Mon Sep 09 14:00:00 UTC 2024: ## Neutrophil Pyroptosis: A New Front in the Fight Against Cutaneous Leishmaniasis
**LAUSANNE, SWITZERLAND – September 9, 2024** – A new study published in PLOS Pathogens reveals a critical role for neutrophil pyroptosis in controlling cutaneous leishmaniasis, a neglected tropical disease affecting millions worldwide. Researchers from the University of Lausanne and other institutions discovered that the parasite *Leishmania mexicana* triggers a specific inflammasome pathway in neutrophils, ultimately leading to their programmed cell death and a reduction in parasite burden.
“We found that *L. mexicana* infection activates the NLRP1 inflammasome in neutrophils, leading to caspase-1-dependent activation of Gasdermin D (GSDMD),” explains Dr. Fabienne Tacchini-Cottier, lead author of the study. “This process, called pyroptosis, ultimately leads to the death of the infected neutrophil, effectively controlling the parasite’s initial niche and reducing its ability to spread.”
Previous research has shown that neutrophils can be exploited by *Leishmania* parasites as a “Trojan horse” to enter macrophages, their primary host cells. This study reveals a countermeasure by the host immune system – neutrophil pyroptosis – that actively combats this strategy.
Experiments using mice genetically deficient in GSDMD, specifically in neutrophils, showed exacerbated lesions and increased parasite burden compared to control mice. Adoptive transfer experiments confirmed that the absence of GSDMD-induced pyroptosis resulted in prolonged neutrophil survival and an expanded niche for the parasite.
“This study highlights the importance of neutrophil pyroptosis in controlling *L. mexicana* infection,” says Dr. Tacchini-Cottier. “Our findings suggest that targeting this pathway could be a promising strategy for developing new therapies against cutaneous leishmaniasis.”
The research also revealed that *L. mexicana* can induce pyroptosis in human neutrophils, opening up avenues for investigating the role of this process in human leishmaniasis.
This study adds a new layer of complexity to the host-pathogen interactions in cutaneous leishmaniasis and offers promising new targets for therapeutic intervention. Further research is needed to fully understand the mechanisms of NLRP1 activation in neutrophils and to explore the potential of manipulating this pathway for therapeutic benefit.
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