Page 12 - HOSPITAAL

A28 SCIENCE
Wednesday 14 February 2018
Can gene therapy be harnessed to fight the AIDS virus?

By MARILYNN MARCHIONE treatment,” he explained.
AP Chief Medical Writer The hope is that the medi-
For more than a decade, cines plus the altered cells
the strongest AIDS drugs will knock down the virus
could not fully control Matt and reduce the reservoir
Chappell's HIV infection. to a point where the body
Now his body controls it by can control any residual
itself, and researchers are disease by itself, as Chap-
trying to perfect the gene pell seems to be doing.
editing that made this pos- PROTECT AND ATTACK
sible. University of Pennsylvania
Scientists removed some scientists are trying a two-
of his blood cells, disabled part approach: Besides
a gene to help them resist knocking out the gene for
HIV, and returned these the HIV entryway, they’re
"edited" cells to him in 2014. adding a gene to help T
So far, it has given the San cells recognize and kill HIV.
Francisco man the next This second part is called
best thing to a cure. CAR-T therapy, a treat-
"I've been off medications ment approved last year
for three and a half years," for treating cancer.
he said. He even was able The new study’s leader,
to keep the virus in check scientist James Riley, is en-
despite cancer treatments couraged that some pa-
last year that taxed his im- tients at Penn who were in
mune system. the early studies kept HIV
Chappell was lucky, suppressed for nearly a
though. Only a few of the year without drugs.
100 others in those experi- In this Jan. 26, 2018 photo, Matt Chappell, left, talks with Dr. Christopher Schiessl during an ap- “You’d never know they
ments were able to stay pointment at a medical center in San Francisco. were sick” even though
off HIV drugs for a couple Associated Press the virus could still be de-
years; the rest still need tected, Riley said. “At some
medicines to keep HIV sup- who can't easily control the create similar immunity by Once a stem cell is altered point you’re going to have
pressed. virus, and should be pur- altering some of a patient's the benefit should multiply confidence that it’s not go-
Now researchers think they sued because it holds po- own cells. They use a gene and last longer, Zaia said. ing to come back.”
can improve the treat- tential for a cure. editing tool called zinc fin- THE SILVER LINING Chappell’s doctor, Christo-
ment and are trying again "They're very bold, innova- ger nucleases, which cut Though the initial gene ed- pher Schiessl at One Medi-
to tackle HIV by doctoring tive techniques, mostly to DNA at a precise spot to iting experiments were dis- cal, a health clinic in San
DNA. New studies to test try and cure people," he disable the HIV entryway appointing, there was a sil- Francisco, hopes that’s
these tweaked approach- said. "It's worth trying be- gene. ver lining. Patients in those the case for Chappell. Al-
es in people are getting cause the science is there." The California company studies had a big drop in though he’s doing well
underway. ONE MAN'S CURE GAVE that makes the editing tool, the number of cells where now, Chappell is showing
"Gene therapy techniques HOPE Sangamo Therapeutics, HIV lurked in a dormant signs that his immune sys-
have advanced greatly," Only one person is known sponsored the initial stud- state — the so-called reser- tem may be weakening,
said Dr. Otto Yang of the to have been cured of HIV ies. voir of silent disease. Schiessl said.
UCLA AIDS Institute, one infection, a man who had “It worked, the T cells were At Case Western Reserve Chappell is optimistic, and
place working on this. "A lot a cell transplant a decade edited,” said Sangamo’s University in Cleveland, Dr. believes gene therapy ulti-
of people are thinking it's ago from a donor with nat- president, Dr. Sandy Mac- Rafick-Pierre Sekaly is trying mately will provide a long-
the right time to go back." ural immunity to the virus. rae. But it didn’t work quite to capitalize on that drop. term solution.
They include Dr. Anthony The donor lacked a com- well enough: The altered T His study will try the same “If we’re going to cure
Fauci, director of the Na- mon gene that makes an cells were outnumbered by gene editing — disabling HIV,” he said, “this is how
tional Institute of Allergy entryway HIV uses to infect T cells that were not altered the gene that makes the it’s going to happen.”q
and Infectious Diseases, T cells, immune system sol- and could still be infected. HIV entryway — while
which is funding some of diers in the blood. Now, Dr. John Zaia at City keeping patients on strong
the new studies. He doesn't The transplant gave the re- of Hope, a research cen- antiviral medicines for at
think the technique will be- cipient that protection, but ter in Duarte, California, is least a year before discon-
come common because procedures like that are trying the approach with tinuing them.
millions of people do well too risky and impractical a twist. He’s using blood “As long as we’re not able
on existing treatments. But for wide use. Scientists have stem cells — parent cells to get rid of this reservoir,
he says it could help those been trying to find a way to that produce many others. we’ll never be able to stop