Microbial or endogenous molecular patterns as well as pathogen functional features can activate innate immune systems. Whereas detection of infection by pattern recognition receptors has been investigated in details, sensing of virulence factors activities remains less characterized. In Drosophila, genetic evidences indicate that the serine protease Persephone belongs to a danger pathway activated by abnormal proteolytic activities to induce Toll signaling. However, neither the activation mechanism of this pathway nor its specificity has been determined. Here, we identify a unique region in the pro-domain of Persephone that functions as bait for exogenous proteases independently of their origin, type, or specificity. Cleavage in this bait region constitutes the first step of a sequential activation and licenses the subsequent maturation of Persephone to the endogenous cysteine cathepsin 26-29-p. Our results establish Persephone itself as an immune receptor able to sense a broad range of microbes through virulence factor activities rather than molecular patterns.
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http://dx.doi.org/10.1016/j.molcel.2018.01.029 | DOI Listing |
Proc Natl Acad Sci U S A
January 2025
Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai 200032, China.
Entomopathogenic fungi play a critical role in regulating insect populations, and representative species from the and genera have been developed as eco-friendly biocontrol agents for managing agricultural insect pests. Relative to the advances in understanding antifungal immune responses in , knowledge of how fungi evade insect immune defenses remains limited. In this study, we report the identification and characterization of a virulence-required effector Fkp1 in .
View Article and Find Full Text PDFmBio
August 2024
Research group Genetics of Host-Microbe Interactions, Max Planck Institute for Infection Biology, Berlin, Germany.
Unlabelled: Facultative endosymbiotic bacteria, such as and species, are commonly found in association with insects and can dramatically alter their host physiology. Many endosymbionts are defensive and protect their hosts against parasites or pathogens. Despite the widespread nature of defensive insect symbioses and their importance for the ecology and evolution of insects, the mechanisms of symbiont-mediated host protection remain poorly characterized.
View Article and Find Full Text PDFVirulence
December 2023
Department of Entomology, University of Maryland, College Park, MD, USA.
We used to investigate how differences between species in growth rate and mechanisms of pathogenesis influence the outcome of infection. We found that the most rapid germinators and growers and on fly cuticle were the fastest killers, suggesting that pre-penetration competence is key to success. Virulent strains also induced the largest immune response, which did not depend on profuse growth within hosts as virulent toxin-producing strains only proliferated post-mortem while slow-killing strains that were specialized to other insects grew profusely pre-mortem.
View Article and Find Full Text PDFPLoS Genet
June 2023
Department of Genetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan.
The mechanisms by which the innate immune system senses damage have been extensively explored in multicellular organisms. In Drosophila, various types of tissue damage, including epidermal injury, tumor formation, cell competition, and apoptosis deficiency, induce sterile activation of the Toll pathway, a process that requires the use of extracellular serine protease (SP) cascades. Upon infection, the SP Spätzle (Spz)-processing enzyme (SPE) cleaves and activates the Toll ligand Spz downstream of two paralogous SPs, Hayan and Persephone (Psh).
View Article and Find Full Text PDFVirulence
December 2021
HCEMM-USZ, Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary.
infections are the most prevalent cause of serious human mycoses and are the third most common pathogens isolated from bloodstream infections in hospitalized patients. is a member of the spp., which have a predilection for causing life-threatening disease in neonates and hospitalized pediatric patients.
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