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Zhang J, Shan J, Shi W, Feng T, Sheng Y, Xu Z, Dong Z, Huang J, Chen J. Transcriptomic Insights into Host Metabolism and Immunity Changes after Parasitization by Leptopilina myrica. INSECTS 2024; 15:352. [PMID: 38786908 PMCID: PMC11122121 DOI: 10.3390/insects15050352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Revised: 05/11/2024] [Accepted: 05/12/2024] [Indexed: 05/25/2024]
Abstract
Parasitoids commonly manipulate their host's metabolism and immunity to facilitate their offspring survival, but the mechanisms remain poorly understood. Here, we deconstructed the manipulation strategy of a newly discovered parasitoid wasp, L. myrica, which parasitizes D. melanogaster. Using RNA-seq, we analyzed transcriptomes of L. myrica-parasitized and non-parasitized Drosophila host larvae. A total of 22.29 Gb and 23.85 Gb of clean reads were obtained from the two samples, respectively, and differential expression analysis identified 445 DEGs. Of them, 304 genes were upregulated and 141 genes were downregulated in parasitized hosts compared with non-parasitized larvae. Based on the functional annotations in the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases, we found that the genes involved in host nutrition metabolism were significantly upregulated, particularly in carbohydrate, amino acid, and lipid metabolism. We also identified 30 other metabolism-related DEGs, including hexokinase, fatty acid synthase, and UDP-glycosyltransferase (Ugt) genes. We observed that five Bomanin genes (Boms) and six antimicrobial peptides (AMPs) were upregulated. Moreover, a qRT-PCR analysis of 12 randomly selected DEGs confirmed the reproducibility and accuracy of the RNA-seq data. Our results provide a comprehensive transcriptomic analysis of how L. myrica manipulates its host, laying a solid foundation for studies on the regulatory mechanisms employed by parasitoid wasps in their hosts.
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Affiliation(s)
- Junwei Zhang
- Institute of Insect Sciences, Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insect Pests, Zhejiang University, Hangzhou 310058, China; (J.Z.); (J.S.); (W.S.); (T.F.); (Y.S.); (Z.X.); (Z.D.); (J.H.)
- Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Zhejiang University, Hangzhou 310058, China
| | - Jieyu Shan
- Institute of Insect Sciences, Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insect Pests, Zhejiang University, Hangzhou 310058, China; (J.Z.); (J.S.); (W.S.); (T.F.); (Y.S.); (Z.X.); (Z.D.); (J.H.)
- Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Zhejiang University, Hangzhou 310058, China
| | - Wenqi Shi
- Institute of Insect Sciences, Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insect Pests, Zhejiang University, Hangzhou 310058, China; (J.Z.); (J.S.); (W.S.); (T.F.); (Y.S.); (Z.X.); (Z.D.); (J.H.)
- Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Zhejiang University, Hangzhou 310058, China
| | - Ting Feng
- Institute of Insect Sciences, Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insect Pests, Zhejiang University, Hangzhou 310058, China; (J.Z.); (J.S.); (W.S.); (T.F.); (Y.S.); (Z.X.); (Z.D.); (J.H.)
- Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Zhejiang University, Hangzhou 310058, China
| | - Yifeng Sheng
- Institute of Insect Sciences, Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insect Pests, Zhejiang University, Hangzhou 310058, China; (J.Z.); (J.S.); (W.S.); (T.F.); (Y.S.); (Z.X.); (Z.D.); (J.H.)
- Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Zhejiang University, Hangzhou 310058, China
| | - Zixuan Xu
- Institute of Insect Sciences, Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insect Pests, Zhejiang University, Hangzhou 310058, China; (J.Z.); (J.S.); (W.S.); (T.F.); (Y.S.); (Z.X.); (Z.D.); (J.H.)
- Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Zhejiang University, Hangzhou 310058, China
| | - Zhi Dong
- Institute of Insect Sciences, Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insect Pests, Zhejiang University, Hangzhou 310058, China; (J.Z.); (J.S.); (W.S.); (T.F.); (Y.S.); (Z.X.); (Z.D.); (J.H.)
- Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Zhejiang University, Hangzhou 310058, China
| | - Jianhua Huang
- Institute of Insect Sciences, Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insect Pests, Zhejiang University, Hangzhou 310058, China; (J.Z.); (J.S.); (W.S.); (T.F.); (Y.S.); (Z.X.); (Z.D.); (J.H.)
- Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Zhejiang University, Hangzhou 310058, China
| | - Jiani Chen
- Institute of Insect Sciences, Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insect Pests, Zhejiang University, Hangzhou 310058, China; (J.Z.); (J.S.); (W.S.); (T.F.); (Y.S.); (Z.X.); (Z.D.); (J.H.)
- Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province, Zhejiang University, Hangzhou 310058, China
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2
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Hanson MA. When the microbiome shapes the host: immune evolution implications for infectious disease. Philos Trans R Soc Lond B Biol Sci 2024; 379:20230061. [PMID: 38497259 PMCID: PMC10945400 DOI: 10.1098/rstb.2023.0061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 08/08/2023] [Indexed: 03/19/2024] Open
Abstract
The microbiome includes both 'mutualist' and 'pathogen' microbes, regulated by the same innate immune architecture. A major question has therefore been: how do hosts prevent pathogenic infections while maintaining beneficial microbes? One idea suggests hosts can selectively activate innate immunity upon pathogenic infection, but not mutualist colonization. Another idea posits that hosts can selectively attack pathogens, but not mutualists. Here I review evolutionary principles of microbe recognition and immune activation, and reflect on newly observed immune effector-microbe specificity perhaps supporting the latter idea. Recent work in Drosophila has found a surprising importance for single antimicrobial peptides in combatting specific ecologically relevant microbes. The developing picture suggests these effectors have evolved for this purpose. Other defence responses like reactive oxygen species bursts can also be uniquely effective against specific microbes. Signals in other model systems including nematodes, Hydra, oysters, and mammals, suggest that effector-microbe specificity may be a fundamental principle of host-pathogen interactions. I propose this effector-microbe specificity stems from weaknesses of the microbes themselves: if microbes have intrinsic weaknesses, hosts can evolve effectors that exploit those weaknesses. I define this host-microbe relationship as 'the Achilles principle of immune evolution'. Incorporating this view helps interpret why some host-microbe interactions develop in a coevolutionary framework (e.g. Red Queen dynamics), or as a one-sided evolutionary response. This clarification should be valuable to better understand the principles behind host susceptibilities to infectious diseases. This article is part of the theme issue 'Sculpting the microbiome: how host factors determine and respond to microbial colonization'.
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Affiliation(s)
- Mark A Hanson
- Centre for Ecology and Conservation, University of Exeter, Cornwall, TR10 9FE, UK
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3
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Hixson B, Huot L, Morejon B, Yang X, Nagy P, Michel K, Buchon N. The transcriptional response in mosquitoes distinguishes between fungi and bacteria but not Gram types. BMC Genomics 2024; 25:353. [PMID: 38594632 PMCID: PMC11003161 DOI: 10.1186/s12864-024-10153-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 02/22/2024] [Indexed: 04/11/2024] Open
Abstract
Mosquitoes are prolific vectors of human pathogens, therefore a clear and accurate understanding of the organization of their antimicrobial defenses is crucial for informing the development of transmission control strategies. The canonical infection response in insects, as described in the insect model Drosophila melanogaster, is pathogen type-dependent, with distinct stereotypical responses to Gram-negative bacteria and Gram-positive bacteria/fungi mediated by the activation of the Imd and Toll pathways, respectively. To determine whether this pathogen-specific discrimination is shared by mosquitoes, we used RNAseq to capture the genome-wide transcriptional response of Aedes aegypti and Anopheles gambiae (s.l.) to systemic infection with Gram-negative bacteria, Gram-positive bacteria, yeasts, and filamentous fungi, as well as challenge with heat-killed Gram-negative, Gram-positive, and fungal pathogens. From the resulting data, we found that Ae. aegypti and An. gambiae both mount a core response to all categories of infection, and this response is highly conserved between the two species with respect to both function and orthology. When we compared the transcriptomes of mosquitoes infected with different types of bacteria, we observed that the intensity of the transcriptional response was correlated with both the virulence and growth rate of the infecting pathogen. Exhaustive comparisons of the transcriptomes of Gram-negative-challenged versus Gram-positive-challenged mosquitoes yielded no difference in either species. In Ae. aegypti, however, we identified transcriptional signatures specific to bacterial infection and to fungal infection. The bacterial infection response was dominated by the expression of defensins and cecropins, while the fungal infection response included the disproportionate upregulation of an uncharacterized family of glycine-rich proteins. These signatures were also observed in Ae. aegypti challenged with heat-killed bacteria and fungi, indicating that this species can discriminate between molecular patterns that are specific to bacteria and to fungi.
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Affiliation(s)
- Bretta Hixson
- Cornell Institute of Host-Microbe Interactions and Disease, Department of Entomology, Cornell University, Ithaca, NY, 14853, USA
| | - Louise Huot
- Cornell Institute of Host-Microbe Interactions and Disease, Department of Entomology, Cornell University, Ithaca, NY, 14853, USA
| | - Bianca Morejon
- Division of Biology, Kansas State University, Manhattan, KS, 66506, USA
| | - Xiaowei Yang
- Cornell Institute of Host-Microbe Interactions and Disease, Department of Entomology, Cornell University, Ithaca, NY, 14853, USA
- Current address: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute for Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Peter Nagy
- Cornell Institute of Host-Microbe Interactions and Disease, Department of Entomology, Cornell University, Ithaca, NY, 14853, USA
| | - Kristin Michel
- Division of Biology, Kansas State University, Manhattan, KS, 66506, USA
| | - Nicolas Buchon
- Cornell Institute of Host-Microbe Interactions and Disease, Department of Entomology, Cornell University, Ithaca, NY, 14853, USA.
