Interferons as mediators in ME/CFS

Jonathan Edwards

Senior Member (Voting Rights)
I apologise for trying to make sense of all the threads around DecodeME with another thread but I see interest in collecting thoughts on interferons as candidates. This follows on from recent discussion on the Genetics OLFM4 thread but it goes back much further.

"Interferon' was discovered by two people in 1957, one being a close family friend who died in his forties when I was a child (Alick Isaacs, to a child a wonderfully amusing and kind 'uncle'). It turned out to be several things and we are probably mostly interested in alpha and beta (type 1 Ifs) and gamma (type 2). My understanding is that although these are separate molecules and have different repertoires they often up-regulate expression of the same proteins and pathways.

Interest in ME/CFS goes back to the observation that alpha interferon therapy causes fatigue. Robert Phair picked up on alpha interferon as a key mediator in his itaconate shunt idea. @jnmaciuch and I have been discussing the merits of alpha and gamma interferons for some months. Gamma interferon seemed plausible as a T cell signal that might make more sense than some of the cytokines like TNF or IL6 as part of a persisting abnormal immune response. Now @jnmaciuch has pointed out that we might use alpha interferon as a way to tie in several gene variant hits in DecodeME. At least some of those might link to gamma interferon too, but maybe not all.

My sense is that discussion of pooled knowledge on these molecules and pathways would be a good place to start in trying to build ideas around DecodeME results. Key questions are going to be 1. which tissues might specifically be hosting local, maybe hidden, interferon-based signalling and how that might relate to symptoms 2. how to understand time courses for inappropriate interferon signalling over both short and long term in ways that would make biological sense and fit symptomatology.

I think that is about enough for an introductory post but I will add a few quick thoughts.
1. I am coming around to the idea that gamma interferon may be involved early on in disease triggering but that alpha (?+beta) may well take over long term.
2. For me the problem with alpha is how the body 'learns' to overproduce or over-respond with the long term dynamics of ME/CFS but the increased focus on brain (or maybe neurons) from DecodeME might be relevant there. (Learning to make more gamma is the standard job of T cells.)
3. How best do we tie the DecodeME hits together into a story and what awkward questions would that raise.
 
I'm sure we've talked about this before but I forget - Is anything known about the basic biology of why IFN type 1/2 causes fatigue? I seem to recall that it not just causes fatigue acutely but can also lead to an enduring fatigue that last long after IFN therapy ends. Possibly by interacting with the DRGanglia or someway with the more permeable parts of the BBB, or involved in sensitising peripheral neurons directly at their termini. Is there maybe basic biology work that could be done here maybe in mouse models.

Am I right in saying in lupus the inteferon production is driven by taken up nucleic acid immune complexes? - something which would be absent in ME. I'm guessing neurons and glia respond to type 1 IFNs just like any other cell type does - how does it affect the maintainence and function synapses?
 
Hoping this helps in any way :

1) Likely tissues hosting local, semi‑hidden IFN signalling​


Think “hard‑to‑biopsy, richly innervated, barrier or ganglion tissues” where small, persistent triggers can keep IFN circuits smouldering without flooding peripheral blood.


Neuro-immune interfaces


  • Dorsal root & autonomic ganglia (DRG, nodose, sympathetic chain): Latent neurotropic viruses, mitochondrial damage, or sterile nucleic acids can prime cGAS–STING/RIG‑I/MDA5 in satellite glia & resident macrophages → tonic CXCL9/10/11, ISGs, and sensory/autonomic hypersensitivity (pain, orthostatic symptoms, “flare on exertion”).
  • Meninges & choroid plexus: Border-zone immune hubs; low‑level type I IFN here can reshape CSF cytokines and sickness-behaviour circuits with minimal blood signal.
  • Brain microglia/astrocytes (select nuclei): Local IFN can alter sleep–wake, hypothalamic set points, and central autonomic control → non‑restorative sleep, fatigue, thermoregulatory quirks.

Barrier epithelia with dense innervation


  • Olfactory epithelium & nasal mucosa: A classic niche for persistent epithelial ISGs; signals project to limbic/brainstem circuits → sensory intolerance, malaise.
  • Gut mucosa (Peyer’s patches, myenteric plexus): pDC‑rich, microbe‑dense; sustained type I IFN can disturb epithelial energy handling and vagal signalling → post‑exertional malaise (PEM), GI dysautonomia.
  • Lung small airways & marginal alveolar regions: Intermittent epithelial IFN without overt inflammation → exertional breathlessness out of proportion to spirometry.

