The interferon state is not baseline in this disease — it is something a menin inhibitor creates, through endogenous retrovirus induction and MHC class II
also called interferon-stimulated gene state · viral mimicry state · HERV-induced interferon response · MHC class II-high state
Cells can be pushed into an antiviral alarm state by switching on ancient virus sequences buried in our own DNA, and that alarm makes them visible to the immune system. In KMT2A-rearranged leukaemia this alarm is not switched on by default — a menin inhibitor switches it on, and the cells then become much easier for donor T cells to kill after a transplant.
The same thing, for a scientist
The brief asked for an interferon or inflammatory state 'if measured'. The honest answer is that there is almost no literature on a **baseline** interferon state in KMT2A-rearranged leukaemia — a PubMed search for `(MLL OR KMT2A) AND leukemia AND interferon signature` returns **2 records**, neither of which characterises one. What does exist, and is new, is an **induced** interferon state. Fetsch et al. found that beyond disrupting oncogenic KMT2A complexes, **menin inhibition induces class II transactivator and MHC class II expression** in KMT2A-rearranged and NPM1-mutated AML cells in vitro and in vivo, sensitising them to T-cell-mediated elimination after allogeneic transplant in mice and enhancing the graft-versus-leukaemia effect in human xenografts. Mechanistically, **menin inhibition increased expression of multiple human endogenous retroviruses, leading to consecutive interferon-stimulated gene upregulation and enhanced MHC-II expression**. It additionally promoted donor T-cell effector function — TNF-alpha, IFN-gamma, perforin, granzyme A/B, cytolytic activity — and reduced T-cell exhaustion, with menin-KMT2A binding found at genes encoding negative regulators of T-cell activation [E1]. This reframes the drug class: a menin inhibitor is not only a differentiating or cytotoxic agent, it is a **conditional immunotherapy sensitiser**, and the trial design that follows is maintenance after allo-HCT rather than monotherapy in relapse. **THIS CHAIN IS CLASS II ONLY, and the obvious extension to class I is published as FALSE.** Sparbier et al tested viral mimicry for MHC class I in the same drug setting and excluded it: depletion of **STAT1**, of **MDA-5 (IFIH1)** and of **RELA** each failed to impair MHC-I activation after menin targeting, and menin is not bound at the bivalent MHC-I promoters. So menin inhibition reaches class II through HERV and interferon-stimulated genes, and reaches class I by a different, STAT1- and MDA-5-independent route. Do not read this entry as a class I mechanism.
Why viral mimicry is the right frame and what it borrows
Derepression of human endogenous retroviruses producing double-stranded RNA, triggering an interferon response and raising antigen presentation, is the established mechanism of 'viral mimicry' first characterised for DNA methyltransferase inhibitors. E1 places menin inhibition in that class for the first time, in a genotype where the drug is already approved.
The chain is: menin displaced → HERV expression up → interferon-stimulated genes up → CIITA and MHC class II up → T-cell recognition up 1. Each step is a standard, measurable node, and each is a place the chain could be broken in a patient.
Two consequences worth separating. Cell-intrinsic: the leukaemic cell becomes more visible. Cell-extrinsic: donor T cells become more functional, and menin-KMT2A binding was found at genes encoding negative regulators of T-cell activation — meaning the drug acts on the T cell as well as on the blast 1. The second is the more surprising and the less controlled, because menin is expressed in every cell including the graft.
The baseline: an absence with a bounded query
Searched 2026-09-20:
(MLL OR KMT2A) AND leukemia AND interferon signature→ 2 records. Title-checked: one concerns EVI1 in AML creating a chemoresistant and immune-suppressive environment; the other is the LAMP-5 paper (seecell-state-innate-immune-lamp5). Neither characterises a baseline interferon signature in KMT2A-rearranged leukaemia.querytranslationinspected: all three blocks expanded normally, MLL and KMT2A both mapped, interferon expanded through its full synonym set. The 2 is a real count.
So the correct statement for this graph is: no baseline interferon or inflammatory-signature characterisation of KMT2A-rearranged leukaemia has been published, and the interferon state that does exist in this disease is a pharmacologically induced one. That is a genuine gap, given how much of modern leukaemia immunotherapy depends on knowing where a subtype sits on the inflamed-to-cold axis.
