[HN Gopher] A physical wiring diagram for the human immune system
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       A physical wiring diagram for the human immune system
        
       Author : bookofjoe
       Score  : 304 points
       Date   : 2022-08-08 02:07 UTC (20 hours ago)
        
 (HTM) web link (www.nature.com)
 (TXT) w3m dump (www.nature.com)
        
       | hungryforcodes wrote:
       | This is a REALLY great paper. I'm assuming if you took the time
       | to look up and learn deeply about all the stuff you didn't know
       | that you read -- you'd be extremely knowledgable about the human
       | immune system after. It's like reading a very complex book. Take
       | a few weeks or months to really understand and absorb it all.
        
         | fiftyfifty wrote:
         | Someone else in another thread on here recommended the book
         | "Wetware: A Computer in Every Living Cell" by Dennis Bray and I
         | really enjoyed it. The idea of looking at complex protein
         | interactions as logical circuits kind of makes sense as we try
         | to map out the complexities of Biochemistry. For anyone looking
         | for an easier introduction to the concept I can recommend the
         | book.
        
       | beckerdo wrote:
       | I am reading "Immune: A Journey into the Mysterious System That
       | Keeps You Alive" by Philipp Detmer (https://www.amazon.com/gp/pro
       | duct/B08XTNHRR5/ref=ppx_yo_dt_b...). It is a great book for the
       | layman, and explains a number of processes in simple and lively
       | analogies. My understanding of the immune system increased
       | greatly.
       | 
       | However this paper of all the interactions is at a higher level.
       | I could just barely relate it to what I know. As an engineer I
       | appreciate the presentation of the data and the amount of thought
       | that went into it. I will have to study the paper more.
        
         | Hedepig wrote:
         | I purchased the audiobook, great listen
        
       | flobosg wrote:
       | In case you missed it, here's the interactive atlas:
       | https://www.sanger.ac.uk/tool/immune-interaction/immune-inte...
        
         | vavooom wrote:
         | Great use of a Shiny visualization here - wonderful way to
         | communicate these results
        
           | wiz21c wrote:
           | Dunno, tried it. It's painfully slow and the charts labels
           | are all crammed, it's unreadable. And I didn't see any
           | obvious "zoom" button... Maybe my browser ?
        
             | flobosg wrote:
             | The "save plot image" link allows you to download a full-
             | size figure that's more readable.
        
             | teruakohatu wrote:
             | It is being hit by HN. Shiny apps are often quite resource
             | intensive, because they are doing maths heavy computations,
             | but under normal usage it would run at a decent speed.
        
       | lamename wrote:
       | The Precision-Recall plot on page 17 caught my eye (Extended Data
       | Fig. 3a). Specifically the grey area.
       | 
       | "...grey shading indicates the valid range between perfect
       | performance and a random classifier."
       | 
       | What's with the diagonal cutoff at the bottom of the plot? I
       | understand where the dotted line comes from, but I expected the
       | grey shading lower bound to stop at the dotted line entirely.
        
       | SnowHill9902 wrote:
       | Feynman's first assignment required him to study the nervous
       | system of cats. So he went to the librarian in the biology
       | section and asked her if she could give him a map of the cat.
       | 
       | "A map of the cat, sir?" she asked, horrified. "You mean a
       | zoological chart!"
       | 
       | "From then on there were rumors about some dumb biology graduate
       | student who was looking for a map of the cat.", wrote Feynman in
       | his book Surely You're Joking Mr. Feynman.
        
       | rob_c wrote:
       | Whilst interesting, I'm left wondering. Why is it so hard to get
       | a straight answer of what this achieved.
       | 
       | Just to note I'm not bashing the work here (it appears solid
       | unlike a lot of papers from a lot of fields). I just assume I
       | must not be the target audience (which is a little odd for
       | nature) as I can't easily see what the main takeaway from this
       | should be. I'm not expecting an 'explain me like I'm 5', but a
       | short abstract-ending paragraph on what the research has achieved
       | would have been nice.
       | 
       | Unfortunately my takeaway otherwise is "thing is complex", "did
       | complex machine learning", "made a thing which approximates
       | reality". Made a model of it again in the lab based on this.
       | Therefore this means new therapy for??? (this last line is what
       | makes me pause and wonder is this here for grant/committe money,
       | or just to claim this was part of understanding/curing lupus in
       | 10 years?)
       | 
       | I'm all for trying to classify different interactions into groups
       | (even if that makes sense) and tring to understand the immune
       | system as a whole.
       | 
       | What (if anything) does this contribute to our current
       | understanding other than being a first attempt at framework to
       | classify a complex system? (not complaining, that in itself is a
       | reasonable goal).
       | 
       | If it is practically a first attempt at this. Why don't they say
       | so?
       | 
       | If this is one of a hundred similar models what makes this one
       | better/special?
        