Endothelium & muscle–tendon units


  • Microvascular endothelium (skeletal muscle, brain): Type I IFN reduces endothelial glycolysis and NO bioavailability → early muscle fatigability, brain fog under load.
  • Myotendinous junctions & fascia: Local macrophage/tenocyte IFN tone could amplify delayed-onset pain and stiffness after exertion without CK spikes.

Secondary lymphoid tissues


  • Draining lymph nodes/tonsils with intermittent plasmacytoid dendritic cell (pDC) activation → sustained “tonic” IFN‑α that imprints circulating cells while staying below detection in plasma most days.
 
I apologise for trying to make sense of all the threads around DecodeME with another thread but I see interest in collecting thoughts on interferons as candidates. This follows on from recent discussion on the Genetics OLFM4 thread but it goes back much further.

"Interferon' was discovered by two people in 1957, one being a close family friend who died in his forties when I was a child (Alick Isaacs, to a child a wonderfully amusing and kind 'uncle'). It turned out to be several things and we are probably mostly interested in alpha and beta (type 1 Ifs) and gamma (type 2). My understanding is that although these are separate molecules and have different repertoires they often up-regulate expression of the same proteins and pathways.

Interest in ME/CFS goes back to the observation that alpha interferon therapy causes fatigue. Robert Phair picked up on alpha interferon as a key mediator in his itaconate shunt idea. @jnmaciuch and I have been discussing the merits of alpha and gamma interferons for some months. Gamma interferon seemed plausible as a T cell signal that might make more sense than some of the cytokines like TNF or IL6 as part of a persisting abnormal immune response. Now @jnmaciuch has pointed out that we might use alpha interferon as a way to tie in several gene variant hits in DecodeME. At least some of those might link to gamma interferon too, but maybe not all.

My sense is that discussion of pooled knowledge on these molecules and pathways would be a good place to start in trying to build ideas around DecodeME results. Key questions are going to be 1. which tissues might specifically be hosting local, maybe hidden, interferon-based signalling and how that might relate to symptoms 2. how to understand time courses for inappropriate interferon signalling over both short and long term in ways that would make biological sense and fit symptomatology.

I think that is about enough for an introductory post but I will add a few quick thoughts.
1. I am coming around to the idea that gamma interferon may be involved early on in disease triggering but that alpha (?+beta) may well take over long term.
2. For me the problem with alpha is how the body 'learns' to overproduce or over-respond with the long term dynamics of ME/CFS but the increased focus on brain (or maybe neurons) from DecodeME might be relevant there. (Learning to make more gamma is the standard job of T cells.)
3. How best do we tie the DecodeME hits together into a story and what awkward questions would that raise.

Alpha interferon is one of the mooted causes of post Lyme in some patients which may mean overlap with ME.
 
I'm sure we've talked about this before but I forget - Is anything known about the basic biology of why IFN type 1/2 causes fatigue?
Looking at the literature it seems that exposure to elevated interferon can lead to lasting changes in parts of the brain (but my impression is the timeframes studied were weeks/months, not years/decades).

A study found ventral striatal/basal ganglia were affected.

A study failed to find clear microglial activation.

PS: cancer-related fatigue could also provide some clues.
 
Last edited:
I'm sure we've talked about this before but I forget - Is anything known about the basic biology of why IFN type 1/2 causes fatigue? I seem to recall that it not just causes fatigue acutely but can also lead to an enduring fatigue that last long after IFN therapy ends. Possibly by interacting with the DRGanglia or someway with the more permeable parts of the BBB, or involved in sensitising peripheral neurons directly at their termini. Is there maybe basic biology work that could be done here maybe in mouse models.
Type I (or II) interferons don't signal fatigue directly, but besides immune system mediated effects, it does lead to other changes including sensitisation of afferent nerves in both the dorsal horn and dorsal root (which can be due to it being involved in the tissue repair process), metabolic/endocrine effects etc.

Can anyone tell me what ifn gamma and TNF gene expression assays actually measure?

