[HN Gopher] Scientists have discovered the first virovore - an o...
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       Scientists have discovered the first virovore - an organism that
       eats viruses
        
       Author : xiaodai
       Score  : 208 points
       Date   : 2023-01-03 12:57 UTC (10 hours ago)
        
 (HTM) web link (news.unl.edu)
 (TXT) w3m dump (news.unl.edu)
        
       | [deleted]
        
       | novia wrote:
       | Pretty sure we eat viruses all the time. Good to experimentally
       | demonstrate that they are able to provide a benefit though.
        
         | theandrewbailey wrote:
         | Indeed. Only a small handful of viruses infect humans. An XKCD
         | What-If was particularly enlightening for me: https://what-
         | if.xkcd.com/80/
        
         | divbzero wrote:
         | Yes, I suppose the more interesting finding is the ability to
         | grow on a virus-only diet.
        
       | fnordpiglet wrote:
       | I, for one, welcome our new vivore overlords.
        
         | [deleted]
        
         | shadowgovt wrote:
         | Virovoverlords?
        
       | [deleted]
        
       | water8 wrote:
       | [dead]
        
       | ethbr0 wrote:
       | Would be fascinated to hear _how_ the hell they do this
       | microbiologically. This study just seemed to strongly indicate
       | they do it.
       | 
       | I mean, as the consumER you'd have to (a) be resistant to getting
       | infected by the virus in the first place, (b) encapsulate the
       | virus in a way it can't broach, (c) deactivate and decompose it
       | into nutrients you can use, no?
       | 
       | Which seems a tall order for something designed and continually
       | evolving to breach your cell walls!
       | 
       | Granted, Halteria ciliates don't appear to be the virus' primary
       | target, so potentially lack necessary binding points / are
       | impenetrable to them, but that seems like playing with fire. Or
       | eating plankton if plankton were carnivorous and rapidly
       | evolving...
       | 
       | Although maybe it makes evolutionary sense if the Halteria:algae
       | ratio is extremely low? I.e. it was never beneficial to target
       | Halteria when more numerous food sources were colocated.
        
         | echelon wrote:
         | > lack necessary binding points
         | 
         | Viruses need far more than binding points to make use of a
         | cell. They need to handle attachment, penetration, uncoating,
         | gene expression, replication, assembly, and release. Some of
         | these may leverage host machinery, or sometimes the virus packs
         | their own. If they use the host, they typically need to have
         | greater flux kinetics than the host. If they're able to do
         | this, there's a chance they resemble a virus that the host
         | already knows how to deal with. In that case, they'll also need
         | to outmaneuver any existing intracellular defenses.
         | 
         | That's a lot of evolution that has to happen to fit your
         | target.
        
         | fnordpiglet wrote:
         | I think from the article the viruses don't target the ciliates
         | at all but rather algae. That explains (a). I expect b and c
         | are answerable with gradients and membrane mumbojumbo, but a
         | programmer not a microbiologist. I actually like the study
         | author am surprised that this hasn't been observed before. I
         | would have expected viruses are food for something - as it
         | notes they're little bundles of tasty proteins and useful
         | elements.
        
       | jjtheblunt wrote:
       | "virovore"...
       | 
       | latin years in school flashback, but that word is malformed,
       | because virus is Latin 4th declension and there's no -o stem in
       | any case. seems "viruvore" would be more appropriate, and matches
       | the forming of actual latin present active participle (think -ing
       | in english) "virulens" (virulent).
       | 
       | https://en.wiktionary.org/wiki/Appendix:Latin_fourth_declens...
       | 
       | Assuming "virus" is 2nd declension leads to a contradiction, in
       | there is an -o stem in a case, but that assumption contradicts
       | the centuries old "virulent" which wasn't written "virolent".
       | 
       | And the reason i mention all this is that i have no idea how one
       | finds modern etymologies for classical words without knowing the
       | languages (or subsets of course) outright.
        
         | msla wrote:
         | If you're doing that, the Latin word "virus" means slime, so we
         | should treat the English word as something entirely different.
        
           | jjtheblunt wrote:
           | I guess Greek "contagion" closer matches what English refers
           | to with "virus" and it's repurposed meaning?
        
