https://www.wired.com/story/chinese-scientist...th-crispr/
Imagine you’re 27 years old and you start feeling ill. Ill enough that you go to the hospital, and after much poking and prodding and waiting for lab results you learn you’re HIV positive. Two weeks later you find out that’s not even the worst of it. You’ve got leukemia too.
Under any circumstances it would be a lot to take in. Especially in China, where HIV/AIDS is highly stigmatized. But for one young man living there, who this happened to in the late spring of 2016, there was one small but significant silver lining to this double whammy of a diagnosis. He would be eligible to participate in the first-ever clinical trial to assess the safety of trying to cure both the cancer and the infection in a single procedure using the gene-editing tool called Crispr.
In July of 2017, doctors in Beijing blasted the patient with chemicals and radiation to wipe out his bone marrow, making space for millions of stem cells they then pumped into his body through an IV. These new stem cells, donated by a healthy fellow countryman, would replace the patient’s unhealthy ones, hopefully resolving his cancer. But unlike any other routine bone marrow transplant, this time researchers edited those stem cells with Crispr to cripple a gene called CCR5, without which HIV can’t infiltrate immune cells.
Now, more than two years later, the patient is in good health, his cancer in full remission, as researchers report today in the New England Journal of Medicine. The edited stem cells survived and are still keeping his body supplied with all the necessary blood and immune cells, and a small percentage of them continue to carry the protective CCR5 mutation. Not enough to have cured him of HIV, though—he remains infected and on antiretroviral drugs to keep the virus in check. Still, experts say the new case study shows this use of Crispr appears to be safe in humans and moves the field one step closer toward creating drug-free HIV treatments.
....
In an ideal world, both copies of the CCR5 gene would get snipped in all of the 163 million or so stem cells they isolated from the donor’s bone marrow. That would replicate what the Berlin Patient received from his donor. What the researchers got instead was much lower. After transplantation, only between 5.2 and 8.3 percent of the patient’s bone marrow cells carried at least one copy of the CCR5 edit. (The study authors didn’t report how many cells had both copies versus one copy edited.)
That number stayed more or less stable over the 19 months that researchers have so far tracked the patient. But the more telling question is whether T cells in the patient’s blood also retain the edit. In the specific kind of T cells that HIV uses to infiltrate the immune system, the broken version of CCR5 was present in only about 2 percent of them
Imagine you’re 27 years old and you start feeling ill. Ill enough that you go to the hospital, and after much poking and prodding and waiting for lab results you learn you’re HIV positive. Two weeks later you find out that’s not even the worst of it. You’ve got leukemia too.
Under any circumstances it would be a lot to take in. Especially in China, where HIV/AIDS is highly stigmatized. But for one young man living there, who this happened to in the late spring of 2016, there was one small but significant silver lining to this double whammy of a diagnosis. He would be eligible to participate in the first-ever clinical trial to assess the safety of trying to cure both the cancer and the infection in a single procedure using the gene-editing tool called Crispr.
In July of 2017, doctors in Beijing blasted the patient with chemicals and radiation to wipe out his bone marrow, making space for millions of stem cells they then pumped into his body through an IV. These new stem cells, donated by a healthy fellow countryman, would replace the patient’s unhealthy ones, hopefully resolving his cancer. But unlike any other routine bone marrow transplant, this time researchers edited those stem cells with Crispr to cripple a gene called CCR5, without which HIV can’t infiltrate immune cells.
Now, more than two years later, the patient is in good health, his cancer in full remission, as researchers report today in the New England Journal of Medicine. The edited stem cells survived and are still keeping his body supplied with all the necessary blood and immune cells, and a small percentage of them continue to carry the protective CCR5 mutation. Not enough to have cured him of HIV, though—he remains infected and on antiretroviral drugs to keep the virus in check. Still, experts say the new case study shows this use of Crispr appears to be safe in humans and moves the field one step closer toward creating drug-free HIV treatments.
....
In an ideal world, both copies of the CCR5 gene would get snipped in all of the 163 million or so stem cells they isolated from the donor’s bone marrow. That would replicate what the Berlin Patient received from his donor. What the researchers got instead was much lower. After transplantation, only between 5.2 and 8.3 percent of the patient’s bone marrow cells carried at least one copy of the CCR5 edit. (The study authors didn’t report how many cells had both copies versus one copy edited.)
That number stayed more or less stable over the 19 months that researchers have so far tracked the patient. But the more telling question is whether T cells in the patient’s blood also retain the edit. In the specific kind of T cells that HIV uses to infiltrate the immune system, the broken version of CCR5 was present in only about 2 percent of them
1
