped out all detectable traces of the virus from his body, including in multiple tissues where it could have lain dormant. The German researchers were so surprised by the spectacularly positive results that they waited nearly two years before publishing their data.
The news seemed too good to be true. And yet five years after undergoing his initial treatment, the so-called Berlin patient (who later disclosed his identity as Timothy Ray Brown of California) still shows no signs of harboring the AIDS virus—despite not taking HIV-fighting, antiretroviral drugs for all this time. Of the more than 60 million people who have been infected with HIV over the past few decades, Brown is so far the only individual who appears to have well-documented eradication of the infection.
This article was originally published with the title Blocking HIV's Attack.