             | jjtheblunt wrote:
             | "contagion" while Greek in ending looks like con-
             | (together) and a Greek analogue of "tango, tangere, ... ,
             | tactus" (touch). Like whatever happens with two things
             | touching?
        
           | atkailash wrote:
           | [dead]
        
         | Existenceblinks wrote:
         | Cool name candidates for security people to use for their
         | software.
        
           | jjtheblunt wrote:
           | Viruvore Antivirus LLC ? :)
        
         | [deleted]
        
       | weatherlight wrote:
       | I just learned about virophages a few days ago. Viruses and their
       | relationship to other organisms or viruses is bizarre.
       | 
       | https://en.wikipedia.org/wiki/Virophage
       | 
       | I wonder if virovores could be exploited for medical purposes?
        
         | maxbond wrote:
         | Seems like it'd be super useful for maintaining a virus-free
         | environment in an ongoing manner in a circumstance where they
         | would contaminate your results, but where the virovores
         | wouldn't. Maybe there's a virus that you're able to account for
         | in your methodology that you feed the virovores with, and they
         | stick around and clean up other viruses that get into your
         | culture.
         | 
         | Or maybe in an industrial process they could help dampen the
         | spread of viral outbreaks in your bioreactor.
        
           | anonymouskimmer wrote:
           | Co-culture might be fine. But realistically it's probably a
           | lot easier to add neutralizing antibodies or other peptides
           | or chemicals which would block viral infection.
           | 
           | For an industrial process it would likely be easier to just
           | genetically modify your organism to be resistant to the
           | virus.
        
             | maxbond wrote:
             | A nice benefit of the virovore though would be it would
             | evolve to counter evolution of the virii. You could still
             | treat with peptides &c but eventually they'll stop being
             | effective. Against a highly adaptive organism it's probably
             | best to employ multiple overlapping treatments. I'm not
             | 100% sure it's this particular talk [1], but this
             | researcher has a fascinating talk on this channel about
             | using phage therapy in tandem with antibiotics such that
             | bacteria resistant to the antibiotic are susceptible to the
             | phage. Iirc they were able to clear up a life threatening
             | antibiotic resistant infection in a patient's aorta with a
             | single treatment.
             | 
             | Genetic modification can be tricky in long-lived cultures,
             | the organism you're cultivating may discard your
             | modifications. There's things you can do to make this more
             | difficult, but I can imagine a really general solution that
             | works for many cultures could be super useful (say, for
             | cultures you're speculating about productizing, but don't
             | want to make too much of an investment in until you've
             | characterized them better).
             | 
             | I ran some wild west style, open air algae bioreactors for
             | a while, and I'd fantasize about productizing organisms
             | like this for pest control. Crazy things can happen in that
             | sort of environment; I wasn't around at the time but there
             | was a story about a storm which blew in from the against
             | prevailing winds, carrying some weird kind of rotifer not
             | normally native to that environment, and across the state
             | people woke up to their ponds turning pink. In that kind of
             | environment you're unable to anticipate which organisms
             | will invade your ponds. I think it's possible those kinds
             | of cheap, low-control methods of production will become
             | very important.
             | 
             | [1] https://youtu.be/xvC8xME5Zrg
        
               | anonymouskimmer wrote:
               | I've known about phage therapy for a while. That's quite
               | interesting in your last paragraph.
        
         | logicalmonster wrote:
         | There was a 1st Season Episode of Star Trek Voyager called The
         | Phage where a bunch of aliens whose organs were being eaten
         | away by some virus had to continuously harvest fresh new organs
         | from unwitting travelers to stay alive. Is that fictional
         | disease related to the real world virophage?
        
           | QuercusMax wrote:
           | Phage just means "something that devours".
           | https://www.dictionary.com/browse/phage
           | 
           | As far as I can tell, the Phage that the Vidiians suffer from
           | has nothing to do with any real-world illnesses, except maybe
           | something like Leprosy.
        
             | logicalmonster wrote:
             | In Greek, the word Phage or Fage means "to eat" so that
             | might be the origin. Coincidentally, that's also the name
             | of a pretty rich and thick yogurt, which I assume has
             | nothing to do with viruses.
        