What it implies for how these drugs should be sequenced
If menin inhibition raises MHC-II and interferon-stimulated genes and improves donor T-cell function, then its value is context-dependent in a way monotherapy trials cannot measure:
- After allo-HCT, the mechanism has a substrate — donor T cells — and the authors propose exactly that trial.
- Before or without a transplant, in a heavily pretreated lymphopenic infant, there may be no effector population for the induced visibility to matter to.
- Alongside a T-cell engager or CAR product, raised antigen presentation and reduced T-cell exhaustion would be expected to help, and this graph's
hyp-menin-plus-engager-orthogonal-pre-emptionalready proposes such a pairing on other grounds. E1 supplies an independent mechanistic reason. - Alongside immunosuppression, which is standard after allo-HCT for GVHD prophylaxis, the mechanism is directly opposed. That interaction is unaddressed and is the obvious practical obstacle to the trial the paper proposes.
MHC class II upregulation also cuts both ways after transplant: it is the substrate for graft-versus-leukaemia and for graft-versus-host disease, and the paper's own framing is GVL enhancement rather than GVHD-free GVL enhancement.
| state definition | Expression of interferon-stimulated genes with raised antigen-presentation machinery, arising here from derepression of endogenous retroviral elements rather than from exogenous interferon or infection |
|---|---|
| cell extrinsic arm | menin inhibition directly raised donor T-cell TNF-alpha, IFN-gamma, perforin and granzyme A/B and cytolytic activity, reduced T-cell exhaustion, and menin-KMT2A was found bound at genes encoding negative regulators of T-cell activation |
| proposed clinical setting | menin inhibition as maintenance after allogeneic haematopoietic cell transplant |
| unaddressed interaction | post-transplant immunosuppression (calcineurin inhibition, post-transplant cyclophosphamide) suppresses the effector functions this mechanism requires; and the same mechanism is the mechanism of GVHD |
mechanistic chain
[ "menin inhibition displaces menin from KMT2A complexes", "multiple human endogenous retroviruses are expressed", "interferon-stimulated genes are upregulated", "CIITA (class II transactivator) and MHC class II rise", "T-cell-mediated elimination after allo-HCT is enhanced" ]
baseline state
{
"status": "uncharacterised",
"query": "(MLL OR KMT2A) AND leukemia AND interferon signature",
"count": 2,
"date": "2026-09-20",
"querytranslation_checked": true,
"note": "neither record characterises a baseline interferon signature; alias coverage is MLL and KMT2A only, so the count is a floor"
}atlas refs
[
{
"label": "Menin inhibition induces HERV expression, ISGs and MHC-II, enhancing GVL",
"pmid": "41144759",
"title": "Menin inhibition enhances graft-versus-leukemia effects by T-cell activation and endogenous retrovirus induction in AML.",
"authors": "Fetsch V, Schwöbel L, Ozyerli-Goknar E, et al.",
"venue": "Blood",
"year": 2026,
"title_provenance": "Title/authors/venue backfilled from PubMed esummary on 2026-09-20 because this citation stored a bare PMID with no title, which made it unscoreable by verify-citations.py. BACKFILLING IS NOT VERIFICATION: it confirms the PMID resolves to a real paper, not that this is the right paper for the claim. That still requires reading."
},
{
"label": "LAMP-5 as a regulator holding type-1 interferon signalling down in MLL-r leukaemia",
"pmid": "33910331",
"title": "LAMP-5 is an essential inflammatory-signaling regulator and novel immunotherapy target for mixed lineage leukemia-rearranged acute leukemia.",
"authors": "Gracia-Maldonado G, Clark J, Burwinkel M, et al.",
"venue": "Haematologica",
"year": 2022,
"title_provenance": "Title/authors/venue backfilled from PubMed esummary on 2026-09-20 because this citation stored a bare PMID with no title, which made it unscoreable by verify-citations.py. BACKFILLING IS NOT VERIFICATION: it confirms the PMID resolves to a real paper, not that this is the right paper for the claim. That still requires reading."
}
]- The mechanism that makes leukaemia visible to donor T cells is the mechanism that makes healthy tissue visible to them; enhanced GVL through raised MHC-II and donor T-cell effector function has no published separation from enhanced GVHD.