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Mpamhanga CD, Kounatidis I. The utility of Drosophila melanogaster as a fungal infection model. Front Immunol 2024; 15:1349027. [PMID: 38550600 PMCID: PMC10973011 DOI: 10.3389/fimmu.2024.1349027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Accepted: 02/27/2024] [Indexed: 04/02/2024] Open
Abstract
Invasive fungal diseases have profound effects upon human health and are on increase globally. The World Health Organization (WHO) in 2022 published the fungal priority list calling for improved public health interventions and advance research. Drosophila melanogaster presents an excellent model system to dissect host-pathogen interactions and has been proved valuable to study immunopathogenesis of fungal diseases. In this review we highlight the recent advances in fungal-Drosophila interplay with an emphasis on the recently published WHO's fungal priority list and we focus on available tools and technologies.
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Affiliation(s)
- Chengetai D Mpamhanga
- School of Life Health and Chemical Sciences, The Open University, Milton Keynes, United Kingdom
| | - Ilias Kounatidis
- School of Life Health and Chemical Sciences, The Open University, Milton Keynes, United Kingdom
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5
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Lu M, Wei D, Shang J, Li S, Song S, Luo Y, Tang G, Wang C. Suppression of Drosophila antifungal immunity by a parasite effector via blocking GNBP3 and GNBP-like 3, the dual receptors for β-glucans. Cell Rep 2024; 43:113642. [PMID: 38175756 DOI: 10.1016/j.celrep.2023.113642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 11/14/2023] [Accepted: 12/18/2023] [Indexed: 01/06/2024] Open
Abstract
The tactics used by animal pathogens to combat host immunity are largely unclear. Here, we report the depiction of the virulence-required effector Tge1 deployed by the entomopathogen Metarhizium robertsii to suppress Drosophila antifungal immunity. Tge1 can target both GNBP3 and GNBP-like 3 (GL3), and the latter can bind to β-glucans like GNBP3, whereas the glucan binding by both receptors can be attenuated by Tge1. As opposed to the surveillance GNBP3, GL3 is inducible in Drosophila depending on the Toll pathway via a positive feedback loop mechanism. Losses of GNBP3 and GL3 genes result in the deregulations of protease cascade, Spätzle maturation, and antimicrobial gene expressions in Drosophila upon fungal challenges. Fly survival assays confirm that GL3 plays a more essential role than GNBP3 in combating fungal infections. In addition to evidencing the gene-for-gene interactions between fungi and insects, our data advance insights into Drosophila antifungal immunity.
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Affiliation(s)
- Mengting Lu
- 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
| | - Dongxiang Wei
- 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; CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Junmei Shang
- 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
| | - Shiqin Li
- 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; School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Shuangxiu Song
- 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
| | - Yujuan Luo
- 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; School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Guirong Tang
- 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
| | - Chengshu Wang
- 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; CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing 100049, China; School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China.
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Ahmed OM, Crocker A, Murthy M. Transcriptional profiling of Drosophila male-specific P1 (pC1) neurons. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.07.566045. [PMID: 37986870 PMCID: PMC10659367 DOI: 10.1101/2023.11.07.566045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
In Drosophila melanogaster, the P1 (pC1) cluster of male-specific neurons both integrates sensory cues and drives or modulates behavioral programs such as courtship, in addition to contributing to a social arousal state. The behavioral function of these neurons is linked to the genes they express, which underpin their capacity for synaptic signaling, neuromodulation, and physiology. Yet, P1 (pC1) neurons have not been fully characterized at the transcriptome level. Moreover, it is unknown how the molecular landscape of P1 (pC1) neurons acutely changes after flies engage in social behaviors, where baseline P1 (pC1) neural activity is expected to increase. To address these two gaps, we use single cell-type RNA sequencing to profile and compare the transcriptomes of P1 (pC1) neurons harvested from socially paired versus solitary male flies. Compared to control transcriptome datasets, we find that P1 (pC1) neurons are enriched in 2,665 genes, including those encoding receptors, neuropeptides, and cell-adhesion molecules (dprs/DIPs). Furthermore, courtship is characterized by changes in ~300 genes, including those previously implicated in regulating behavior (e.g. DopEcR, Octβ3R, Fife, kairos, rad). Finally, we identify a suite of genes that link conspecific courtship with the innate immune system. Together, these data serve as a molecular map for future studies of an important set of higher-order and sexually-dimorphic neurons.
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Affiliation(s)
- Osama M Ahmed
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ 08540, USA
- Department of Psychology, University of Washington, Seattle, WA 98105, USA
| | - Amanda Crocker
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ 08540, USA
- Program in Neuroscience, Middlebury College, Middlebury, VT 05753, USA
| | - Mala Murthy
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ 08540, USA
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7
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Smith BR, Patch KB, Gupta A, Knoles EM, Unckless RL. The genetic basis of variation in immune defense against Lysinibacillus fusiformis infection in Drosophila melanogaster. PLoS Pathog 2023; 19:e1010934. [PMID: 37549163 PMCID: PMC10434897 DOI: 10.1371/journal.ppat.1010934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 08/17/2023] [Accepted: 06/29/2023] [Indexed: 08/09/2023] Open
Abstract
The genetic causes of phenotypic variation often differ depending on the population examined, particularly if the populations were founded by relatively small numbers of genotypes. Similarly, the genetic causes of phenotypic variation among similar traits (resistance to different xenobiotic compounds or pathogens) may also be completely different or only partially overlapping. Differences in genetic causes for variation in the same trait among populations suggests context dependence for how selection acts on those traits. Similarities in the genetic causes of variation for different traits, on the other hand, suggests pleiotropy which would also influence how natural selection shapes variation in a trait. We characterized immune defense against a natural Drosophila pathogen, the Gram-positive bacterium Lysinibacillus fusiformis, in three different populations and found almost no overlap in the genetic architecture of variation in survival post infection. However, when comparing our results to a similar experiment with the fungal pathogen, B. bassiana, we found a convincing shared QTL peak for both pathogens. This peak contains the Bomanin cluster of Drosophila immune effectors. Loss of function mutants and RNAi knockdown experiments confirms a role of some of these genes in immune defense against both pathogens. This suggests that natural selection may act on the entire cluster of Bomanin genes (and the linked region under the QTL) or specific peptides for specific pathogens.