               | [deleted]
        
       | gz5 wrote:
       | Fascinating. It seems sensible (to a layman) that something would
       | eat viruses but how would we construct tests (not trolling) to
       | determine:
       | 
       | 1. if the Halteria were not eating something_else, and that
       | something_else was infected by the viruses?
       | 
       | 2. if the Halteria themselves were not infected by the viruses?
       | 
       | 3. are the Halteria trying to ingest the viruses, or are they
       | just ingesting lots_of_things in the petri dish?
       | 
       | This observation seems interesting, assuming all other variables
       | were constant and there was not some other interplay between the
       | chlorovirus and other microbes which indirectly helped the
       | Halteria grow:
       | 
       | >Halteria deprived of the chlorovirus, meanwhile, wasn't growing
       | at all.
       | 
       | Finally if the Halteria can ingest it and yet not be 'infected'
       | by it then that seems awfully interesting as well.
        
         | fnordpiglet wrote:
         | Viruses as I understand it are generally fairly specific as to
         | what they can infect. I don't think there's any reason to
         | believe an algae virus infect ciliates. But again, I'm a
         | programmer, not a microbiologist.
        
           | zdragnar wrote:
           | Cross-species infection usually happens (I _think_ ) due to
           | mutation, rather than a single strain being able to target
           | vastly different species.
           | 
           | However, there are some that do. For example, the Powassan
           | virus. Ticks pick up the virus from woodland mammals, and
           | then transfer it to humans. However, ticks do not transfer
           | the disease from human to human [0].
           | 
           | https://en.m.wikipedia.org/wiki/Powassan_virus
           | 
           | We are probably much closer to mice and squirrels than algae
           | are to ciliates though.
        
         | stultissimus wrote:
         | Biophysicist here. Excellent questions - these are the kind of
         | points peer reviewers would raise (though typically in far more
         | esoteric and passive aggressive ways...).
         | 
         | (1) could be addressed in experiments where the algae-consumers
         | in question are studied in monoculture (purified and grown in
         | test tubes) with virus added artificially. This experimental
         | design excludes the possibility that any middle man is present;
         | if uptake is still observed, it must be direct.
         | 
         | (2) Measure viral replication, perhaps in a similar monoculture
         | experiment as above. If the viruses are infecting (exploiting)
         | the Halteria, they will have non-negligible replication (they
         | are stealing the Halteria's resources to advance their own
         | replication). Viral replication could be assayed by qPCR
         | (counting viral genomes) or similar assays.
         | 
         | (3) This would require biochemical studies to determine the
         | mechanism of uptake of viral particles. Typically, viruses are
         | taken up (endocytosed) by cells as a result of interaction with
         | receptors on the surface of target cells (prominently CCR5 in
         | HIV, Ace2 for the COVID-19 causing virus). Of course, what
         | biological systems are `trying` to do begs that we
         | anthromorphize Halteria (or at least evolution), but one could
         | conduct an evolutionary analysis to see if Halteria have
         | progressively evolved receptors that improve viral uptake
         | efficiency.
         | 
         | As an aside, the discovery of virovores hints excitingly
         | (albeit remotely) at the possibility of creating virus sink
         | cells/technologies that could eliminate viral particles in
         | humans. An important question will be whether viruses, which
         | evolve far faster than eukaryotes like Halderia (let alone than
         | humans), can turn the tides in the evolutionary arms race and
         | become the exploiters of the Halderia. Perhaps it's reassuring
         | that we exist (mostly) symbiotically with our microbiota,
         | despite their far faster evolution.
        
           | hanniabu wrote:
           | > An important question will be whether viruses, which evolve
           | far faster than eukaryotes like Halderia (let alone than
           | humans), can turn the tides in the evolutionary arms race and
           | become the exploiters of the Halderia.
           | 
           | I'd assume that's the case, otherwise I feel like there would
           | be more Halderia and/or less viruses
        
           | panabee wrote:
           | great answers to great questions.
           | 
           | 1. the parent raised questions in a neutral way. these
           | questions seem essential for validating experimental design.
           | why would peer reviewers present such questions in passive-
           | aggressive ways, and how can we fix this?
           | 
           | 2. could you kindly recommend services/consultancies to
           | validate experimental designs? if not, would you be open to
           | consulting and doing what you did here -- suggesting ways to
           | control for key variables? experiments relate to cancer
           | research. contact info in bio.
        
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       (page generated 2023-01-03 23:00 UTC)