[HN Gopher] Scientists: Protein IL-17 fights infection, acts on ...
       ___________________________________________________________________
        
       Scientists: Protein IL-17 fights infection, acts on the brain,
       inducing anxiety
        
       Author : wglb
       Score  : 97 points
       Date   : 2025-04-14 15:54 UTC (7 hours ago)
        
 (HTM) web link (medicalxpress.com)
 (TXT) w3m dump (medicalxpress.com)
        
       | wglb wrote:
       | Related paper on receptors:
       | https://www.cell.com/cell/abstract/S0092-8674(25)00279-X
       | 
       | Paper suggesting mood alteration:
       | https://www.cell.com/cell/abstract/S0092-8674(25)00278-8
        
       | idontwantthis wrote:
       | Any idea if this protein has any relation with seratonin? Could
       | the effect of SSRIs be related in any way?
        
         | boredemployee wrote:
         | in case anyone wondering:
         | 
         | https://en.wikipedia.org/wiki/Selective_serotonin_reuptake_i...
        
         | noncoml wrote:
         | That's a great question
        
         | xattt wrote:
         | Isoniazid has an antidepressant effect as a weak MAOI, but any
         | interaction with IL-17 would be indirect and related to a
         | reduced microbial load in TB.
        
         | internet_rand0 wrote:
         | seratonin is a molecule
         | 
         | this is a protein[1]
         | 
         | this question strikes me as asking if a quark has a relation
         | with an atom
         | 
         | [1] https://en.wikipedia.org/wiki/Interleukin_17
        
           | nartho wrote:
           | A protein is a molecule What a strange reply
        
             | jiggawatts wrote:
             | "Chemistry literacy" is very poor in the general public
             | because it has very few everyday applications, so
             | everything learnt at school just drops out of people's
             | brains.
             | 
             | That's why your hear nonsense like "It has _chemicals_ in
             | it!!!"
             | 
             | It's also why you regularly see science fiction where
             | characters can grow in seconds, totally breaking the law of
             | conservation of matter.
        
         | carabiner wrote:
         | Serotonin has little relevance to depression and was more of a
         | cute story doctors told patients in the '90s, that they were
         | told by pharma reps.
        
           | api wrote:
           | AFAIK the truth is a little more complex: SSRIs do work for
           | many people, but we don't really understand why and it's not
           | as simple as 'more serotonin good.' They also don't work for
           | everyone, and we don't understand why they don't work for
           | some people either.
        
         | dayvigo wrote:
         | Serotonin can decrease IL-17 production, and IL-17 is highly
         | elevated in depressed patients. Inflammation is elevated in
         | depressed patients more generally, but baseline IL-17 levels
         | specifically appear to be a good predictor for antidepressant
         | response[1]. Anti-depressants are pretty much universally anti-
         | neuroinflammatory.
         | 
         | [1]: https://pubmed.ncbi.nlm.nih.gov/28698115/
        
         | FollowingTheDao wrote:
         | Yes, cytokine like IL 17 increase an enzyme called IDO which
         | pulls tryptophan away from the serotonin production pathway.
         | 
         | https://www.researchgate.net/figure/Effect-of-IDO-on-seroton...
        
       | ashoeafoot wrote:
       | I guess depression makes for excellent self quaratine?
        
         | biomcgary wrote:
         | Yes, one would expect kin / group selection to play a role.
        
       | jagaerglad wrote:
       | this is rather amazing, I've always thought that my observation
       | that I feel better in my brain after a good fever has to be
       | imagination
        
         | yapyap wrote:
         | Yeah cause your point of reference is feeling like shit when
         | you are feverish.
        
           | gusgus01 wrote:
           | Actually, there are some studies that show a anti-depressive
           | effect from exposure to heat/fever like conditions. These are
           | just two from a rudimentary Google search to check if I was
           | remembering correctly.
           | https://pmc.ncbi.nlm.nih.gov/articles/PMC6519523/
           | https://www.colorado.edu/asmagazine-archive/node/2080
        
         | gehwartzen wrote:
         | I take mustard baths occasionally (about a cups worth) when I
         | feel a cold or virus coming on which seems to kind of fast
         | track clearing out whatever is causing it. Feel amazing after.
         | Better than baseline as I've found a similar effect when not
         | sick.
        
           | vosper wrote:
           | A cup of mustard powder? What does it feel like and how did
           | you come across this?
        
       | bitwize wrote:
       | Possibly related to:
       | https://en.m.wikipedia.org/wiki/Sickness_behavior
        
       | eveningsteps wrote:
       | Surprisingly enough, this partially exposes the link between
       | depression and some of the autoimmunal diseases. One example is
       | how patients with psoriasis have significantly elevated levels of
       | proteins from the IL-17 family (namely, IL-17A, IL-17C, and
       | IL-17F) - up to 4 to 8 times above nominal values.
       | 
       | At the same time, bimekizumab, one of the bleeding-edge psoriasis
       | and psoriatic arthritis treatments, suppresses production of
       | IL-17A and IL-17F (methotrexate does that, too, albeit to a much
       | smaller degree). As a result, people receiving IL-17 suppressors
       | become happier over the course of years, and not only due to
       | months-long remission - I had a chance to see this in one of the
       | experimental treatment programs.
        
         | FollowingTheDao wrote:
         | Another aspect of this is that high levels of IL 17 can cause
         | mania in bipolar patients.
         | 
         | https://pubmed.ncbi.nlm.nih.gov/27295856/
         | 
         | I do not know why doctors are so hesitant to link the immune
         | system and mood disorders. I have schizoaffective disorder and
         | I see this expressing myself every time. For example, when I
         | caught Covid, I had one of the worst psychotic episodes in my
         | life. None of my doctors really cared about this important
         | correlation.
         | 
         | And I will scream this from the rooftops for as long as I can;
         | mood disorders are immune disorders.
        
