# Training the Lung, Taming the NETs

**Authors:** Piyush Baindara

PMC · DOI: 10.3389/fcimb.2026.1778635 · Frontiers in Cellular and Infection Microbiology · 2026-02-18

## TL;DR

The paper argues for combining treatments targeting immune mechanisms in the lung to improve outcomes in severe respiratory infections.

## Contribution

Proposes a unified host-directed strategy by co-targeting NET regulation and trained immunity.

## Key findings

- Overactive immune responses, not microbial load, often cause lung failure in severe respiratory infections.
- NETs and trained immunity are interconnected and should be co-targeted in therapies.
- Current treatments focus on pathogens, but host-directed strategies may reduce immunopathology.

## Abstract

Respiratory infections remain a major global health threat, and recent epidemics have shown that treating the pathogen alone is not enough. In severe influenza, COVID-19, RSV, and bacterial pneumonia, lung failure often results less from microbial load and more from the host’s overactive immune response. Two key processes, neutrophil extracellular traps (NETs) and trained immunity, sit at the center of this shift toward host-focused intervention. Although both are innate defenses, they are usually discussed in isolation: NETs in the context of acute inflammation and thrombosis, and trained immunity in the context of vaccines, epigenetic reprogramming, and metabolic adaptation. Yet in the lung, these mechanisms function as interconnected elements of early defense. This editorial argues that effective therapies should no longer treat them as separate phenomena but instead co-target NET regulation and trained-immunity pathways as a unified, host-directed strategy to reduce immunopathology and improve outcomes in severe respiratory infections.

## Linked entities

- **Proteins:** SPINK5 (serine peptidase inhibitor Kazal type 5)
- **Diseases:** influenza (MONDO:0005812), COVID-19 (MONDO:0100096), bacterial pneumonia (MONDO:0004652)

## Full-text entities

- **Genes:** MPO (myeloperoxidase) [NCBI Gene 4353], SPINK5 (serine peptidase inhibitor Kazal type 5) [NCBI Gene 11005] {aka LEKTI, LETKI, NETS, NS, VAKTI}, PADI4 (peptidyl arginine deiminase 4) [NCBI Gene 23569] {aka PAD, PAD4, PADI5, PDI4, PDI5}
- **Diseases:** microvascular occlusion (MESH:D017566), thrombosis (MESH:D013927), neutrophilic (MESH:C564275), COVID-19 (MESH:D000086382), infection (MESH:D007239), cardiovascular and autoimmune diseases (MESH:D002318), bacterial infections (MESH:D001424), chronic (MESH:D002908), tissue injury (MESH:D017695), Respiratory infections (MESH:D012141), inflammation (MESH:D007249), influenza (MESH:D007251), respiratory disease (MESH:D012140), hyperinflammatory lung diseases (MESH:D008171), lung injury (MESH:D055370), cystic fibrosis (MESH:D003550), organ dysfunction (MESH:D009102), hypoxic (MESH:D002534), lung failure (MESH:D012131), bacterial pneumonia (MESH:D018410), pneumonia (MESH:D011014), chronic obstructive lung diseases (MESH:D029424), ARDS (MESH:D012128)
- **Chemicals:** steroids (MESH:D013256), beta-glucan (MESH:D047071), AMPs (MESH:D000089882), polysaccharides (MESH:D011134)
- **Species:** Bacteria Latreille et al. 1825 (Bacteria stick insect, genus) [taxon 629395], Adenoviridae (family) [taxon 10508], Homo sapiens (human, species) [taxon 9606], Bacillus sp. CG (species) [taxon 1196795], Mus musculus (house mouse, species) [taxon 10090], Saccharomyces cerevisiae (baker's yeast, species) [taxon 4932]

## Full text

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## Figures

1 figure with captions in the complete paper: https://tomesphere.com/paper/PMC12957086/full.md

## References

24 references — full list in the complete paper: https://tomesphere.com/paper/PMC12957086/full.md

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Source: https://tomesphere.com/paper/PMC12957086