I’m not sure how I have come off as arrogant. But, I’m fallible just like every other human, including Nobel Laureates. I’m curious to see whether they are actually citing plausible pathogenicity or food web disruption, or if it is just sensationalism from the authors or the science communicator.
Currently, pathogens “use” certain resources in a host, and then the host’s immune system creates antibodies that eventually kill the pathogens (or the pathogen kills the host).
This is a pretty good understanding. However, antibodies are only one tool in the immune systems of complex animals. There are also a number of specialized immune cells that perform jobs like patrolling the body to try to detect foreign cells and objects to “label” as invaders, or phagocytes that try to envelope and digest foreign cells and objects. Additionally, there are strategies like making the body a less hospitable environment by increasing the temperature (fever). Antimicrobial chemical production is also very common in single-celled organisms but identified in fewer complex animals.
My question is: mirror or otherwise, could a pathogen “hijack” something other than usual as a resource?
Let’s say, I don’t know, Prime Pathogen A normally uses Prime Protein A, Mirror Pathogen A would require Mirror Pathogen A. Is it possible for a host to have a Prime Protein B that meets Mirror Pathogen A’s requirement–perhaps not perfectly, but “good enough” to sustain Mirror Pathogen A?
Possible but, when looking specifically at the hypothetical “mirror” biology, less likely and probably would require specialized adaptations. The main problem that they would need to overcome, which is rather uncommon in known life is the mirrored shape of important biological molecules. Specifically, amino acids and sugars.
Both of these types molecules have a property known as “chirality”, where the atoms in the molecule can be oriented in two ways, while still all being bonded to the same neighbors. These are known as enantiomers and designated with the prefixes “levo” (“l-”), meaning left, and “dextro” (“d-”), meaning right. Biology as we know it is very specialized to make use of l-amino acids and d-sugars. There are some exceptions but they tend to be rather specialized and less energetically favorable.
Some organisms can break down d-amino acids and use their atoms as nitrogen sources to build new l-amino acids. It is much, much more common, however, to use l-amino acids from either the host cells or their proteins. This takes the pathogen far less energy to accomplish as well as not requiring evolving specialized enzymes that most organisms don’t have.
So, in the case of the mirror pathogen, it would have to have the ability and dedicate the energy to breakdown l-amino acids to build its d-amino acids. This would, indeed, likely result in slower growth rate. That, in itself, has a lot of potential to limit pathogenicity as high growth rate is generally required to be problematic. Phagocytes will still try to envelope and remove foreign objects that they don’t “think” are alive, so, the mirror pathogen could face risk of excretion if it is not able to reproduce quickly enough to maintain a population.
So, overall, yes, hypothetically possible and even plausible (if the mirror organisms are able to metabolize d-sugars and l-amino acids) but less likely. Pathogenicity requires the ability to grow a population fast enough or otherwise evade the immune system which is also able act on “invaders” that it does not recognize as biological (maybe being really good at building a bioplaque that makes it difficult to move or use of toxins). Simply having mirrored chemistry alone is probably insufficient to evade the immune system enough to be pathogenic.
Absolutely. Conversely, if mirrored microbes aren’t able to make use of building materials in hosts that are mirrors to them, pathogenicity makes little biological sense (microbes don’t make us sick out of spite). Now, if they could, that would be a problem. Even if not, they could fatally disrupt the gut microbiome.
The scope of what I suspect to be the greater danger, I’ve, perhaps understated. Suppose mirror bacteria “escape” and are able to thrive in the surrounding environment. As you note, known life has not evolved to be able to defend against it. This introduces the possibility of the artificial bacteria displacing the natural ones. Since the biosphere involves more complex organisms feeding on the smaller ones, it is plausible that the entire food web could be disrupted, leading to extinction of extant complex life, unless adaptation occurs quick enough.
ifwhen they read the 299-page report
Yup. Planning to crack that open this weekend :).
Unlike previous discussions of mirror life, we also realized that generalist heterotroph mirror bacteria might find a range of nutrients in animal hosts and the environment and thus would not be intrinsically biocontained
That is basically my suspicion, from my knowledge at this time. Pathogenicity as a danger seems questionable based upon how incompatible known life is with the opposite enantiomers of its basic building blocks (though, if artificial “mirror” bacteria were able to develop enzymes to change the chirality of the proteins, etc, it would probably be bad).
Going on that energy-intensive chemistry being tricky to accomplish, it is far more likely that generalists could displace extant microorganisms that may be unable to use their evolved defenses effectively. This could result in cascading food web disruptions until either extant life adapts, or complex organisms go extinct through starvation.
This is actually a fair and good question to ask. Being too credulous of things read on the Internet has shown rather problematic in recent years. Taking everything written in academic journals, especially opinion pieces not based upon peer-reviewed evidence, without skepticism has shown to be problematic since before the Internet, however.
Nobel Laureates have never made ridiculous statements that didn’t mesh well with scientific evidence. Kary Mullis, Nobel Laureate in Chemistry, credited with discovering PCR would never be quoted as refuting the evidence of HIV as causative in AIDS, cited in a journal article questioning the evidence, and then the journal article retracted due to it being inaccurately labeled as “Hypothesis and Theory” instead of opinion, factually inaccurate, and dangerous - oh. Oh no:
https://pmc.ncbi.nlm.nih.gov/articles/PMC6830318/
Next thing, you’ll tell me that scientists are humans that are fallible and some of them sometimes engage in ethically-questionable activities and sensationalism for profit.
Undergrad in biochemistry with a year research internship. Also, a long, AuADHD-fueled interest with chemistry, industrial microbiology, and reading research papers. Yourself?
This seems like something that really is a minimal risk. Pathogens are pathogens because they are able to make use of our bodies as raw materials to reproduce. Unless they are able to make use of both enantiomers in their biology, there’s little benefit to dedicating resources to colonizing us.
Probably a bigger concern would be outcompeting and displacing organisms lower on the food chain.
But don’t you see? Making the world an objectively worse place for everyone, especially marginalized people, and makes the harm to the biosphere more likely to be catastrophic and irreversible will totally load to it getting better. Everything works exactly like my maladaptive ADHD coping strategies from before my diagnosis and treatment - pushing things to the brim of annihilation will surely result in a better world and not just buckets of unnecessary human suffering and possible extinction.
/s
HFCS in everything.
I haven’t used Windows personally in about 15 years and professionally in about 10. I’m pretty useless on anything newer than XP. I even got my wife to switch over to a Mac Mini because at least that has a Unix-like OS and she can still do her audio work on it (in fact, better than a Windows system because their patch QA is light-years ahead of the MS “fuck it, it’ll break some systems but we’ll get that next patch Tuesday” approach).
That’s not to say that I like Apple. I just dislike their OS less than Windows.
Looks like we’re setting up an improvised KVM device! :D
I just tell them that I only deal with Linux and that is usually enough to dissuade.
…I don’t actually know what you mean, if you know what I mean.
And to maintain slavery. It’s really frustrating.
That might be minimum wage in two decades who knows
Living wage? Maybe-to-probably. Minimum wage? Doubtful.
That’s the only place it’s gone for a half-century.
In all fairness, I also agree with them likely being a solid source of information. There’s been a huge trend of leveraging academic credentials to boost sensationalism in recent years, so, until I read their reasoning, I am skeptical, specifically of whether or not it is blown out of proportion by the authors or the science communicator.