         | w10-1 wrote:
         | > If this is one of a hundred similar models what makes this
         | one better/special?
         | 
         | There aren't any similar models. The complexity of the immune
         | system has defeated any systemic model. In most cases, even the
         | simple cascade from a single interaction is not modeled.
         | 
         | Most importantly, this is an *experimental* model: it
         | simplifies the complexity by focusing on a narrow range of
         | interactions that can be modeled in-silico and validated
         | experimentally, but whose collective behavior can *also* be
         | modeled and validated -- and, most importantly, tied to
         | systemic outcomes, of health and disease.
         | 
         | It defines a waltz of truth, that could be the fashion for
         | decades.
        
       | lake_vincent wrote:
       | Holy moly, I don't know anything about the content, but this is
       | straight up data science porn. Those visuals are stunning.
        
       | [deleted]
        
       | yosito wrote:
       | As someone who struggles with some vague immune system issues
       | with more questions than answers, I was shocked at how much
       | knowledge of the immune system is presented here. I was
       | immediately curious about how I can apply this knowledge to help
       | me understand my own immune issues. Unfortunately, I don't know
       | enough about biology and chemistry to understand much of this.
       | But I found this bit near the end encouraging, and a helpful
       | summary of what is presented here:
       | 
       | > More broadly, the integrated approaches that we pioneered here
       | for disentangling the immune system provide a framework for
       | future systematic investigations ... Our analysis and the methods
       | that we developed provide a template for future studies looking
       | at physical cell wiring networks in detail. From these combined
       | approaches, we may finally begin to disentangle cellular circuits
       | in immunity and beyond, bridging from individual protein
       | molecules to multicellular behaviour.
       | 
       | This seems to be a comprehensive model on a level that has never
       | been seen before, so in that sense, I'm very excited about it. I
       | just hope it doesn't take decades to trickle down into providers'
       | hands who can actually do something to help patients.
        
         | ramraj07 wrote:
         | Immunology in general is a weird field - we simultaneously know
         | a metric ton but also not much. It's like kind of we know why
         | we don't know. I remember in one of the final viva exams of a
         | fairly decent immunology grad student one of the committee
         | members started asking, "what does IL-1 do? IL-2?..." until the
         | student broke (this particular one did not, she had an answer
         | for every major IL in the lower single digits). But how many
         | interlukins can you even remember? There's no rhyme or Rythm
         | there, no med student mnemonics to get you through memorizing
         | their function.
         | 
         | Our system is complicated by how many components play
         | interconnected roles all the time it's just impossible to form
         | a mental model of it.
        
           | TaupeRanger wrote:
           | It's much like neuroscience. We can say a lot about what
           | individual cells and molecules do and how they interact with
           | other cells and molecules. And yet, when it comes to actually
           | modifying or changing anything, we're mostly hopelessly lost
           | and nearly all of our solutions are of the variety: "put this
           | drug into the bloodstream and see what happens, oops, that
           | didn't work and took 5 years to complete trials, time to try
           | the next one". The complexity is immense in biology and
           | medicine and we have a hard time dealing with any of it in a
           | meaningful way, other than to present extremely vague
           | theories without practical use (like talking about
           | "prediction" and "Markov blankets" in neuroscience, the
           | "discontinuity" theory of immunity, etc.
        
         | daoist_shaman wrote:
         | I'm sure the framework they've developed applies to more
         | intracellular systems than immunity. This could be an exciting
         | new language to map and define many different microbiological
         | processes.
        
         | laserbeam wrote:
         | > I don't know enough about biology and chemistry to understand
         | much of this.
         | 
         | The Machinery of Life by David Goodsell is a gorgeous
         | introductory book on the topic. I recommend it not because it's
         | the most comprehensive, but rather because it has amazing
         | illustrations and it's written for a general audience with the
         | purpose to be inspiring.
        