Gene expression focuses on messenger RNA that codes for the particular genes.

The tests tend to focus on specific cell types, eg Peripheral blood mononuclear cells, but keep in mind this assay result isn't the same as the expression of those genes in other (in vivo) tissue environments.
 
Type I (or II) interferons don't signal fatigue directly, but besides immune system mediated effects, it does lead to other changes including sensitisation of afferent nerves in both the dorsal horn and dorsal root (which can be due to it being involved in the tissue repair process), metabolic/endocrine effects etc.



Gene expression focuses on messenger RNA that codes for the particular genes.

The tests tend to focus on specific cell types, eg Peripheral blood mononuclear cells, but keep in mind this assay result isn't the same as the expression of those genes in other (in vivo) tissue environments.
Thanks. I had these tests on blood but I don't know which cells I assume white ones of one sort or another. Routinely elevated but is it an immune marker rather than immune activity? (Hope this is not thread hijacking)
 
2. For me the problem with alpha is how the body 'learns' to overproduce or over-respond with the long term dynamics of ME/CFS

Is there anything to learn from the sort of arms race that can get set up in toxoplasmosis infection in healthy people?

Added: I'm not trying to suggest ME/CFS might be caused by a parasite, just asking whether the dynamics could be similar.

(Might be a ridiculous question, I don't have enough understanding to know!)
 
Last edited:
What did you think of the KCL paper on persistent fatigue and interferon alpha @Jonathan Edwards ?

I can't remember if I looked at it in detail before. It is interesting in that it suggests that people with persistent fatigue after interferon alpha may have a prior higher responsiveness flagged by IL-10 and IL-6 but that these cytokines are not mediating the fatigue.

I do think it may be useful to check that DecodeME picked up nothing on gene variants that encode higher IL-6 responses to things but maybe from the KCL study we should not necessarily expect it. Maybe the higher IL-6 levels at KCL were an indication of IFN receptor sensitivity with the pathology being through something else being IFN sensitive. It is all rather complicated but maybe tractable.
 
Is there anything to learn from the sort of arms race that can get set up in toxoplasmosis infection in healthy people?

Added: I'm not trying to suggest ME/CFS might be caused by a parasite, just asking whether the dynamics could be similar.

(Might be a ridiculous question, I don't have enough understanding to know!)
Toxo is another one I've had
 
My post in the OLMF4 thread about possible related candidate genes:

Looking through the candidate list again, I think there's an interesting thread that ties several of the top genes together, which is regulation of type I (alpha/beta) interferon signaling.

OLFM4

No directionality info from eQTLs.

PEBP1



TRIM38
(type I interferons are one of the main products of TLR and cGAS-STRING/viral RNA sensing)



KLHL20


E3-ubiquitin ligases are typically associated with degradation of interferon, but it might not be so cut and dry.

ZNFX1

I'll note that though this is an interferon-stimulated gene, it's activity as a dsRNA sensory would also trigger interferon.


And interestingly, PRDX6, a cousin of PRDX5--which is inhibited by itaconate to allow type I interferon production in macrophages


The BTNs could also be part of the story via their regulatory effect on TLRs. Plus TLR/type I interferon signaling utilizes MAPK signaling, which potentially implicates ZNF322 (increased) and SUDS3 (increased).Plus PTGIS (decreased expression), since prostaglandins are known to inhibit interferon signaling in some contexts.

Just throwing things at a wall to see what sticks based on the assumption that at least some of these genes are actually affected by the identified SNPs. The directionality of most of these (where eQTL data is provided) seems to generally be in the direction of enhanced interferon in ME/CFS (either increased expression in genes that are positive regulators or decreased in genes that are negative regulators), so that would be some weak evidence against the idea that these SNPs are driven by [edit: poorer protection in ME/CFS cases] against viral infections.

[Edit: and acknowledging that I’m probably biased here since I already think there’s a good case for type I interferons in ME/CFS]

Some other threads that may be relevant:
Thread 'Basal Ganglia Hypermetabolism and Symptoms of Fatigue during Interferon-α Therapy (2007), Capuron et al.'
https://www.s4me.info/threads/basal-ganglia-hypermetabolism-and-symptoms-of-fatigue-during-interferon-α-therapy-2007-capuron-et-al.44562/

A study showing differential basal ganglia metabolism correlated with fatigue in interferon therapy, small sample size and only looking at limited areas of the brain, not sure how generalizable the findings might be.