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Affiliation(s)
- Brittny R. Smith
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas, United States of America
| | - Kistie B. Patch
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas, United States of America
| | - Anjali Gupta
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas, United States of America
| | - Emma M. Knoles
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas, United States of America
| | - Robert L. Unckless
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas, United States of America
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8
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Cabrera K, Hoard DS, Gibson O, Martinez DI, Wunderlich Z. Drosophila immune priming to Enterococcus faecalis relies on immune tolerance rather than resistance. PLoS Pathog 2023; 19:e1011567. [PMID: 37566589 PMCID: PMC10446173 DOI: 10.1371/journal.ppat.1011567] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 08/23/2023] [Accepted: 07/19/2023] [Indexed: 08/13/2023] Open
Abstract
Innate immune priming increases an organism's survival of a second infection after an initial, non-lethal infection. We used Drosophila melanogaster and an insect-derived strain of Enterococcus faecalis to study transcriptional control of priming. In contrast to other pathogens, the enhanced survival in primed animals does not correlate with decreased E. faecalis load. Further analysis shows that primed organisms tolerate, rather than resist infection. Using RNA-seq of immune tissues, we found many genes were upregulated in only primed flies, suggesting a distinct transcriptional program in response to initial and secondary infections. In contrast, few genes continuously express throughout the experiment or more efficiently re-activate upon reinfection. Priming experiments in immune deficient mutants revealed Imd is largely dispensable for responding to a single infection but needed to fully prime. Together, this indicates the fly's innate immune response is plastic-differing in immune strategy, transcriptional program, and pathway use depending on infection history.
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Affiliation(s)
- Kevin Cabrera
- Department of Developmental and Cell Biology, University of California, Irvine, California, United States of America
- Biological Design Center, Boston University, Boston, Massachusetts, United States of America
| | - Duncan S. Hoard
- Department of Developmental and Cell Biology, University of California, Irvine, California, United States of America
| | - Olivia Gibson
- Department of Biology, Boston University, Boston, Massachusetts, United States of America
| | - Daniel I. Martinez
- Department of Developmental and Cell Biology, University of California, Irvine, California, United States of America
| | - Zeba Wunderlich
- Biological Design Center, Boston University, Boston, Massachusetts, United States of America
- Department of Biology, Boston University, Boston, Massachusetts, United States of America
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9
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Hixson B, Huot L, Morejon B, Yang X, Nagy P, Michel K, Buchon N. The transcriptional response in mosquitoes distinguishes between fungi and bacteria but not Gram types. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.26.550663. [PMID: 37546902 PMCID: PMC10402080 DOI: 10.1101/2023.07.26.550663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
Mosquitoes are prolific vectors of human pathogens; a clear and accurate understanding of the organization of their antimicrobial defenses is crucial for informing the development of transmission control strategies. The canonical infection response in insects, as described in the insect model Drosophila melanogaster , is pathogen type-dependent, with distinct stereotypical responses to Gram-negative bacteria and Gram-positive bacteria/fungi mediated by the activation of the Imd and Toll pathways, respectively. To determine whether this pathogen-specific discrimination is shared by mosquitoes, we used RNAseq to capture the genome-wide transcriptional response of Aedes aegypti and Anopheles gambiae ( s.l. ) to systemic infection with Gram-negative bacteria, Gram-positive bacteria, yeasts, and filamentous fungi, as well as challenge with heat-killed Gram-negative, Gram-positive, and fungal pathogens. From the resulting data, we found that Ae. aegypti and An. gambiae both mount a core response to all categories of infection, and this response is highly conserved between the two species with respect to both function and orthology. When we compared the transcriptomes of mosquitoes infected with different types of bacteria, we observed that the intensity of the transcriptional response was correlated with both the virulence and growth rate of the infecting pathogen. Exhaustive comparisons of the transcriptomes of Gram-negative-challenged versus Gram-positive-challenged mosquitoes yielded no difference in either species. In Ae. aegypti , however, we identified transcriptional signatures specific to bacterial infection and to fungal infection. The bacterial infection response was dominated by the expression of defensins and cecropins, while the fungal infection response included the disproportionate upregulation of an uncharacterized family of glycine-rich proteins. These signatures were also observed in Ae. aegypti challenged with heat-killed bacteria and fungi, indicating that this species can discriminate between molecular patterns that are specific to bacteria and to fungi.
