[divbzero]

> The trouble with mirror cells is that they could probably evade most of the barriers that keep ordinary organisms in check. To fight off pathogens, for example, our bodies must first detect them with molecular sensors.

> Those sensors can only latch onto left-handed proteins or right-handed DNA and RNA. A mirror cell that infected lab workers might spread through their bodies without triggering any resistance from their immune systems.

It’s clear that RNA wouldn’t be complementary to mirror RNA, but antibody binding is more complex than RNA hybridization. Is it a foregone conclusion that antibodies couldn’t bind to mirror antigens?

(Degrading mirror proteins, as mentioned elsewhere in OP, does seem like a bigger obstacle.)

[dekhn]

Antibodies can bind to wrong-handed antigens, but an antibody to a correct-handed antigen would not automatically bind the mirror. I'm not finding a lot of literaturee about this, however.

[andrewflnr]

> an antibody to a correct-handed antigen would not automatically bind the mirror

I wouldn't expect it to, but rather I'd expect the immune system to learn the new antigen just like it learned the old one.

[baranul]

Unfortunately, seems the only way to figure this out is by testing. But on the flip, nobody can really trust that it won't accidentally or purposefully escape from labs.

[gus_massa]

They can create a few mirrored proteins and sugars and test them. Without RNA (and a lot of additional machinery) the proteins and sugars will not start to spontaneusly reproduce to conquer the word.

[j16sdiz]

A prion don't have RNA, and yet they can reproduce

[gus_massa]

They can "reproduce" only in very specific environmens where there are similar non-malformed proteins nearby. It would be very hard to have a similar problem with a mirrored molecule that picks one type of normal molecules and mirror them.

[ashoeafoot]

Thus we can conclude military will make them. And they will escape.

[andrewflnr]

We really can't. Militaries in particular aren't into bioweapons. Too hard to aim. They're pretty much strictly the domain of terrorists, and terrorists don't have the resources to execute attacks on the bleeding edge of biotech.

Remember, no one has built a regular cell from scratch, much less come close to building a mirror cell.

[blincoln]

Military labs do work with bioweapons, and (unsurprisingly) they sometimes have trouble containing them just like regular labs.

E.g.

https://en.wikipedia.org/wiki/1971_Aral_smallpox_incident

https://www.fredericknewspost.com/archives/what-went-wrong/a...

https://www.nytimes.com/2004/05/25/world/russian-scientist-d...

https://www.usatoday.com/story/news/nation/2015/07/23/army-a...

[doctoboggan]

Wouldn't the bacteria be similarly disadvantaged when trying to sense its environment, eat, and reproduce in a completely mirror world?

[anon84873628]

From the article:

>The downside of having a biology that renders mirror bacteria ‘invisible’ to natural enemies is that they would not be able to consume many of the chiral nutrients found in nature. However, several nutrients, such as glycerol, are achiral (they do not have mirrored forms), and thus could be consumed by mirror bacteria. Well-intentioned scientists could also engineer mirror bacteria that can consume naturally occurring chiral molecules such as sugars and amino acids.