           | derefr wrote:
           | > I do not know why doctors are so hesitant to link the
           | immune system and mood disorders.
           | 
           | People who call themselves _doctors_ -- e.g. neurologists --
           | generally aren 't hesitant to do this. But psychiatrists --
           | and even moreso, therapists -- generally are. And
           | psychiatrists+therapists lead the conversation on mood
           | disorders, since that's who everyone is talking to about
           | their mood disorders.
           | 
           | IMHO it's just the hammer-and-nail thing. To a cardiologist,
           | every medical problem is seen through a potentially
           | cardiovascular lens; to an oncologist, every problem is a
           | question of what type of cancer could cause it.
           | 
           | Psychiatrists are technically medical doctors, but they spend
           | their entire careers (after a few short years of school)
           | focusing on psych cases; where these patients' problems
           | either _are_ purely psychological (e.g. conditioned-response,
           | traumatic-response, coping /defensive, attachment-related,
           | etc.), or at best "we don't know" the degree to which they're
           | psychological vs organic. (If we can recognize a problem as
           | purely organic from the outset, that problem doesn't end up
           | in the hands of a psychiatrist!) And either way, they usually
           | see good results in clinical practice from treating the
           | patient's mind, rather than addressing organic signs/symptoms
           | directly. Even when they prescribe medication, they're
           | measuring their success on a mental basis (using
           | questionnaire-based instruments used to gauge mental changes)
           | rather than observing changes in e.g. measurable behavioral
           | signs. The problems they're faced with, and the successes
           | they have _via_ these models, reinforce in psychiatrists a
           | mind-centered mental model  / worldview for psychiatric
           | disease. (A model which is "the right one" to use in many
           | psychological diseases! But not for many others.)
           | 
           | And therapists aren't even medical doctors. They never learn
           | much-at-all in school about potential organic causes of
           | psychological (or medical) problems. They focus purely on
           | this lens of "the mind", ignoring the lens of "the brain as
           | an organ" entirely. This means that in clinical practice,
           | when confronted with a problem that has both mental and
           | organic aspects, a therapist will tend to ignore the organic
           | aspects; and when confronted with a problem where the organic
           | aspects are too large to ignore, the therapist will simply
           | refer to a psychiatrist (or neurologist, _maybe_ ) -- with no
           | follow-up, and thereby, no way to end up learning what the
           | patient's problem actually was and thereby evolving the
           | neurological side of their understanding.
        
             | xerxes901 wrote:
             | I don't know what you're basing this on. Good psychiatrists
             | absolutely "call themselves doctors" and definitely seek to
             | exclude or treat organic causes of psychiatric symptoms.
             | All the psychiatrists I know absolutely understand there's
             | a link between the immune system and mood disorders and
             | will involve immunology/rheumatology for these things.
             | 
             | Your ideas about how psychiatry is practiced might have
             | been correct in the 1950's but they're a world away from
             | how it's done in the 2020s.
        
         | Zufriedenheit wrote:
         | Is that ,,becoming happier" also observed with TNF blockers
         | like Adalimumab?
        
         | null_name wrote:
         | Interesting, I take risankizumab, which looks like it
         | indirectly suppresses IL-17 (through suppressing IL-23A). I've
         | been on it for a bit less than a year, and I can't say if I've
         | had improved mood. Maybe? It definitely fixed the psoriasis.
         | Might also have contributed to me getting sick more often,
         | though.
         | 
         | I wish I had kept logs with some sort of self-screen depression
         | instrument now (maybe the BDI? I don't like the PHQ-9). Might
         | as well start now.
        
         | AnthonBerg wrote:
         | Ketamine curbs IL-17 secretion pretty hard. Psoriasis tends to
         | vanish pretty quick after a therapy session.
        
         | hirvi74 wrote:
         | Based on your knowledge and experiences, do you think the
         | benefits are worth the potential side-effects?
         | 
         | I fully understand that after a certain point of disease
         | severity, the right choices tend to become more apparent.
         | However, I have been offered such medications in the past, but
         | I have always refused.
         | 
         | From what I understand, many of the serious side-effects are
         | rare. However, once Pandora is out of the box, it's not always
         | easy to get her back inside.
        
       | chaps wrote:
       | This is interesting! I've been having some pretty bad
       | intermittent panic attacks over the past year or so and a thing
       | I've noticed is that I have general inflammation across my body
       | along with the panic attacks. For a long while I thought it was
       | an infected tooth, but with that fixed and the panic attacks
       | still ongoing, I'm not sure! But this is a nice confirmation that
       | there's some correlation.
        
       | mleonhard wrote:
       | Related paper on the immune system triggering anxiety: "Stress-
       | Induced Metabolic Disorder in Peripheral CD4+ T Cells Leads to
       | Anxiety-like Behavior" https://doi.org/10.1016/j.cell.2019.10.001
       | 
       | Related: "N-acetylcysteine as a new prominent approach for
       | treating psychiatric disorders" https://doi.org/10.1111/bph.15456
       | section "2.3 Regulation of inflammatory mediators".
       | 
       | N-acetylcysteine (NAC) is considered safe and is sold as a diet
       | supplement in USA and many other countries. If you suffer from
       | anxious feelings, 1200mg/day NAC may reduce them a lot.
        
       ___________________________________________________________________
       (page generated 2025-04-14 23:01 UTC)