When the Immune System Remembers Too Well

Trained Immunity, Bioenergetic Congestion, and the Road to Gridlock

For decades, we believed only the adaptive immune system had memory.

Vaccines work because T cells and B cells remember. That was the rule.

But a recent 2025 review in Cell Research by Schlüter and colleagues challenges that assumption. It highlights a powerful concept called trained immunity — the idea that the innate immune system can also develop long-term memory through metabolic and epigenetic reprogramming.

This memory can protect us.

But it can also trap us.

And this is where the concept connects deeply with the framework of Exposure-Related Malnutrition (ERM) and the idea of bioenergetic congestion and gridlock.

What Is Trained Immunity?

The review explains that when innate immune cells (like monocytes and macrophages) encounter infections, stress, or even metabolic triggers, they undergo:

• Metabolic rewiring (shift toward glycolysis, mTOR activation)

• Epigenetic remodeling (long-lasting chromatin changes)

• Bone marrow reprogramming at the level of hematopoietic stem cells

This creates a form of inflammatory memory.

In some cases, this is beneficial:

• Better protection against infections

• Enhanced tumor surveillance

• Faster immune response

This is adaptive training.

But when exposures are chronic — high-fat diets, hyperglycemia, repeated stress, systemic inflammation — the same mechanism becomes maladaptive.

The immune system remains “primed.”

Inflammation lingers.

Resolution weakens.

This is where trained immunity starts to resemble something else.

From Training to Congestion

In the ERM framework, we describe two early states:

1. Bioenergetic Congestion

When exposure load temporarily exceeds recovery capacity, but the system can still resolve.

2. Bioenergetic Gridlock

When persistent exposure overwhelms mitochondrial throughput and resolution capacity becomes chronically constrained.

Now consider what the review shows mechanistically:

• Glycolytic predominance

• mTOR-driven anabolic bias

• Acetyl-CoA–dependent histone acetylation

• Persistent IL-1β tone

• Myeloid skewing in the bone marrow

These features map remarkably well onto congestion and gridlock mechanics.

During acute stress, glycolysis is adaptive — it supports rapid immune activation.

But if oxidative phosphorylation (OXPHOS), NAD⁺ recycling, and redox buffering cannot fully restore balance, the system never truly resolves.

What remains?

An epigenetically stabilized inflammatory state.

That is not just immune memory.

That is metabolic memory.

The Missing Piece: Resolution Capacity

The review beautifully details how immune cells are reprogrammed. But it does not fully address a deeper systems-level question:

What determines whether trained immunity remains adaptive — or becomes pathological?

The answer may lie in resolution capacity.

Resolution requires:

• Mitochondrial oxidative throughput

• NAD⁺ regeneration

• Redox buffering

• Lipid mediator synthesis

• Tissue repair programs

These are energy-expensive processes.

If exposure load exceeds energetic resolution capacity repeatedly, incomplete recovery leaves epigenetic scars.

Over time, those scars stabilize.

The system becomes biased toward survival-mode inflammation.

This is gridlock.

Why This Matters Clinically

The review links trained immunity to:

• Atherosclerosis

• Stroke

• Myocardial infarction

• Autoimmune diseases

• Neurodegeneration

• Cancer progression

• Sepsis complications

In many of these conditions, we see:

• Chronic inflammatory tone

• Myeloid skewing

• Metabolic inflexibility

• Impaired repair

From an ERM perspective, these are downstream manifestations of prolonged exposure exceeding allocation capacity.

Trained immunity provides the cellular mechanism.

ERM provides the systems-level framework.

A Unified Principle

We can now articulate a powerful integrative idea:

When exposure load exceeds resolution capacity, the immune system records the mismatch.

If resolution succeeds, adaptive memory forms.

If resolution repeatedly fails, inflammatory programs stabilize into bioenergetic gridlock.

This helps explain:

• Why intermittent high-fat diet may worsen atherosclerosis more than continuous exposure

• Why hyperglycemia leaves long-lasting inflammatory signatures

• Why stroke or myocardial infarction accelerates systemic aging

• Why comorbidities cluster

The bone marrow remembers.

Translating This Further

If trained immunity represents stabilized inflammatory memory, and gridlock represents constrained resolution capacity, then therapeutic strategy should shift from suppressing inflammation alone to:

1. Restoring Bioenergetic Throughput

• Improve mitochondrial efficiency

• Restore NAD⁺ balance

• Enhance metabolic flexibility

• Reduce substrate congestion

2. Supporting Resolution Pathways

• Promote pro-resolving lipid mediators

• Support redox buffering

• Enhance autophagy and mitophagy

3. Reducing Exposure Oscillation

• Stabilize glycemic variability

• Reduce chronic psychological stress

• Improve sleep

• Reduce inflammatory dietary patterns

4. Targeting Maladaptive Central Training

• Modulate IL-1β / NLRP3 pathways

• Address sympathetic overactivation

• Protect hematopoietic stem cell niches

The goal is not to erase immune memory.

It is to restore the recovery bandwidth.

The Bigger Message

You are not broken.

Your immune system is not “overreacting” randomly.

It may be remembering.

And that memory may reflect years of exposure exceeding your capacity to resolve.

Understanding trained immunity through the lens of congestion and gridlock reframes chronic disease:

Not as isolated organ failure.Not as random inflammation.But as a systems-level failure of energetic resolution.

When we restore resolution capacity, memory can become adaptive again.

And gridlock can begin to clear.

Schlüter, T., van Elsas, Y., Priem, B., Ziogas, A., & Netea, M. G. (2025). Trained immunity: Induction of an inflammatory memory in disease. Cell Research, 35, 792–802. https://doi.org/10.1038/s41422-025-01171-y