       | WebbWeaver wrote:
       | I am really, really excited for the day we are able to augment or
       | manipulate the immune system in a large and meaningful way.
       | 
       | For anyone who likes to visualize the whole kit and kaboodle of
       | current human knowledge check out the virtual metabolic human
       | database. They display an updated map on human metabolism
       | 
       | Recon human metabolism map https://www.vmh.life/#reconmap2
       | 
       | Paper overview of vmh
       | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6323901/
       | 
       | API Root of vmh https://www.vmh.life/_api
       | 
       | and obviously https://www.ebi.ac.uk/biomodels/ is pretty good too
       | 
       | human protein atlas
       | https://www.proteinatlas.org/humanproteome/metabolic
        
       | aaaaaaaaaaab wrote:
       | Jesus, what a mess... No wonder we have all sorts of allergies
       | and imnune issues.
        
         | svachalek wrote:
         | It's super complicated, but it's like alien legacy code from
         | the far future. We can nitpick the obvious flaws but we are
         | probably also completely underestimating some of the problems
         | it had to solve. A typical person's immune system can often
         | crack diseases in a few days that all the world's laboratories
         | have spent decades on.
        
         | chasil wrote:
         | Allergies are likely a byproduct of the immune reaction to
         | parasites.
         | 
         | They begin with mast cells that attach antibodies to their
         | exteriors, and when one attaches to something it recognizes,
         | the mast cell releases histamine and other signals to begin
         | inflammation. This can be enough to clear parasites that have
         | not evolved to address these effects.
         | 
         | These parasites are now rare in the developed world, and the
         | mast cell would likely be better disabled. I read several years
         | ago that work was being done on a method to remove the mast
         | cells' antibodies, which would stop much of an allergic
         | reaction.
        
           | aaaaaaaaaaab wrote:
           | Yeah, I know this hypothesis. I have a bunch of allergic
           | issues (atopic eczema, hay fever), and I've been
           | contemplating some kind of helminth therapy, but I'm too much
           | of a coward to actually do it...
        
       | Animats wrote:
       | This sounds like a major advance. Are there commentaries on it
       | from people who understand the implications? Is it useful for
       | rational vaccine design, for example?
        
         | w10-1 wrote:
         | > Is it useful for rational vaccine design
         | 
         | Not really. Vaccines -> antibodies produced from some of the
         | cells modeled.
         | 
         | This might help with adjuvants to vaccines (which are co-
         | administered with vaccines to increase effectiveness by ramping
         | up the immune system).
         | 
         | Vaccine design now is pretty "rational" (well-understood): Find
         | an immunogenic stable and accessible epitope on the pathogen,
         | and replicate that in the vaccine. It's the *production* of
         | vaccines that's hard.
         | 
         | COVID vaccine design was tricky because the key/unique epitope
         | is hidden by a conformational change until cell entry, but
         | still that was basically solved in a year. The magic lies in
         | the new mechanism for producing the immunogenic epitope: by
         | supplying RNA templates to your own cells to produce the
         | protein.
         | 
         | The hard design/modeling problem is auto-immunity, in all its
         | forms.
        
       | w10-1 wrote:
       | This is amazing work, and could be an essential methodology for
       | some time.
       | 
       | But I'd love to hear how they decided to call it a "physical
       | wiring diagram"; that must have been quite the discussion.
        