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10
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Hanson MA, Grollmus L, Lemaitre B. Ecology-relevant bacteria drive the evolution of host antimicrobial peptides in Drosophila. Science 2023; 381:eadg5725. [PMID: 37471548 DOI: 10.1126/science.adg5725] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 06/08/2023] [Indexed: 07/22/2023]
Abstract
Antimicrobial peptides are host-encoded immune effectors that combat pathogens and shape the microbiome in plants and animals. However, little is known about how the host antimicrobial peptide repertoire is adapted to its microbiome. Here, we characterized the function and evolution of the Diptericin antimicrobial peptide family of Diptera. Using mutations affecting the two Diptericins (Dpt) of Drosophila melanogaster, we reveal the specific role of DptA for the pathogen Providencia rettgeri and DptB for the gut mutualist Acetobacter. The presence of DptA- or DptB-like genes across Diptera correlates with the presence of Providencia and Acetobacter in their environment. Moreover, DptA- and DptB-like sequences predict host resistance against infection by these bacteria across the genus Drosophila. Our study explains the evolutionary logic behind the bursts of rapid evolution of an antimicrobial peptide family and reveals how the host immune repertoire adapts to changing microbial environments.
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Affiliation(s)
- M A Hanson
- Global Health Institute, School of Life Science, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
- Disease Ecology and Evolution, Biosciences, University of Exeter, Penryn, United Kingdom
| | - L Grollmus
- Global Health Institute, School of Life Science, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - B Lemaitre
- Global Health Institute, School of Life Science, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
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11
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Bland ML. Regulating metabolism to shape immune function: Lessons from Drosophila. Semin Cell Dev Biol 2023; 138:128-141. [PMID: 35440411 PMCID: PMC10617008 DOI: 10.1016/j.semcdb.2022.04.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 02/21/2022] [Accepted: 04/03/2022] [Indexed: 12/14/2022]
Abstract
Infection with pathogenic microbes is a severe threat that hosts manage by activating the innate immune response. In Drosophila melanogaster, the Toll and Imd signaling pathways are activated by pathogen-associated molecular patterns to initiate cellular and humoral immune processes that neutralize and kill invaders. The Toll and Imd signaling pathways operate in organs such as fat body and gut that control host nutrient metabolism, and infections or genetic activation of Toll and Imd signaling also induce wide-ranging changes in host lipid, carbohydrate and protein metabolism. Metabolic regulation by immune signaling can confer resistance to or tolerance of infection, but it can also lead to pathology and susceptibility to infection. These immunometabolic phenotypes are described in this review, as are changes in endocrine signaling and gene regulation that mediate survival during infection. Future work in the field is anticipated to determine key variables such as sex, dietary nutrients, life stage, and pathogen characteristics that modify immunometabolic phenotypes and, importantly, to uncover the mechanisms used by the immune system to regulate metabolism.
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Affiliation(s)
- Michelle L Bland
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA, 22908, United States.
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12
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Huang J, Lou Y, Liu J, Bulet P, Cai C, Ma K, Jiao R, Hoffmann JA, Liégeois S, Li Z, Ferrandon D. A Toll pathway effector protects Drosophila specifically from distinct toxins secreted by a fungus or a bacterium. Proc Natl Acad Sci U S A 2023; 120:e2205140120. [PMID: 36917667 PMCID: PMC10041126 DOI: 10.1073/pnas.2205140120] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 01/09/2023] [Indexed: 03/16/2023] Open
Abstract
The Drosophila systemic immune response against many Gram-positive bacteria and fungi is mediated by the Toll pathway. How Toll-regulated effectors actually fulfill this role remains poorly understood as the known Toll-regulated antimicrobial peptide (AMP) genes are active only against filamentous fungi and not against Gram-positive bacteria or yeasts. Besides AMPs, two families of peptides secreted in response to infectious stimuli that activate the Toll pathway have been identified, namely Bomanins and peptides derived from a polyprotein precursor known as Baramicin A (BaraA). Unexpectedly, the deletion of a cluster of 10 Bomanins phenocopies the Toll mutant phenotype of susceptibility to infections. Here, we demonstrate that BaraA is required specifically in the host defense against Enterococcus faecalis and against the entomopathogenic fungus Metarhizium robertsii, albeit the fungal burden is not altered in BaraA mutants. BaraA protects the fly from the action of distinct toxins secreted by these Gram-positive and fungal pathogens, respectively, Enterocin V and Destruxin A. The injection of Destruxin A leads to the rapid paralysis of flies, whether wild type (WT) or mutant. However, a larger fraction of wild-type than BaraA flies recovers from paralysis within 5 to 10 h. BaraAs' function in protecting the host from the deleterious action of Destruxin is required in glial cells, highlighting a resilience role for the Toll pathway in the nervous system against microbial virulence factors. Thus, in complement to the current paradigm, innate immunity can cope effectively with the effects of toxins secreted by pathogens through the secretion of dedicated peptides, independently of xenobiotics detoxification pathways.