- The proposed setting is maintenance after allogeneic transplant, which is precisely when patients are receiving drugs designed to suppress the T-cell functions this mechanism depends on.
- Interferon and HERV induction in an infant is not the same intervention as in an adult: the developing immune system is being trained during the same period, and chronic interferon-stimulated gene activation has developmental consequences no oncology trial measures.
- If the effect requires a donor T-cell compartment, then the large population of children who do not proceed to transplant gains nothing from this mechanism, and a trial that enrols them will dilute the effect it was designed to detect.
- Does menin inhibition induce HERVs and interferon-stimulated genes in KMT2A-rearranged ALL as it does in AML? The lymphoid disease is where infants are, MHC class II biology differs between B-lineage and myeloid cells, and B-lymphoblasts are constitutively MHC-II-positive — so the whole mechanism may be saturated or absent there.
- Is the MHC class II induction a lineage artefact? KMT2A-rearranged AML lines are monocytic-enriched and monocytic cells express MHC-II constitutively; an isogenic or lineage-matched control would settle whether the induction is fusion-related.
- Does the GVL benefit survive standard post-transplant immunosuppression? The proposed trial gives a T-cell-activating drug to patients on T-cell-suppressing drugs, and no published experiment models that combination.
- Does menin inhibition increase GVHD? Every effector function reported as enhancing GVL is also a GVHD effector function, and no GVHD endpoint is reported.
- What is the baseline inflammatory state of KMT2A-rearranged infant ALL? Nobody has profiled it, and every immunotherapy decision in this disease is currently made without that information.
- E1strong confidence 4 of 5: Replicated in peer-reviewed work by more than one group.paper
Beyond disrupting oncogenic KMT2A complex assembly, menin inhibition induced class II transactivator and MHC class II expression in KMT2A-rearranged and NPM1-mutated AML cells in vitro and in vivo; increased MHC-II sensitised AML cells to T-cell-mediated elimination after allogeneic haematopoietic cell transplant in mice, raised MHC-II on primary human AML cells and enhanced graft-versus-leukaemia in human xenograft models; mechanistically menin inhibition increased expression of multiple human endogenous retroviruses leading to consecutive interferon-stimulated gene upregulation and enhanced MHC-II; and menin inhibition directly promoted donor T-cell effector functions with increased TNF-alpha, interferon-gamma, perforin and granzyme A/B and cytolytic activity, with reduced T-cell exhaustion and with menin-KMT2A binding at genes encoding negative regulators of T-cell activation.
Menin inhibition enhances graft-versus-leukemia effects by T-cell activation and endogenous retrovirus induction in AML · Fetsch V, Schwobel L, Ozyerli-Goknar E, Stell AV, Punta M, Plenge T, et al., Zeiser R · Blood 2026What this evidence cannot show
AML only - KMT2A-rearranged and NPM1-mutated - with no lymphoid arm, so nothing here is established for infant KMT2A-rearranged ALL, the population this graph centres on. MHC class II is constitutively expressed by monocytic cells, and KMT2A-rearranged AML lines are monocytic-enriched; an MHC-II induction measured in that background needs a lineage control that the abstract does not describe. The allogeneic transplant models are murine or xenograft, so the T-cell compartment is either murine or a humanised approximation and neither reproduces post-transplant immunosuppression as given to patients. The direct T-cell effects mean the drug acts on the graft as well as the leukaemia, which is a mechanism with an obvious GVHD counterpart that the abstract does not quantify. Read: abstract only.
