Gelsolin protects mitochondria and regulates inflammation during Legionella pneumophila infection

Verdict. We showed that gelsolin knockout (gsn-/-) mice succumb more quickly to severe L. pneumophila infection despite no difference in bacterial loads in the lung compared to wild type mice. It intersects mitochondrial stress/dysfunction themes (cell death; disease context; inflammation).

What the authors report

Legionella pneumophila (L. pneumophila) is the causative agent of Legionnaires' disease, a severe bacterial pneumonia. Difficulty in diagnosing Legionnaires' disease leads to an underreporting of cases and delayed treatment.

Key results stated in the abstract include the following. We showed that gelsolin knockout (gsn-/-) mice succumb more quickly to severe L. pneumophila infection despite no difference in bacterial loads in the lung compared to wild type mice. There is an increase in CXCL1/KC production from macrophages from gsn-/- mice, which is accompanied by increased neutrophils and apoptosis in their lungs. Neutrophils lacking gelsolin produce fewer neutrophil extracellular traps, and their mitochondrial capacity is diminished in response to L. pneumophila.

Why it matters for mitochondrial biology

Within mitochondrial research, this work maps primarily to apoptosis, immunology, genetics, therapeutics. It is relevant to mitochondrial dysfunction discourse because the abstract invokes cell death, disease context, inflammation. That does not by itself establish a validated disease mechanism; it indicates thematic proximity. Because a therapeutic or interventional angle is present, the piece is of interest for mitochondrial-targeted drug hypothesis generation—subject to full-text validation of endpoints and safety context. Server: biorxiv. Posted 2026-08-20. Synthesis confidence is bounded by abstract completeness.

Study design (abstract-level)

We showed that gelsolin knockout (gsn-/-) mice succumb more quickly to severe L. pneumophila infection despite no difference in bacterial loads in the lung compared to wild type mice. There is an increase in CXCL1/KC production from macrophages from gsn-/- mice, which is accompanied by increased neutrophils and apoptosis in their lungs. When given recombinant gelsolin protein, gsn-/- mice survive significantly longer during severe L. pneumophila infection, with reduced lung pathology, and the inflammatory signature of their macrophages was reduced in vitro.

Principal findings

1. We showed that gelsolin knockout (gsn-/-) mice succumb more quickly to severe L. pneumophila infection despite no difference in bacterial loads in the lung compared to wild type mice.
2. There is an increase in CXCL1/KC production from macrophages from gsn-/- mice, which is accompanied by increased neutrophils and apoptosis in their lungs.
3. Neutrophils lacking gelsolin produce fewer neutrophil extracellular traps, and their mitochondrial capacity is diminished in response to L. pneumophila.
4. When given recombinant gelsolin protein, gsn-/- mice survive significantly longer during severe L. pneumophila infection, with reduced lung pathology, and the inflammatory signature of their macrophages was reduced in vitro.
5. Together, gelsolin protects mice during severe L. pneumophila infection, dampens inflammation, promotes mitochondrial health, and maintains neutrophil function.

Limitations of this brief

• This Mitos brief is an abstract-level synthesis of a preprint; it is not peer review and not a substitute for reading the full paper.
• Preprint status: findings may change with revision or journal review.
• Effect sizes, n numbers, statistics, and full experimental controls are typically incomplete at abstract resolution.
• Evidence appears non-human or in vitro from the abstract; translational claims require independent scrutiny.
• Primary source: biorxiv DOI 10.64898/2026.08.17.745205 (posted 2026-08-20).

Open scientific questions

• Which specific experimental panels in the full paper establish the strongest causal claim, and how robust are the controls?
• Are OXPHOS defects primary drivers or secondary consequences of broader cellular stress?
• What dose, timing, and off-target profile would be required to take the intervention seriously as a therapeutic hypothesis?
• How do these findings sit relative to prior literature on the same pathway—replication, contradiction, or incremental extension?

Bottom line

For mitochondrial biologists focused on apoptosis, immunology, genetics, this preprint is worth full-text review soon. Abstract-level takeaway: We showed that gelsolin knockout (gsn-/-) mice succumb more quickly to severe L. pneumophila infection despite no difference in bacterial loads in the lung compared to wild type mice. Confirm methods, effect sizes, and controls in the full PDF before citing the result as established.

Bibliographic record

Abstract-based editorial synthesis by Mitos. Not peer review.