A Bold Effort to Cure HIV—Using Crispr

Patients will be spared from serious side effects or off-target edits if this strategy is adopted.

The parts of the genome that are targeted by Crispr therapy tend to stay the same when HIV arises. The researchers don't want a moving target, so that's important

This isn't the first time scientists have tried to use gene editing in the hope of curing people with HIV. Scientists discovered in the 1990s that people with this naturally occurring variation didn't get HIV when they were exposed to it. The virus can't get inside immune cells because of the Delta 32. An important part of the immune system, T cells are an important part of the genome. The trials have not had a lot of success.

The Chinese scientists combined Crispr with a bone marrow transplant to try and cure a patient with HIV and leukemia. Stem cells are used in a transplant to replace blood cells that have been removed. New healthy blood cells are formed by these cells. The stem cells were edited with Crispr to stop the HIV. A small amount of the patient's bone marrow cells ended up with the desired edit after the transplant.

The Chinese scientist used Crispr to modify the twins' genomes to make them resistant to HIV. The experiment was condemned by scientists. He was sentenced to three years in prison for his research being suspended. The twins may not be immune to HIV because some of their cells were edited.

Two people have been cured of HIV after getting bone marrow transplants. Both the Berlin and London patients had cancer and received transplants to treat it. These transplants are not a viable option for most people because of their high risk and scarcity of donors. A third person has been cured of HIV after receiving a cord blood transplant.

The trial will enroll nine people and test three different dosages. Before receiving the therapy, investigators will measure each person's viral load and CD4 count. The goal is to get the viral loads down to an undetectable level. It is not possible to pass on HIV through sex.

Getting Crispr to enough cells will be a challenge for Excision. The company is using an engineered virus to treat patients with HIV. There isn't a lot of data on how well Crispr works when it's delivered to the body. If a person's immune system is intact, they can keep the virus at bay and not have to take antiretroviral therapy.

Even though the drugs are effective, many people would rather not have the disease. If Crispr works, daily pills would be eliminated. She says that people with HIV live with a lot of shame. Regardless of how easy therapy becomes, a cure is better than lifelong therapy.