Lepidopteran species have a variety of defence strategies against bacterial infections

Mikonranta, Lauri; Dickel, Franziska; Mappes, Johanna; Freitak, Dalial

doi:10.1016/j.jip.2017.01.012

Cited by 12 publications

(6 citation statements)

References 54 publications

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“…In conclusion, infection is the result of a multifactorial process dependent on both pathogen virulence and host susceptibility. Researchers are becoming increasingly mindful of the differences between entomopathogenic strains [37,38,43,45] and insect hosts [54] in studies of pathogenic interactions between insects and bacteria. Assays should therefore be developed on non-model hosts, such as the new invasive African S .…”

Section: Discussionmentioning

confidence: 99%

Inhibition of Spodoptera frugiperda phenoloxidase activity by the products of the Xenorhabdus rhabduscin gene cluster

et al. 2019

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We evaluated the impact of bacterial rhabduscin synthesis on bacterial virulence and phenoloxidase inhibition in a Spodoptera model. We first showed that the rhabduscin cluster of the entomopathogenic bacterium Xenorhabdus nematophila was not necessary for virulence in the larvae of Spodoptera littoralis and Spodoptera frugiperda . Bacteria with mutations affecting the rhabduscin synthesis cluster (Δ isnAB and Δ GT mutants) were as virulent as the wild-type strain. We then developed an assay for measuring phenoloxidase activity in S . frugiperda and assessed the ability of bacterial culture supernatants to inhibit the insect phenoloxidase. Our findings confirm that the X . nematophila rhabduscin cluster is required for the inhibition of S . frugiperda phenoloxidase activity. The X . nematophila Δ isnAB mutant was unable to inhibit phenoloxidase, whereas Δ GT mutants displayed intermediate levels of phenoloxidase inhibition relative to the wild-type strain. The culture supernatants of Escherichia coli and of two entomopathogenic bacteria, Serratia entomophila and Xenorhabdus poinarii , were unable to inhibit S . frugiperda phenoloxidase activity. Heterologous expression of the X . nematophila rhabduscin cluster in these three strains was sufficient to restore inhibition. Interestingly, we observed pseudogenization of the X . poinarii rhabduscin gene cluster via the insertion of a 120 bp element into the isnA promoter. The inhibition of phenoloxidase activity by X . poinarii culture supernatants was restored by expression of the X . poinarii rhabduscin cluster under the control of an inducible P tet promoter, consistent with recent pseudogenization. This study paves the way for advances in our understanding of the virulence of several entomopathogenic bacteria in non-model insects, such as the new invasive S . frugiperda species in Africa.

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Section: Discussionmentioning

confidence: 99%

Inhibition of Spodoptera frugiperda phenoloxidase activity by the products of the Xenorhabdus rhabduscin gene cluster

et al. 2019

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“…X-tox genes encode immunerelated proteins with imperfectly conserved tandem repeats of defensin-like motifs. In moths, however, they have lost their antimicrobial activity, suggesting they may have some other, yet unknown, function within the systemic immune response (Girard et al, 2008;Destoumieux-Garzón et al, 2009;Mikonranta et al, 2017). Additionally, both bacterial treatments upregulated several different types of antimicrobial peptides (AMPs), suggesting that to fight off the bacteria the larvae deploys a cocktail of different AMPs, that might functionally interact and synergistically attack the bacteria.…”

Section: The Immune Responsementioning

confidence: 99%

Physiological Tradeoffs of Immune Response Differs by Infection Type in Pieris napi

et al. 2021

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Understanding the tradeoffs that result from successful infection responses is central to understanding how life histories evolve. Gaining such insights, however, can be challenging, as they may be pathogen specific and confounded with experimental design. Here, we investigated whether infection from gram positive or negative bacteria results in different physiological tradeoffs, and whether these infections impact life history later in life (post-diapause development), in the butterfly Pieris napi. During the first 24 h after infection (3, 6, 12, and 24 h), after removing effects due to injection, larvae infected with Micrococcus luteus showed a strong suppression of all non-immunity related processes while several types of immune responses were upregulated. In contrast, this tradeoff between homeostasis and immune response was much less pronounced in Escherichia coli infections. These differences were also visible long after infection, via weight loss and slower development, as well as an increased mortality at higher infection levels during later stages of development. Individuals infected with M. luteus, compared to E. coli, had a higher mortality rate, and a lower pupal weight, developmental rate and adult weight. Further, males exhibited a more negative impact of infection than females. Thus, immune responses come at a cost even when the initial infection has been overcome, and these costs are likely to affect later life history parameters with fitness consequences.

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“…Subsequently, various cecropins have been isolated from insects such as the silk moth Bombyx mori , wax moth Galleria mellonella , Chinese oak silkmoth Antheraea pernyi, and Asian swallowtail Papilio xuthus [ 31 , 32 , 33 , 34 ]. Insect cecropins display potent antibacterial, antifungal, anticancer, and anti-septic activities [ 35 , 36 , 37 , 38 , 39 , 40 , 41 ]. We have determined the structure of an insect cecropin, papiliocin, containing a cationic amphipathic α-helix at the N-terminus and hydrophobic C-terminal helix connected by a hinge region, which are critical for bacterial membrane permeabilization as well as LPS interactions [ 42 , 43 ].…”

Section: Introductionmentioning

confidence: 99%

Characterization of the Antimicrobial Activities of Trichoplusia ni Cecropin A as a High-Potency Therapeutic against Colistin-Resistant Escherichia coli

Lee

Kim

et al. 2023

Pharmaceutics

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The spread of colistin-resistant bacteria is a serious threat to public health. As an alternative to traditional antibiotics, antimicrobial peptides (AMPs) show promise against multidrug resistance. In this study, we investigated the activity of the insect AMP Tricoplusia ni cecropin A (T. ni cecropin) against colistin-resistant bacteria. T. ni cecropin exhibited significant antibacterial and antibiofilm activities against colistin-resistant Escherichia coli (ColREC) with low cytotoxicity against mammalian cells in vitro. Results of permeabilization of the ColREC outer membrane as monitored through 1-N-phenylnaphthylamine uptake, scanning electron microscopy, lipopolysaccharide (LPS) neutralization, and LPS-binding interaction revealed that T. ni cecropin manifested antibacterial activity by targeting the outer membrane of E. coli with strong interaction with LPS. T. ni cecropin specifically targeted toll-like receptor 4 (TLR4) and showed anti-inflammatory activities with a significant reduction of inflammatory cytokines in macrophages stimulated with either LPS or ColREC via blockade of TLR4-mediated inflammatory signaling. Moreover, T. ni cecropin exhibited anti-septic effects in an LPS-induced endotoxemia mouse model, confirming its LPS-neutralizing activity, immunosuppressive effect, and recovery of organ damage in vivo. These findings demonstrate that T. ni cecropin exerts strong antimicrobial activities against ColREC and could serve as a foundation for the development of AMP therapeutics.

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Lepidopteran species have a variety of defence strategies against bacterial infections

Cited by 12 publications

References 54 publications

Inhibition of Spodoptera frugiperda phenoloxidase activity by the products of the Xenorhabdus rhabduscin gene cluster

Inhibition of Spodoptera frugiperda phenoloxidase activity by the products of the Xenorhabdus rhabduscin gene cluster

Physiological Tradeoffs of Immune Response Differs by Infection Type in Pieris napi

Characterization of the Antimicrobial Activities of Trichoplusia ni Cecropin A as a High-Potency Therapeutic against Colistin-Resistant Escherichia coli

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