       | manholio wrote:
       | In terms of information security, as viewed by an infosec
       | engineer, biological systems seem to have incredibly weak
       | architecture. Hear me out, please.
       | 
       | If any piece of DNA code manages to find its way into the
       | nucleus, it's happily added to the cell "runtime" and has root
       | access to the system.
       | 
       | To defend against this, biology relies on multiple layers of
       | security, both physical, like the skin, and chemical, like the
       | secret protein password it requires to allow foreign DNA to
       | breach the cell membrane. But both are easily circumvented, for
       | example weak points exist in the physical layer and the protein
       | passwords are static and low entropy, easy to bruteforce by an
       | enemy that already has a botnet of infected hosts which produce
       | random permutations of these keys.
       | 
       | And once infection happens, the body response is sort of like the
       | experience of cleaning a Windows 98 which has been used by your
       | grandma to surf the internet for the last two decades, without
       | the option to do a fresh install (kill the host). It's messy and
       | insanely complex - the sort of thing you would expect blind
       | evolution to generate against a blind, brute-forcing script
       | kiddie.
       | 
       | You just have to wonder what are our chances on this planet if
       | intelligent and rational enemies, be they human or AI, gain the
       | knowledge, tools and motivation to attack biological systems and
       | intelligently design sophisticated attack vectors. Our most
       | precious systems are wide open, folks.
       | 
       | Perhaps some day, to prevent such attacks, we will take control
       | of this complex immune machinery and inject ourselves with highly
       | engineered "anti-viruses" built on the same info-sec principles
       | we build software on.
        
         | tgv wrote:
         | But that's where the "virus" metaphor comes from...
        
         | lamontcg wrote:
         | > Hear me out, please.
         | 
         | Nope. And I hate that phrase, it rarely pans out with anything
         | that makes any sense.
         | 
         | Yeah it would be great if Nabs were all we needed and they were
         | all sterilizing and permanent so any foreign pathogen was
         | instantly destroyed.
         | 
         | But the immune system has a complicated friend-or-foe problem
         | which pathogens are constantly trying to exploit.
         | 
         | I've had virus-triggered pericarditis before where presumably
         | igG Nabs to the cold virus I had managed to attack my
         | pericardium. Having T-cells and B-cells be latent and ready to
         | activate on infection and not constantly attacking surface
         | proteins is a good thing. Waning Nabs is a feature, not a bug.
         | 
         | And the multilayered approach to the immune system probably
         | means that immune escape of viruses is shuttled down the route
         | where viruses focus on Nabs, while the multiple kinds of TLA
         | subtypes and the secondary defense of the humoral immune system
         | mean that T-cell epitopes are not the focus of viral evolution
         | and immune escape.
         | 
         | The immune system evolved the way it did based on a 500M year
         | long arms race between eucaryotes and pathogens, it is really
         | quite good at what it does.
         | 
         | Of course there's weaknesses in it, but we have the advantage
         | of looking at the specific virus or pathogen that we're
         | concerned with and spending great effort to custom design
         | treatments, while the body needs to individually react to any
         | possible pathogen that the body might encounter on its own. We
         | can do custom bespoke treatment having analyzed the pathogen
         | extensively to start with, while the immune system's battle
         | starts the moment there's first contact by the individual
         | organism with the enemy. It works great for solving that latter
         | problem.
         | 
         | Most pathogens also never gain access to the nucleus and can't
         | be transcribed into the nucleus.
         | 
         | And even there, the reason why we have a placenta and are
         | mammals is likely because some organism was infected by a
         | retrovirus and learned to form syncytia and learned a knew
         | trick from a virus. Evolution can take a seeming "fault" like
         | that and turn it into a strength on the long-term.
         | 
         | Most likely all we need to do is be able to sit down with any
         | particular individual human's immune system and convince it to
         | attack something even though the immune system has concerns
         | about friendly-fire issues. Although the problem of doing
         | something like clearing EBV out of the neurons of someone who
         | is at risk of developing MS is problematic since you don't want
         | to kill a lot of EBV-infected neurons (which is probably a
         | "fault" of the nerve system rather than being a fault of the
         | immune system -- but one again it is likely a necessary "fault"
         | given the fact that we don't want to be scattershot blowing
         | away nerves). That is likely to look more like CRISPR treatment
         | to gene-edit the virus out of the DNA of those neurons. The DNA
         | viruses that incorporate into neurons of T lymphocytes, B
         | lymphocytes and neurons are indeed problematic, but that is a
         | very small number of pathogens that manage to get past all
         | those defenses that we have, there's a heavy amount of
         | survivorship/selection bias there. The hundreds of cold viruses
         | out there we clobber pretty routinely. For most everything else
         | the ability to regenerate cells with the ability to kill
         | infected cells works fine. The cells which "learn" stuff is
         | where things get really tricky. That is almost like a UEFI
         | rootkit. And our ability to prevent computer viruses is also
         | primitive, we have some general heuristics to quarantine virus-
         | looking code but it has a ton of false positives and we mostly
         | rely on distribution of signatures of the virus once
         | researchers have analyzed infected computers. The human immune
         | system can protect against viruses that the human race has
         | never encountered before.
        
