Mapping the functional form of the trade-off between infection resistance and reproductive fitness under dysregulated immune signaling

PLoS Pathogens, Journal Year: 2024, Volume and Issue: 20(2), P. e1012049 - e1012049

Published: Feb. 26, 2024

Immune responses benefit organismal fitness by clearing parasites but also exact costs associated with immunopathology and energetic investment. Hosts manage these tightly regulating the induction of immune signaling to curtail excessive restore homeostasis. Despite theoretical importance turning off response mitigate costs, experimentally connecting variation in negative regulation remains a frontier evolutionary immunology. In this study, we used dose-response approach manipulate RNAi-mediated knockdown efficiency cactus (IκBα), central regulator Toll pathway signal transduction flour beetles (Tribolium castaneum). By titrating activity across four distinct levels, derived shape relationship between investment traits host fitness, including infection susceptibility, lifespan, fecundity, body mass, gut Cactus knock-down increased overall magnitude inducible delayed their resolution dsRNA dose-dependent manner, promoting survival resistance following bacterial infection. However, benefits were counterbalanced integrity. Our results allowed us move beyond qualitative identification trade-off actually derive its functional form. This paves way quantitatively compare evolution impact regulatory elements on life-history trade-offs filling crucial gap our conceptual models network maintenance natural systems.

Language: Английский

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Chronic bacterial infections exert metabolic costs in Drosophila melanogaster

Journal of Experimental Biology, Journal Year: 2025, Volume and Issue: 228(1)

Published: Jan. 1, 2025

ABSTRACT Bacterial infections can substantially impact host metabolic health as a result of the direct and indirect demands sustaining an immune response nutrient piracy by pathogen itself. Drosophila melanogaster other insects that survive sublethal bacterial infection often carry substantial burdens for remainder life. In this study, we asked whether these chronic exact costs host, how scale with severity infection. We infected D. four species (Providencia rettgeri, Serratia marcescens, Enterococcus faecalis Lactococcus lactis) assayed traits in chronically survivors. found carrying were uniformly more susceptible to starvation than uninfected controls, sensitivity escalated higher burden. observed some evidence greater depletion triglyceride glycogen stores loads, although varied among species. Chronically flies exhibit sustained upregulation response, which hypothesized might contribute costs. Consistent prediction, genetic activation major innate signaling pathways depleted increased even absence These results demonstrate have fitness consequences hosts, arising part from pathogen-induced activation, quantitatively

Language: Английский

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A Trade‐Off Between Antimicrobial Peptide Resistance and Sensitivity to Host Immune Effectors in Staphylococcus aureus In Vivo

Evolutionary Applications, Journal Year: 2025, Volume and Issue: 18(2)

Published: Feb. 1, 2025

ABSTRACT Antimicrobial peptides (AMPs) are essential immune effectors of multicellular organisms. Bacteria can evolve resistance to AMPs. Surprisingly, when used challenge the yellow mealworm beetle, Tenebrio molitor , Staphylococcus aureus resistant an abundant AMP (tenecin 1) very same host species did not increase mortality or bacterial load compared infections with wild‐type S. . A possible explanation is that antimicrobial costly due collaterally increased sensitivity AMP‐resistant strains other effectors. Here, we study a group (resistant tenecin 1 combination + 2) such as phenoloxidase and AMPs in vivo. Using RNAi‐based knockdown, investigate survival insect hosts lacking selected We find all except one strain displayed collateral toward phenoloxidase. Some show components beetle defense cocktail. Our findings consistent idea does translate into changes virulence because it balanced by fails provide net advantage environment dominated

Language: Английский

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Resources Modulate Developmental Shifts but Not Infection Tolerance Upon Co‐Infection in an Insect System

Molecular Ecology, Journal Year: 2025, Volume and Issue: unknown

Published: March 20, 2025

ABSTRACT Energetic resources within organisms fuel both parasite growth and immune responses against them, but it is unclear whether energy allocation sufficient to explain changes in infection outcomes under the threat of multiple parasites. We manipulated diet flour beetles ( Tribolium confusum ) infected with two natural parasites used a combination transcriptomic phenotypic assays investigate role shifting metabolic after single co‐infection. Our results suggest that relatively benign, single‐celled, eukaryotic gregarine alter within‐host energetic environment and, by extension, juvenile development time, diet‐dependent manner. While they do not affect host resistance acute bacterial infection, mRNA‐seq reveal stimulate expression an alternative set genes promote damage gut, ultimately contributing reduced survival regardless diet. Thus, immunological contribution co‐infection outcomes, emphasising importance mechanistic insight for predicting impact across levels biological organisation.

Language: Английский

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Virulence decomposition for bifurcating infections

Proceedings of the Royal Society B Biological Sciences, Journal Year: 2023, Volume and Issue: 290(1998)

Published: May 10, 2023

A fundamental goal in infection biology is to understand the emergence of variation pathogen virulence-here defined as decrease host fitness caused by a pathogen. To uncover sources such variation, virulence can be decomposed into both host- and pathogen-associated components. However, decomposing challenging owing complex within-host dynamics bifurcating infections, which recently received increased empirical theoretical attention. Bifurcating infections are characterized two distinct types: (i) terminal with high loads resulting rapid death, (ii) persistent lower delayed death. Here, we propose use discrete mixture models perform separate decompositions for each type. Using this approach, reanalysed published experimental dataset on bacterial load survival

Language: Английский

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Resources modulate developmental shifts but not infection tolerance upon coinfection in an insect system

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: Aug. 5, 2024

Abstract Energetic resources fuel immune responses and parasite growth within organisms, but it is unclear whether energy allocation sufficient to explain changes in infection outcomes under the threat of multiple parasites. We manipulated diet flour beetles ( Tribolium confusum ) infected with two natural parasites investigate role shifting metabolic after single co-infection. Our results suggest that gregarine alter within-host energetic environment, by extension juvenile development time, a diet- dependent manner. Gregarines do not affect host resistance acute bacterial stimulate expression an alternative set genes promote damage gut, ultimately contributing reduced survival regardless diet. Thus, immunological contribution coinfection outcomes, emphasizing importance mechanistic insight for predicting impact across levels biological organization.

Language: Английский

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