Evidence that argues against this (2)
- Enhanced MHC class II expression and improved donor T-cell effector function are the mechanism of graft-versus-leukaemia and also the mechanism of graft-versus-host disease, and the paper reports increased TNF-alpha, interferon-gamma, perforin and granzyme production by donor T cells together with reduced exhaustion - a profile indistinguishable, at the level reported, from one that would worsen GVHD. Post-transplant patients additionally receive calcineurin inhibitors or post-transplant cyclophosphamide, which suppress precisely the effector functions this mechanism requires, so the proposed maintenance trial would deliver the drug into a pharmacologically hostile setting. No GVHD endpoint is reported in the abstract. Read: abstract only (same paper). Fetsch V et al. 2026
- BOUNDS THE MECHANISM RATHER THAN THE RESULT. The HERV -> interferon-stimulated gene -> CIITA chain is established for class II, but the same route was tested for class I and ruled out: neither STAT1 depletion (required for interferon-induced MHC-I) nor MDA-5/IFIH1 depletion (the dsRNA sensor of viral mimicry) impaired MHC-I activation under menin targeting, and RELA was not required either. An entry describing an interferon-driven state invites the extension to class I, and the extension is published as false. Sparbier CE et al. 2023
- E2moderate confidence 3 of 5: One strong study, or several smaller consistent ones.paper
A PubMed search for `(MLL OR KMT2A) AND leukemia AND interferon signature`, run 2026-09-20 with the query translation inspected and all three concept blocks confirmed to expand normally, returns exactly 2 records, neither of which characterises a baseline interferon signature in KMT2A-rearranged leukaemia: one concerns EVI1 promoting a chemoresistant and immune-suppressive environment in AML via ERG and cyclin D1, and the other identifies LAMP-5 as an inflammatory-signalling regulator and immunotherapy target in MLL-rearranged acute leukaemia.
LAMP-5 is an essential inflammatory-signaling regulator and novel immunotherapy target for mixed lineage leukemia-rearranged acute leukemia · Gracia-Maldonado G, Clark J, Burwinkel M, Greenslade B, Wunderlich M, Salomonis N, et al., Lee LH · Haematologica 2022What this evidence cannot show
This is a bounded-absence claim and is only as good as the symbol set: the query uses MLL and KMT2A but not the retired alias ALL-1, not HRX or HTRX, and not the phrase 'mixed lineage leukemia' spelled out, so the true count of records touching interferon biology in this disease is a floor rather than an exact number. 'Interferon signature' is also a specific phrase; a paper measuring interferon-stimulated genes without using that phrase would not be retrieved. The citation attached is one of the two records returned, cited here for its existence and its content, not as the source of the count. Read: abstract only.
Evidence that argues against this (1)
- The absence of a baseline interferon signature in the literature is not evidence that the state does not exist, and one of the two retrieved records points the other way: LAMP-5 depletion in MLL-rearranged leukaemia INHIBITS NF-kB signalling and INCREASES activation of type-1 interferon signalling downstream of Toll-like receptor and IL-1 receptor activation, with LAMP-5 acting to transfer signal flux from interferon-signalling endosomes to pro-inflammatory endosomes. That describes a cell actively holding an interferon response down, which is a baseline interferon-relevant state - it has simply never been profiled as a signature. Read: abstract only (same paper). Gracia-Maldonado G et al. 2022
CONSISTENT: CIITA being menin-unbound is what an indirect HERV/interferon route predicts.
menin inhibition induces multiple human endogenous retroviruses, interferon-stimulated genes, CIITA and MHC class II, enhancing T-cell-mediated elimination after allo-HCT
an immunological arm of the post-menin-release state, additional to differentiation, death and lineage switch
raised antigen presentation and reduced donor T-cell exhaustion give an independent mechanistic reason to pair menin inhibition with a T-cell-directed agent
the baseline the induced state acts against: LAMP-5 actively routes TLR/IL-1R flux away from interferon signalling, and LAMP5 level is an untested modifier of the menin inhibitor's immunological effect
the 2-record interferon count is the weakest absence claim in the beat; alias coverage excludes ALL-1, HRX and HTRX
the class II/HERV route; same drug class, different and explicitly separable mechanism
the transactivator the HERV-interferon route converges on
the HERV/interferon route was tested for class I and excluded: STAT1 and MDA-5 depletion did not impair it
- ← related toCSNK2A1 (casein kinase 2 alpha) - the one kinase that turns up three separate times in KMT2A biology
Csnk2a1-null mouse HSCs remodel toward interferon signalling and antigen presentation with Nfkb1/Rfx5 hubs; NORMAL HSC with no drug and no fusion, so vocabulary is shared with the menin-inhibitor-induced state but provenance is not. Preprint
LRRK2 is IFN-gamma-inducible via ERK5/MAPK7 in monocytes and THP-1; never measured in the menin-inhibitor interferon state
surface class I abundance is the interferon- and menin-inhibitor-responsive variable; cell type is not
the HERV/interferon/MHC-II state this hypothesis argues has no headroom in B-precursor disease
the cell state through which menin inhibition is reported to enhance graft-versus-leukaemia