Thread 'Inhibition of Histone Deacetylation Induces Constitutive Derepression of the Beta Interferon Promoter [...] , 2001, Shestakova et al.'
https://www.s4me.info/threads/inhib...erferon-promoter-2001-shestakova-et-al.44830/
An in-vitro study showing that the change from “active” to “constitutive” interferon production after resolution of infection is mediated by epigenetic changes.

A review of regulation of constitutive interferon beta production—a potential list of things that could go wrong in suppressing baseline interferon production.

A good review on interferons in lupus. @chillier this might address your earlier question of where interferons come from in lupus—it appears that in the bloodstream it is derived from pDCs and neutrophils responding to apoptotic junk, but there is some evidence of tissue cells generating it on their own in skin as well.

@hotblack some of these links might be of interest to you as well
 
Additionally:

A review of how mtDNA release leads to a type I interferon signaling response in exercise in healthy people.

Thread 'Interferon-stimulated gene TDRD7 interacts with AMPK and inhibits its activation to suppress viral replication and pathogenesis, Chakravarty+'
https://www.s4me.info/threads/inter...plication-and-pathogenesis-chakravarty.44426/
A study showing that interferon administration affects AMPK activation through interferon stimulated gene TDRD7. Just including it because it happens to align quite well with findings in muscle cultures from the Newton lab:

Thread 'Abnormalities of AMPK Activation and Glucose Uptake in Cultured Skeletal Muscle Cells from Individuals with Chronic Fatigue Syndrome, 2015, Brown+'
https://www.s4me.info/threads/abnor...th-chronic-fatigue-syndrome-2015-brown.44427/

Thread 'Pharmacological activation of AMPK and glucose uptake in cultured human skeletal muscle cells from patients with ME/CFS (2018) Newton et al'
https://www.s4me.info/threads/pharm...-patients-with-me-cfs-2018-newton-et-al.3607/

Though these studies were small, with Fukuda criteria, and need further validation. If the findings are real, they might present an explanation for interferon-induced rapid fatiguability in muscle, as well as a potential mechanism by which mtDNA release could occur at much lower thresholds of muscle use and trigger an exacerbated interferon response (potential PEM explanation).
 
Also may or may not be relevant, but I happened across this paper on neurological features in mouse models of lupus that mentioned several synaptic adhesion genes (NLGN1 and 2 specifically mentioned, which came up in the Zhang et al. paper) being interferon stimulated genes in neurons.


Honestly not sure how it relates but something interesting to note nonetheless.
 
This popped up in social media today. Don’t know if it’s relevant? I don’t have access.

Type I interferons (IFN-Is) are cytokines with potent antiviral and inflammatory capacities. IFN-I signaling drives the expression of thousands of IFN-I–stimulated genes (ISGs), whose aggregate function results in the control of viral infections. A few of these ISGs are tasked with negatively regulating the IFN-I response to prevent overt inflammation. ISG15 is a negative regulator whose absence leads to persistent, low-grade elevation of ISG expression and concurrent, often self-resolving, mild autoinflammation. The limited breadth and low-grade persistence of ISGs expressed in ISG15 deficiency are sufficient to confer broad-spectrum antiviral resistance. Inspired by the antiviral state of humans with ISG15 deficiency, we identified a nominal collection of 10 ISGs that recapitulated the broad antiviral potential of the IFN-I system, which typically induces the expression of thousands of ISGs. The expression of this 10-ISG collection in an IFN-I–nonresponsive cell line increased cellular resistance to Zika virus, vesicular stomatitis virus, and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). A lipid nanoparticle–encapsulated messenger RNA (mRNA) formulation of this 10-ISG collection reduced influenza A virus plaque size in samples collected from infected mice when given prophylactically. Moreover, when used collectively and delivered prophylactically, the 10-ISG collection was able to protect hamsters against a lethal SARS-CoV-2 challenge, in contrast with the lack of efficacy when mRNAs were delivered individually. These findings suggest that these 10 ISGs have potential as a broad-spectrum antiviral prophylactic.
 
Back
Top Bottom