Scientists use optogenetics to help a blind patient see again | Hacker News Reader

Scientists use optogenetics to help a blind patient see again

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199 pointsbmau514 comments

This “first” is one in a family of firsts. There have been other in vivo genetic treatments for RP (and perhaps other eye related genetic conditions)

This one involves inserting a nonhuman gene into existing cells to turn them into a kind of hacked photoreceptor.

Another method involves crispr editing in place fixing the mutation to its non diseased human equivalent (apparently not possible in the article related type of RP which causes cell death, can’t fix what isn’t there)

A third kind involves generating a stem cell line of the patient, using crispr to fix the faulty gene, growing, and then implanting fixed retinal cells into the patient.

I believe all three have now had “firsts” in human trials.

The article in question seems interesting, but the less exciting of the three.

We've de-firsted the title above. Actually that's pretty much always a good move in titles. If something is interesting, it's probably interesting even if it isn't the first, and most claims to firstiness tend to have distracting effects on threads.

Says one author of publication: “It’s a major milestone,” said study leader and ophthalmologist José-Alain Sahel of the University of Pittsburgh and the Sorbonne University in France.

Says unaffiliated doctor: “It’s a small step forward but it is a definite step forward in that they’ve been able to prove that this does work in humans,” said Paul Bernstein, an ophthalmologist and retinal specialist at the University of Utah School of Medicine, who was not involved in the study.

It's neat to see optogenetics (and genetic manipulations in general) being applied to humans. The journey from research to real-world application is effing long.

Really curious about the pacient's take too

Yes, it'd be interesting to see the patient's view on this

At least the patient has a view, however dim.

> When the black goggles he was wearing projected video images of his surroundings as a pulsed light beam onto those now-light-sensitive cells, the neurons fired, and the signal traveled up the optic nerve and into the visual processing center of the brain. The genetically modified neurons had become stand-ins for the photoreceptors he had lost many years before to a genetic disease called retinitis pigmentosa.

Sounds like the visor Geordi La Forge is wearing. Star Trek predicted cellphones, tablets and now this. Hopefully teleportation is next.

Your clone that emerged from the teleporter would never know that you died screaming in agony as you were disassembled.

Is there a problem?

More interestingly, Star Trek had one episode and then some recurring references covering the idea that you can clone someone in a transporter without dissolving the original copy. You would expect a large number of people to want to do this, but it just never comes up.

Anyone familiar with this know what the immune response/impact was due to this treatment?

I have read papers for similar genetic engineering in eyes. They infect the eye (or specific retina areas) with a virus, there is local inflammation while the immune system does its job with some mild side effects for a few weeks at most.

After the viral infection i never saw any mention of immune rejection or other reaction to the modified tissues.

From my limited understanding, in order to have an immune response there has to be something different for the immune system to “see” usually on the surface of cells... expressing a protein inside apparently doesnt raise to that level.

Caveat: I did not read the paper but can weigh in on this:

1. The eye has immune privilege, similar to that of the brain, meaning it can tolerate antigens that would normally trigger an immune response elsewhere, like your arm.

2. Fragments of proteins expressed internally are normally presented on the surface of cells through a process called antigen-presentation. This allows immune cells to "see" when cells are infected and expressing proteins in the cytosol they normally would not.

Together this means that exogenous expression of proteins in the eye do not trigger inflammation because the eye is immune privileged, but if those proteins were expressed in the arm, there would be an immune response even if proteins are only cytosolic.

>1. The eye has immune privilege, similar to that of the brain, meaning it can tolerate antigens that would normally trigger an immune response elsewhere, like your arm.

This is my theory, too. I worked on optogenetics in the periphery and the immune response is catastrophic, often leading to loss-of-function worse than a pre-existing condition or trauma. The way we got around this was with immune response suppressants like Tacrolimus. [0]

But my expertise dramatically drops off with CNS immunity, not to mention the eyes which I know very little about.

[0] https://www.nature.com/articles/s41598-018-32075-0

decades of effort have gone into making this type of treatment safe, but mistakes or lack of understanding have resulted in patients’ death and set the field back before, see for example: https://en.m.wikipedia.org/wiki/Jesse_Gelsinger

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