         | artimunor wrote:
         | It's a feature, not a bug. As tux3 describes there has to be a
         | combination between easy access and dealing with threats.
         | 
         | I would like to add to tux3's comparison that in this analogy
         | the small criters are vital for cell-health, they bring
         | resources. And i would also like to add that nature has a way
         | of propagating the white/black-list as well which means that
         | predators get "marked" hence the mutation (a bit like a
         | criminal wearing a disguise?) element viruses have is so
         | important for them, and the thing that makes them so dangerous.
        
         | forgotmypw17 wrote:
         | As is common in IT, only the bare minimum necessary level of
         | security.
        
         | chasil wrote:
         | Actually, retroviruses have contributed ~8% of human DNA, so
         | you could say that past rootkits have been incorporated into
         | the current ("OS") platform. I understand the mammalian
         | placenta required the added viral genetic components to evolve.
         | 
         | These retrovirus fragments can surface as "transposons" where
         | they will copy themselves up to thousands of times over the DNA
         | of the cell, which can happen about once a month. There are
         | also "gypsy transposons" that encapsulate these viral fragments
         | in a package that can "infect" a neighboring cell.
         | 
         | Germline cells have special mechanisms to silence transposon
         | activity, otherwise reproduction would be much more
         | problematic.
        
         | aaaaaaaaaaab wrote:
         | Yeah, short of a complete rewrite in Rust, I don't see how we
         | could survive on the long run.
        
         | tibbydudeza wrote:
         | The issue is it was never designed - just trail and error that
         | nature got something that works but is kind of fragile but good
         | enough that it works for the majority of use cases.
         | 
         | Jerry rigged.
         | 
         | A colleague has been diagnosed with Type 1 diabetes recently
         | because his immune system decided last year the beta cells
         | making insulin in his pancreas is now fair game.
         | 
         | Then the recent papers show that cells in the pancreas duct has
         | the ability to regulate T cell activity as if this is a known
         | bug and more of us would get Type 1 than currently if it were
         | not the case.
         | 
         | As I said jerry rigged.
        
           | Projectiboga wrote:
           | My suggestions as a T1D, Melatonin upregulates the insulin
           | receptor so you need less. This also helps T2D. Second there
           | have been spontaneous remissions after the BCG Tuburculosis
           | vaccine, it some how stops that anti-islet cell immunity.
           | Bonus tip. Have them calculate half their weight in
           | kilograms, that gives the number of carbs a 100mg/dl blood
           | sugar equals. This helps with adjusting blood sugar up or
           | down incrementally. Finally serious low blood sugar often
           | start with a bleek mood or motor coordination loss. The
           | shifts in consciousness are the most emotionally and
           | interpersonally hard parts of this. They should not hide
           | their condition and should wear a bracelet with info, one can
           | become blackout drunk like in behavior. The new constant
           | sensors are amazing for learning and monitoring.
        
             | tibbydudeza wrote:
             | Well it is on my mind since he collapsed last week due to
             | hyperglycemia, the new monitoring (CGM)/insulin pumps are
             | amazing but you need a decent medical scheme and co-pay a
             | large part of it.
        
         | tux3 wrote:
         | I think you underestimate how good the immune system is! And
         | where the best cost/benefit security tradeoffs are, because
         | security is always a tradeoff. (The most secure system is a
         | dead system)
         | 
         | The body is constantly exposed to pathogens, all the time, in
         | everything you eat, the air you breathe, everywhere. It is as
         | if your laptop was downloading millions of random executables
         | from every site you visit and hapilly running them (the analogy
         | with Javascript and browser exploits just writes itself!)
         | 
         | Antibodies are in the metaphor both an allowlist AND a
         | blacklist. Anything that isn't a well-known protein made by the
         | body (allowed) is fair game for antibodies to bind to. You make
         | quintillions of these that will bind to anything under the sun.
         | Once they find a pathogen, it goes on the blacklist and more
         | specific antibodies are made for it, that's adaptive immunity.
         | There are many further layers and defenses on top of that, of
         | course, but compared to infosec this is already much stricter
         | filtering than a typical endpoint protection product.
         | 
         | It's easy to look at it and say hey we should lock down the
         | cell membrane by adding randomly generated passwords and
         | rotating them, that will improve security! But that's not
         | realistic, a lot of simple things need to go through the cell
         | membrane all the time.
         | 
         | That would be like requiring all living beings to show a
         | passport before entering your country. Your intent is that you
         | mostly care about catching criminals, but the border is mostly
         | crossed by birds and small critters. The cell is the same, lots
         | of things go in and out all the time, and they're too simple to
         | carry any sort of identification. That's like requiring birds
         | to have a passport.
        
