The claim that mirror molecules would not be subject to immune surveillance makes no sense to me. The immune system is happy to react to non-biological molecules. It reacts to shapes, not chirality. It is a separate question whether the immune response could break into mirror membranes and break down mirror molecules.
Mirror bacteria research poses significant risks, scientists warn
111–120 of 253 posts
Re: Mirror bacteria research poses significant risks, scientists warn
#112Earlier quoted context omitted.
Do we really "accept" microplastics? It seems to me most scientists in the field are terrified of microplastics, while simultaneously acknowledging it's a problem that we almost assuredly can't realistically solve on any reasonable timescale. I'm confident if we had seen microplastics coming when we first started using plastics, science at least would have tried to prevent their use becoming as widespread as it has.
Humanity knew very well that lead and mercury were highly toxic and yet only recently are they being phased out in widespread use. The Man Who Accidentally Killed The Most People In History https://www.youtube.com/watch?v=9sm1qxqdRyY Hundreds of millions of pounds of Glyphosate is spread across the entire globe. Scientists don't have much say in these things.
Humans only respond to acute threats. As a society we don’t have a means of effectively responding to long-term threats. We seem to only care about the next 5-10 years. Our species is short sighted, but I suppose evolution will correct that, eventually.
Re: Mirror bacteria research poses significant risks, scientists warn
#113The claim that mirror molecules would not be subject to immune surveillance makes no sense to me. The immune system is happy to react to non-biological molecules. It reacts to shapes, not chirality. It is a separate question whether the immune response could break into mirror membranes and break down mirror molecules.
Are you certain? The immune system detects molecules partly due to their shape, i.e. where binding points are on the proteins. I can imagine it being the case where the immune system's proteins no longer match up with the invader's because of the mirroring.
If you 3d print a mirrored house key, the bitting may line up with the original, but the warding wouldn't fit anymore. I think that's a reasonable analogy to the way proteins match up.
Re: Mirror bacteria research poses significant risks, scientists warn
#114Doesn't sound very scary on the face of it. Apparently [0] the problem with Thalidomide was that the chirality could spontaneously reverse, so that sort of thing must happen frequently in nature. If bacteria haven't figured out how to use mirroring under evolutionary pressure it probably doesn't actually have any advantages over following the herd. [0] https://en.wikipedia.org/wiki/Homochirality#In_biology
There are all kinds of examples of where the isomers of common compounds are bad for you, i.e. https://www.sciencealert.com/some-drugs-have-mirror-image-ch...
Re: Mirror bacteria research poses significant risks, scientists warn
#115The claim that mirror molecules would not be subject to immune surveillance makes no sense to me. The immune system is happy to react to non-biological molecules. It reacts to shapes, not chirality. It is a separate question whether the immune response could break into mirror membranes and break down mirror molecules.
The pMHC-TCR complex, which is the cornerstone of the adaptive immune system, has evolved to bind peptide epitopes.
Most D-amino acids are known to bind MHC poorly and lead to reduced TCR recognition. I imagine this could increase the chances of evading immune surveillance.
Re: Mirror bacteria research poses significant risks, scientists warn
#116Earlier quoted context omitted.
I’m sure it would attack it, and it likely would even succeed. The problem is the chiral molecules would be difficult to clean up. You’d have this anti-life bacteria torn to pieces, yes, but then the pieces get stuck everywhere and potentially jam things. Personally—not a biologist—it doesn’t feel like a huge risk, given we accept threats such as microplastics which do much the same thing. However, it’s a completely…
Do we really "accept" microplastics? It seems to me most scientists in the field are terrified of microplastics, while simultaneously acknowledging it's a problem that we almost assuredly can't realistically solve on any reasonable timescale. I'm confident if we had seen microplastics coming when we first started using plastics, science at least would have tried to prevent their use becoming as widespread as it has.
> It seems to me most scientists in the field are terrified of microplastics
Got anything you can point to? I haven't looked for a while but last time I did the evidence of harm appeared quite minimal. I recall that it was quite toxic in aquatic environments that had already been contaminated with (previously mostly harmless) low levels of heavy metals.
PTFE is similar in that it too hangs around in the environment for ages which is certainly a cause for concern. Yet it seems to be difficult to track down any known concrete negative effects. (If you are aware of any I would be interested in learning about them.)
Re: Mirror bacteria research poses significant risks, scientists warn
#117Earlier quoted context omitted.
Humanity knew very well that lead and mercury were highly toxic and yet only recently are they being phased out in widespread use. The Man Who Accidentally Killed The Most People In History https://www.youtube.com/watch?v=9sm1qxqdRyY Hundreds of millions of pounds of Glyphosate is spread across the entire globe. Scientists don't have much say in these things.
Humans only respond to acute threats. As a society we don’t have a means of effectively responding to long-term threats. We seem to only care about the next 5-10 years. Our species is short sighted, but I suppose evolution will correct that, eventually.
Well the average remaining life expectancy of all adult humans currently alive is probably only a little more than 10 years so it makes sense.
Re: Mirror bacteria research poses significant risks, scientists warn
#118Doesn't sound very scary on the face of it. Apparently [0] the problem with Thalidomide was that the chirality could spontaneously reverse, so that sort of thing must happen frequently in nature. If bacteria haven't figured out how to use mirroring under evolutionary pressure it probably doesn't actually have any advantages over following the herd. [0] https://en.wikipedia.org/wiki/Homochirality#In_biology
My go-to with any 'thing x could wipe out everything or is better than everything' is exactly this. If nature hasn't found it then I don't worry as much. That doesn't mean this shouldn't be considered and studied carefully, but this sounds like a bit more fear than it likely deserves.
Re: Mirror bacteria research poses significant risks, scientists warn
#119Searching HN for "mirror cells", I see at least 1 article warning of the dangers from more than 10 years ago. So, this has been a thing for a while. Any biologists here that can chime in on just how big of a risk they do pose? Is there a general consensus throughout the community that this research should end? Is this something that could be developed for bio-terrorism? Should work be started on developing mirror imm…
A completely "mirrored" organism is not that dangerous. - It would still have antigenic properties, just not the ones we are familiar with, because antigens are proteins or proteins bound to sugars. Both have "left" vs "right" variants. - It can't eat any ordinary food, except simple fats. Common proteins and sugars won't fit it's enzymes. That means it can't digest sugars, proteins or any combination that contains t…
So much confidence about how this thing we’ve never encountered will not be a problem.
Re: Mirror bacteria research poses significant risks, scientists warn
#120Doesn't sound very scary on the face of it. Apparently [0] the problem with Thalidomide was that the chirality could spontaneously reverse, so that sort of thing must happen frequently in nature. If bacteria haven't figured out how to use mirroring under evolutionary pressure it probably doesn't actually have any advantages over following the herd. [0] https://en.wikipedia.org/wiki/Homochirality#In_biology
I think the ostensibly scary subject here is mirror DNA or RNA, not anything-that-doesn't-self-replicate.
> If bacteria haven't figured out how to use mirroring
It's unclear bacteria have ever "attempted" it. The synthesis of DNA is incredibly intricate and complex, and the set of proteins that do it are believed only to have ever evolved once. In order for a bacteria to have "attempted" this, it would have to evolve an entirely new set of proteins from scratch.
Personally I think a self-replicating photosynthetic cell with mirror DNA is as scary as self-replicating photosynthetic plastic.