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Affiliation(s)
- Jianqiong Huang
- Sino-French Hoffmann Institute, Guangzhou Medical University, Guangzhou511436, China
| | - Yanyan Lou
- Sino-French Hoffmann Institute, Guangzhou Medical University, Guangzhou511436, China
| | - Jiyong Liu
- Sino-French Hoffmann Institute, Guangzhou Medical University, Guangzhou511436, China
| | - Philippe Bulet
- Université Grenoble Alpes, Institute for Advanced Biosciences, INSERM U1209, CNRS, UMR 5309, 38000Grenoble, France
- Platform BioPark Archamps, 74160Archamps, France
| | - Chuping Cai
- Sino-French Hoffmann Institute, Guangzhou Medical University, Guangzhou511436, China
- Université de Strasbourg, Faculté des Sciences de la Vie, 67000Strasbourg, France
- Modèles Insectes d'Immunité Innée, Unité Propre de Recherche 9022 du CNRS, Institut de Biologie Moléculaire et Cellulaire du CNRS, 67084Strasbourg, France
| | - Kaiyu Ma
- Sino-French Hoffmann Institute, Guangzhou Medical University, Guangzhou511436, China
| | - Renjie Jiao
- Sino-French Hoffmann Institute, Guangzhou Medical University, Guangzhou511436, China
| | - Jules A. Hoffmann
- Sino-French Hoffmann Institute, Guangzhou Medical University, Guangzhou511436, China
- Université de Strasbourg, Faculté des Sciences de la Vie, 67000Strasbourg, France
- Modèles Insectes d'Immunité Innée, Unité Propre de Recherche 9022 du CNRS, Institut de Biologie Moléculaire et Cellulaire du CNRS, 67084Strasbourg, France
- Université de Strasbourg Institute for Advanced Study, 67000Strasbourg, France
| | - Samuel Liégeois
- Sino-French Hoffmann Institute, Guangzhou Medical University, Guangzhou511436, China
- Université de Strasbourg, Faculté des Sciences de la Vie, 67000Strasbourg, France
- Modèles Insectes d'Immunité Innée, Unité Propre de Recherche 9022 du CNRS, Institut de Biologie Moléculaire et Cellulaire du CNRS, 67084Strasbourg, France
| | - Zi Li
- Sino-French Hoffmann Institute, Guangzhou Medical University, Guangzhou511436, China
| | - Dominique Ferrandon
- Sino-French Hoffmann Institute, Guangzhou Medical University, Guangzhou511436, China
- Université de Strasbourg, Faculté des Sciences de la Vie, 67000Strasbourg, France
- Modèles Insectes d'Immunité Innée, Unité Propre de Recherche 9022 du CNRS, Institut de Biologie Moléculaire et Cellulaire du CNRS, 67084Strasbourg, France
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13
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Unraveling the Role of Antimicrobial Peptides in Insects. Int J Mol Sci 2023; 24:ijms24065753. [PMID: 36982826 PMCID: PMC10059942 DOI: 10.3390/ijms24065753] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 03/14/2023] [Accepted: 03/15/2023] [Indexed: 03/19/2023] Open
Abstract
Antimicrobial peptides (AMPs) are short, mainly positively charged, amphipathic molecules. AMPs are important effectors of the immune response in insects with a broad spectrum of antibacterial, antifungal, and antiparasitic activity. In addition to these well-known roles, AMPs exhibit many other, often unobvious, functions in the host. They support insects in the elimination of viral infections. AMPs participate in the regulation of brain-controlled processes, e.g., sleep and non-associative learning. By influencing neuronal health, communication, and activity, they can affect the functioning of the insect nervous system. Expansion of the AMP repertoire and loss of their specificity is connected with the aging process and lifespan of insects. Moreover, AMPs take part in maintaining gut homeostasis, regulating the number of endosymbionts as well as reducing the number of foreign microbiota. In turn, the presence of AMPs in insect venom prevents the spread of infection in social insects, where the prey may be a source of pathogens.
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14
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Owings KG, Chow CY. A Drosophila screen identifies a role for histone methylation in ER stress preconditioning. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.10.532109. [PMID: 36945590 PMCID: PMC10028959 DOI: 10.1101/2023.03.10.532109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/18/2023]
Abstract
Stress preconditioning occurs when transient, sublethal stress events impact an organism's ability to counter future stresses. Although preconditioning effects are often noted in the literature, very little is known about the underlying mechanisms. To model preconditioning, we exposed a panel of genetically diverse Drosophila melanogaster to a sublethal heat shock and measured how well the flies survived subsequent exposure to endoplasmic reticulum (ER) stress. The impact of preconditioning varied with genetic background, ranging from dying half as fast to four and a half times faster with preconditioning compared to no preconditioning. Subsequent association and transcriptional analyses revealed that histone methylation, transcriptional regulation, and immune status are all candidate preconditioning modifier pathways. Strikingly, almost all subunits (7/8) in the Set1/COMPASS complex were identified as candidate modifiers of preconditioning. Functional analysis of Set1 knockdown flies demonstrated that loss of Set1 led to the transcriptional dysregulation of canonical ER stress genes during preconditioning. Based on these analyses, we propose a model of preconditioning in which Set1 helps to establish an interim transcriptional 'memory' of previous stress events, resulting in a preconditioned response to subsequent stress.