           | manholio wrote:
           | > But that's not realistic, a lot of simple things need to go
           | through the cell membrane all the time.
           | 
           | But surely something that contains an executable payload
           | (DNA/RNA) needs to be better scrutinized than a simple
           | nutrient. Runtime alterations of the cell code are
           | practically never required, the fact that any code that
           | enters the cell is fair game to execute and even to
           | permanently alter the nucleus "binary"(retroviruses) strikes
           | as a bad practice. A static host-key, unique per individual,
           | would stop all such viruses.
           | 
           | So you cannot shake the impression that evolution does not
           | really care about the information security of any given host.
           | What it cares about is overall success of the gene while
           | allowing for sufficient variation and flexibility - the
           | retroviruses are just a tool among many to induce such
           | genetic variability.
           | 
           | Nothing I say above should be taken as dismissing an
           | exceptionally intricate and developed system, just pointing
           | out the different way a rational attacker would approach the
           | problem and that the defenses against such an attack would be
           | fundamentally different than what evolution had to deal with
           | in the past.
        
             | tux3 wrote:
             | I wouldn't really say that it doesn't care about
             | information security.
             | 
             | The DNA is actually pretty well protected, tightly wound
             | inside the nucleus, which has pretty strong access control
             | checks on what can enter and what can leave. It's always
             | possible to break those protections, but a lot of effort
             | went into "sandboxing" the rest of the cell and the
             | nucleus.
             | 
             | There are also strong checks on code circulating where it
             | isn't supposed to be. If you let RNA or DNA run around in
             | plain sight in the blood, your immune system will react
             | immediately with extreme prejudice and excessive violence.
             | 
             | But of course viruses and vaccines wrap that code in a
             | protective layer (much like malware wraps itself with
             | packers, obfuscation, and sophisticated delivery methods
             | before reaching the target).
             | 
             | And then like you said, that protective vesicle needs some
             | sort of static key to enter cells, it needs to target an
             | appropriate receptor to gain entry.
             | 
             | Where things get complicated is that, while it would be
             | really good to have per-host random keys, instead of a
             | fixed set of receptors than anyone can trigger by 'putting
             | a square shape in the square hole', the lock and key system
             | of proteins is not one where you can generate a random
             | receptor and the key that matches it from a seed, like you
             | could in cryptography.
             | 
             | It takes huge effort and long optimization times to find a
             | protein that matches a random receptor pretty well. The
             | consequence is that it's non-trivial for viruses to jump
             | between animals that have slightly different receptors, or
             | to find a new target in a particular host. It takes a lot
             | of optimization time to find even just a single static key
             | that matches.
             | 
             | But the corollary is that it's nigh impossible for a human
             | body to add a random per-host mutation to every receptor
             | and everything that binds to it. It's a good idea in
             | infosec, but because of the way proteins and chemistry work
             | in biology, we don't have any mechanism to create the sort
             | of defenses you care about.
             | 
             | Evolution does care very much about retroviruses, and in
             | fact the defenses it put in place are able to brutally
             | murder the overwhelming, oppressive majority of them. I
             | think the impression that it's missing some obvious
             | defences is due to the fact that the kind of defense that
             | works really well in biology is very different from the
             | kind that works well in infosec.
             | 
             | There are cases where evolution goes wrong, because it
             | optimizes for the replication of the genes instead of the
             | wellbeing of the host, that's true. But in the case of
             | retroviruses, the host almost always loses fitness after an
             | infection, so defending the genetic code against viruses
             | tends to be strongly aligned with what evolution "cares
             | about" (insofar as it "cares" about anything)
        
