For the primary time, scientists have found how to efficiently and
precisely remove genes from white blood cells of the system and to insert beneficial
replacements, all in far less time than it normally takes to edit genes.
If the technique is often replicated in other labs, experts said,
it's going to open up profound new possibilities for treating an array of diseases, including
cancer, infections like H.I.V. and autoimmune conditions like lupus and atrophic arthritis.
The new work, published on Wednesday within the journal Nature,
“is a serious advance,” said Dr. John Wherry, director of the Institute of Immunology at The University of Pennsylvania, who wasn't involved in the study.
But because the technique is so new, no patients have yet been
treated with white blood cells engineered with it.
“The proof is going to be when this technology is employed to
develop a replacement therapeutic product,” cautioned Dr. Marcela Maus, director of cellular immunotherapy at
Massachusetts General Hospital.
That test might not be distant. The researchers have already used
the tactic within the laboratory to change the abnormal immune cells of youngsters with
a rare genetic condition.
They decide to return the altered cells to the youngsters in an
attempt to cure them.
Currently, scientists attempting to edit the genome often must
believe modified viruses to slice open DNA during a cell and to deliver new genes into the
cell.
The tactic is time-consuming and difficult, limiting its use.
Despite the drawbacks, the virus method has had some success.
Patients with a couple of rare blood cancers are often treated with engineered white blood cells
— the immune system’s T-cells — that go on to the tumors and kill them.
This type of treatment with engineered white cells, called
immunotherapy has been limited due to the problem of creating viruses to hold the genetic
material and therefore the time needed to make them.
But researchers now say they need a found how to use electrical
fields, not viruses, to deliver both gene-editing tools and new genetic material into the
cell.
By speeding the process, in theory, a treatment might be available to patients with
almost any sort of cancer.
“What takes months or maybe a year may now take a few weeks using
this new technology,” said Fred Ramsdell, vice chairman of research at the
Parker Institute for Cancer Immunotherapy in San Francisco.
“If you're a cancer
patient, weeks versus months could make an enormous difference.”
“I think it’s getting to be an enormous breakthrough,” he added.
The Parker Institute already is functioning with the authors of
the new paper, led by Dr. Alexander Marson, scientific director of biomedicine at the
Innovative Genomics Institute — a partnership between University of California, San Francisco
and therefore the University of California, Berkeley — to form engineered cells to treat a spread
of cancers.
In the new study, Dr. Marson and his colleagues engineered T-cells
to acknowledge human melanoma cells.
In mice carrying the human cancer cells, the
modified T-cells went right to cancer, attacking it.
The researchers also corrected — within the lab — the T-cells of
three children with a rare mutation that caused autoimmune diseases.
The plan now's to return
these corrected cells to the youngsters, where they ought to function normally
and suppress the defective immune cells, curing the youngsters.
The technique can also hold great promise for treating H.I.V., Dr.
Wherry said.
The H.I.V. virus infects T-cells. If they will be engineered in the order that the virus cannot enter the T-cells, an individual infected with H.I.V. shouldn't reach
AIDS. Those T-cells already infected would die, and therefore the engineered cells
would replace them.
Previous research has shown it'd be possible to treat H.I.V.
during this way. “But now there is a very efficient strategy to try to do this,” Dr. Wherry
said.
The idea of engineering T-cells without employing a virus isn't
new, but the immune cells are fragile and hard to stay alive within the lab, and it's always
been difficult to urge genes into them.
Scientists usually introduced replacement genes into T-cells with
a kind of virus that was disarmed in order that it might not cause disease which can insert
new genes into cells.
But when these viruses insert the genes into a cell’s DNA, they are
doing so haphazardly, sometimes destroying other genes.
“We needed something targeted, something fast and something
efficient,” Dr. Marson said.
“What if we could just paste during a piece of DNA and avoid
the viruses altogether?”
The idea would be to slide a kind of molecular scissors, referred
to as Crispr, into cells that would slice open DNA wherever scientists wanted a replacement gene
to travel.
That might avoid the problem of employing a virus that inserts genes just about
randomly.
And alongside the scissors, they might add a bit of DNA containing
the new gene to be added to the cells.
One way to try to that might be to use an electrical field to
form the cells permeable.
It required a herculean effort by a grad student, Theo Roth, to
finally, find out the right molecular mixture of genes, gene-editing tools and
electrical fields to switch T-cells without an epidemic.
“He tested thousands of conditions,” Dr. Marson said.
Already the scientists are lecturing the Food and Drug
Administration about using the new method to exactly attack solid tumors, also as blood cancers.
“Our intent is to undertake to use this as quickly as possible,”
Dr. Ramsdell said.
So once they knew that they had a system that worked, did they
escape the champagne?
Have a party?
Well, no, Mr. Roth said in an interview. He just took the info to
Dr. Marson.
“We certainly had an exuberant walk to Alex’s office,” he
recalled.
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