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Affiliation(s)
- Katie G. Owings
- Department of Human Genetics, University of Utah, Salt Lake City, Utah, United States of America
| | - Clement Y. Chow
- Department of Human Genetics, University of Utah, Salt Lake City, Utah, United States of America
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15
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Xu R, Lou Y, Tidu A, Bulet P, Heinekamp T, Martin F, Brakhage A, Li Z, Liégeois S, Ferrandon D. The Toll pathway mediates Drosophila resilience to Aspergillus mycotoxins through specific Bomanins. EMBO Rep 2022; 24:e56036. [PMID: 36322050 PMCID: PMC9827548 DOI: 10.15252/embr.202256036] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 10/06/2022] [Accepted: 10/14/2022] [Indexed: 12/28/2022] Open
Abstract
Host defense against infections encompasses both resistance, which targets microorganisms for neutralization or elimination, and resilience/disease tolerance, which allows the host to withstand/tolerate pathogens and repair damages. In Drosophila, the Toll signaling pathway is thought to mediate resistance against fungal infections by regulating the secretion of antimicrobial peptides, potentially including Bomanins. We find that Aspergillus fumigatus kills Drosophila Toll pathway mutants without invasion because its dissemination is blocked by melanization, suggesting a role for Toll in host defense distinct from resistance. We report that mutants affecting the Toll pathway or the 55C Bomanin locus are susceptible to the injection of two Aspergillus mycotoxins, restrictocin and verruculogen. The vulnerability of 55C deletion mutants to these mycotoxins is rescued by the overexpression of Bomanins specific to each challenge. Mechanistically, flies in which BomS6 is expressed in the nervous system exhibit an enhanced recovery from the tremors induced by injected verruculogen and display improved survival. Thus, innate immunity also protects the host against the action of microbial toxins through secreted peptides and thereby increases its resilience to infection.
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Affiliation(s)
- Rui Xu
- Sino‐French Hoffmann InstituteGuangzhou Medical UniversityGuangzhouChina,Université de StrasbourgStrasbourgFrance,Modèles Insectes de l'Immunité InnéeUPR 9022 du CNRSStrasbourgFrance
| | - Yanyan Lou
- Sino‐French Hoffmann InstituteGuangzhou Medical UniversityGuangzhouChina,Université de StrasbourgStrasbourgFrance,Modèles Insectes de l'Immunité InnéeUPR 9022 du CNRSStrasbourgFrance
| | - Antonin Tidu
- Université de StrasbourgStrasbourgFrance,Architecture et Réactivité de l'ARNUPR 9002 du CNRSStrasbourgFrance
| | - Philippe Bulet
- CR Université Grenoble Alpes, Institute for Advanced Biosciences, Inserm U1209CNRS UMR 5309GrenobleFrance,Platform BioPark ArchampsArchampsFrance
| | - Thorsten Heinekamp
- Department of Molecular and Applied MicrobiologyLeibniz Institute for Natural Product Research and Infection Biology ‐ Hans Knöll Institute (Leibniz‐HKI)JenaGermany
| | - Franck Martin
- Université de StrasbourgStrasbourgFrance,Architecture et Réactivité de l'ARNUPR 9002 du CNRSStrasbourgFrance
| | - Axel Brakhage
- Department of Molecular and Applied MicrobiologyLeibniz Institute for Natural Product Research and Infection Biology ‐ Hans Knöll Institute (Leibniz‐HKI)JenaGermany,Institute of MicrobiologyFriedrich Schiller University JenaJenaGermany
| | - Zi Li
- Sino‐French Hoffmann InstituteGuangzhou Medical UniversityGuangzhouChina
| | - Samuel Liégeois
- Sino‐French Hoffmann InstituteGuangzhou Medical UniversityGuangzhouChina,Université de StrasbourgStrasbourgFrance,Modèles Insectes de l'Immunité InnéeUPR 9022 du CNRSStrasbourgFrance
| | - Dominique Ferrandon
- Sino‐French Hoffmann InstituteGuangzhou Medical UniversityGuangzhouChina,Université de StrasbourgStrasbourgFrance,Modèles Insectes de l'Immunité InnéeUPR 9022 du CNRSStrasbourgFrance
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16
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Shen JL, Doherty J, Allen E, Fortier TM, Baehrecke EH. Atg6 promotes organismal health by suppression of cell stress and inflammation. Cell Death Differ 2022; 29:2275-2287. [PMID: 35523956 PMCID: PMC9614006 DOI: 10.1038/s41418-022-01014-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 04/25/2022] [Accepted: 04/26/2022] [Indexed: 11/08/2022] Open
Abstract
Autophagy targets cytoplasmic materials for degradation, and influences cell health. Alterations in Atg6/Beclin-1, a key regulator of autophagy, are associated with multiple diseases. While the role of Atg6 in autophagy regulation is heavily studied, the role of Atg6 in organism health and disease progression remains poorly understood. Here, we discover that loss of Atg6 in Drosophila results in various alterations to stress, metabolic and immune signaling pathways. We find that the increased levels of circulating blood cells and tumor-like masses in atg6 mutants vary depending on tissue-specific function of Atg6, with contributions from intestine and hematopoietic cells. These phenotypes are suppressed by decreased function of macrophage and inflammatory response receptors crq and drpr. Thus, these findings provide a basis for understanding how Atg6 systemically regulates cell health within multiple organs, and highlight the importance of Atg6 in inflammation to organismal health.