       | kleer001 wrote:
       | that's f-n gorgeous, I have only a slight idea what it means, but
       | it's beautiful, so much work
        
         | andreareina wrote:
         | Would be a good addition to http://biochemical-
         | pathways.com/#/map/1
        
           | gzer0 wrote:
           | Amazing resource. Totally forgot about the existence of this;
           | definitely helped during medical school. Thanks for the share
           | :)
        
       | gzer0 wrote:
       | https://static-content.springer.com/esm/art%3A10.1038%2Fs415...
       | 
       | Link to the technical overview and mathematic modeling that has
       | massive implications for the field of immunology as a direct
       | result of this research.
       | 
       | > _If cell-to-cell adhesion is mostly determined by the binding
       | of complementary receptors on the surfaces of those cells, and a
       | relatively complete listing of these receptors has now been
       | measured, then it should be possible to predict which cells are
       | most likely to physically interact with each other by counting up
       | their number of binding receptors._
        
       | photochemsyn wrote:
       | This is kind of stunning. They appear to have discovered
       | something like 30 novel (previously unknown) immune cell receptor
       | interactions (Fig 1). Then they built a quantitive model, looked
       | into where these interactions are localized in the body, and lots
       | more beside. A truly ridiculous amount of information for a
       | single paper. This seems to be the 'what's it all about'
       | paragraph in the paper:
       | 
       | > "The immune system is distinctive for being a distributed
       | system. It is not fixed to a single localized organ in the body,
       | but rather is made up of numerous specialized cell types that
       | must adaptably organize their intercellular connections to
       | respond to pathogens and other threats wherever they may appear.
       | We provide a systematic and quantitative view of the cell-surface
       | proteins that enable immune cells to dynamically wire their
       | interactions. The receptor interactions that we report in our
       | network each merit further individualized study to characterize
       | their full roles in health and disease."
       | 
       | For those interested in computational modeling (basically they
       | simulate immune cells circulating freely within the body and
       | interacting based on their receptor types), here's the
       | supplementary description link (pdf), which is enough for a whole
       | paper on its own.
       | 
       | https://static-content.springer.com/esm/art%3A10.1038%2Fs415...
        
         | photochemsyn wrote:
         | After looking at this a bit more, here's something interesting.
         | First, it's a very physical model, treating cells as 3D
         | entities with 2D interactions (cell surfaces), and they use
         | their measured binding constants (essentially a measure of
         | protein-protein stickiness across all their proteins) as a key
         | parameter, along with measures of protein expression in various
         | immune system cell types. They're classified into: CD4 T cells,
         | Helper CD4 T cells, Natural killer cells, CD8 T cells,
         | Dendritic cells, Monocytes, Regulatory T cells, B cells. This
         | is all quite complex, here's a simplified 6 min overview of
         | some of their roles, note the importance of receptor-receptor
         | interactions at every stage:
         | 
         | https://www.youtube.com/watch?v=6eMh0Vpyoik
         | 
         | For a nice visualization of immune cells attacking cancer
         | cells:
         | 
         | https://www.youtube.com/watch?v=K09xzIQ8zsg
         | 
         | So, this is a complex dynamic network, and a key feature of
         | such networks is that a change at one point in the network can
         | percolate across the entire network, which can be critical to
         | their normal functioning, as well a play roles in failure
         | /pathology. The ability to model such casading effects could be
         | game-changing in terms of developing treatments such as
         | targeting cancer cells, blocking autoimmune activation, etc.
         | From supplement:
         | 
         | > "Another direct test of the predictive power of this model
         | would be to experimentally block specific cell-surface protein
         | interactions (such as by adding recombinant ligands that
         | competitively inhibit their receptors' interactions) and gauge
         | how cell-to-cell contact frequencies change. If these changes
         | are predictable from our "ground-up" mass action kinetics
         | model, that would demonstrate the utility of our systematic
         | approach."
        
           | dylan604 wrote:
           | Thanks for those links. I'm not an oncologist, nor do I play
           | one on TV, so I've only paid a cursory glance to where the
           | current understanding of cancer cell behavior was. After
           | watching the second video you linked, I'm now extremely
           | curious about this field, and kind of wish I could go back in
           | time to chose a different career path. The amount of details
           | now known on how cells, proteins, etc work is totally
           | fascinating to me.
        
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