CRISPR-Cas9 now cheaper and can edit human T-cells

28 Jul 2015

The CRISPR-Cas9 genome editing system. Cas9 can cut target DNA at a site complementary to its loaded RNA. Purple cartoon protein model, RNA in cyan, target DNA magenta

The revolutionary DNA sequencing technique CRISPR-Cas9 is about to get a whole lot cheaper. Better still, it can now successfully edit the human T-cells.

Discovered a few years ago, the CRISPR-Cas9 technique has proved remarkably popular in the genomics field.

So much so that it has dipped into popular culture, becoming the premise behind Radiolabs’ June podcast – it was here, thanks to some wonderful dumbing down, that I became aware of just what CRISPR meant.

At their core, CRISPRs (clustered regularly interspaced short palindromic repeats) are DNA segments that contain repetitive sequences.

CRISPR-Cas9 is a technique that allows geneticists to home in on specific DNA sequences, slice out genes and edit them, before returning them into their original sequence.

Accuracy and science

This means the targeting of gene therapy can be more accurate, which could, someday, help discover and cure genetic diseases.

Not just that, though, as it can be used to simply monitor, highlighting DNA pieces with fluorescent colours to follow their every move.

It might sound a bit technical, well it is a bit technical, but it has been revolutionising genetics for a few years now.

Acronyms and savings

Of course, for a revolution to take hold there needs an explosion of access. And now, it seems, there can be.

According to UC Berkeley, a new technique can now make it possible to target DNA for less than US$100 worth of supplies, with which you can actually “make tens of thousands of such precisely-guided probes covering an organism’s entire genome”.

Because acronyms are always fun, this technique is called CRISPR-EATING (everything available turned into new guides), and details of it will be in an August 10 issue of Developmental Cell.

“We can make these libraries for a lot less money, which makes genetic screening potentially accessible in organisms less well studied”, such as those that have not yet had their genomes sequenced, said first author Andrew Lane, a UC Berkeley post-doctoral fellow.

This, coupled with a new human T-cell project, is big news

T-cells, cut and paste

Researchers at UC San Francisco successfully worked out a way to modify human T-cells – which play a key role in diseases like diabetes, AIDS and cancer – using CRISPR-Cas9.

According to one of the authors of the new paper, this process will allow us to edit T-cells with extreme precision thanks to a “cut and paste” process.

“Genome editing in human T-cells has been a notable challenge for the field,” said Alexander Marson, PhD, a UCSF Sandler Fellow, and senior and co-corresponding author of the new study.

“So we spent the past year-and-a-half trying to optimise editing in functional T-cells. There are a lot of potential therapeutic applications, and we want to make sure we’re driving this as hard as we can.

“We wanted not only to cut the genome, but to paste in sequences of DNA into the genome of T-cells. We have now been able to cut as well as paste pieces of the genome into human T-cells – for the first time to our knowledge,” he said.

If you’re still confused, here’s Radiolab to explain what CRISPR is all about:

Main image via Shutterstock

Gordon Hunt was a journalist with Silicon Republic