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Affiliation(s)
- James L Shen
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA
| | - Johnna Doherty
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA
| | - Elizabeth Allen
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA
| | - Tina M Fortier
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA
| | - Eric H Baehrecke
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Chan Medical School, Worcester, MA 01605, USA.
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17
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HP1a-mediated heterochromatin formation promotes antimicrobial responses against Pseudomonas aeruginosa infection. BMC Biol 2022; 20:234. [PMID: 36266682 PMCID: PMC9583553 DOI: 10.1186/s12915-022-01435-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 10/10/2022] [Indexed: 11/23/2022] Open
Abstract
Background Pseudomonas aeruginosa is a Gram-negative bacterium that causes severe infectious disease in diverse host organisms, including humans. Effective therapeutic options for P. aeruginosa infection are limited due to increasing multidrug resistance and it is therefore critical to understand the regulation of host innate immune responses to guide development of effective therapeutic options. The epigenetic mechanisms by which hosts regulate their antimicrobial responses against P. aeruginosa infection remain unclear. Here, we used Drosophila melanogaster to investigate the role of heterochromatin protein 1a (HP1a), a key epigenetic regulator, and its mediation of heterochromatin formation in antimicrobial responses against PA14, a highly virulent P. aeruginosa strain. Results Animals with decreased heterochromatin levels showed less resistance to P. aeruginosa infection. In contrast, flies with increased heterochromatin formation, either in the whole organism or specifically in the fat body—an organ important in humoral immune response—showed greater resistance to P. aeruginosa infection, as demonstrated by increased host survival and reduced bacterial load. Increased heterochromatin formation in the fat body promoted the antimicrobial responses via upregulation of fat body immune deficiency (imd) pathway-mediated antimicrobial peptides (AMPs) before and in the middle stage of P. aeruginosa infection. The fat body AMPs were required to elicit HP1a-mediated antimicrobial responses against P. aeruginosa infection. Moreover, the levels of heterochromatin in the fat body were downregulated in the early stage, but upregulated in the middle stage, of P. aeruginosa infection. Conclusions These data indicate that HP1a-mediated heterochromatin formation in the fat body promotes antimicrobial responses by epigenetically upregulating AMPs of the imd pathway. Our study provides novel molecular, cellular, and organismal insights into new epigenetic strategies targeting heterochromatin that have the potential to combat P. aeruginosa infection. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-022-01435-8.
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18
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Hanson MA, Kondo S, Lemaitre B. Drosophila immunity: the Drosocin gene encodes two host defence peptides with pathogen-specific roles. Proc Biol Sci 2022; 289:20220773. [PMID: 35730150 PMCID: PMC9233930 DOI: 10.1098/rspb.2022.0773] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Antimicrobial peptides (AMPs) are key to defence against infection in plants and animals. Use of AMP mutations in Drosophila has now revealed that AMPs can additively or synergistically contribute to defence in vivo. However, these studies also revealed high specificity, wherein just one AMP contributes an outsized role in combatting a specific pathogen. Here, we show the Drosocin locus (CG10816) is more complex than previously described. In addition to its namesake peptide 'Drosocin', it encodes a second mature peptide from a precursor via furin cleavage. This peptide corresponds to the previously uncharacterized 'Immune-induced Molecule 7'. A polymorphism (Thr52Ala) in the Drosocin precursor protein previously masked the identification of this peptide, which we name 'Buletin'. Using mutations differently affecting Drosocin and Buletin, we show that only Drosocin contributes to Drosocin gene-mediated defence against Enterobacter cloacae. Strikingly, we observed that Buletin, but not Drosocin, contributes to the Drosocin gene-mediated defence against Providencia burhodogranariea, including an importance of the Thr52Ala polymorphism for survival. Our study reveals that the Drosocin gene encodes two prominent host defence peptides with different specificity against distinct pathogens. This finding emphasizes the complexity of the Drosophila humoral response and demonstrates how natural polymorphisms can affect host susceptibility.
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Affiliation(s)
- M. A. Hanson
- Global Health Institute, School of Life Science, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - S. Kondo
- Invertebrate Genetics Laboratory, Genetic Strains Research Center, National Institute of Genetics, Mishima, Japan
| | - B. Lemaitre
- Global Health Institute, School of Life Science, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
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19
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Carboni AL, Hanson MA, Lindsay SA, Wasserman SA, Lemaitre B. Cecropins contribute to Drosophila host defense against a subset of fungal and Gram-negative bacterial infection. Genetics 2022; 220:iyab188. [PMID: 34791204 PMCID: PMC8733632 DOI: 10.1093/genetics/iyab188] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 10/15/2021] [Indexed: 11/14/2022] Open
Abstract
Cecropins are small helical secreted peptides with antimicrobial activity that are widely distributed among insects. Genes encoding Cecropins are strongly induced upon infection, pointing to their role in host defense. In Drosophila, four cecropin genes clustered in the genome (CecA1, CecA2, CecB, and CecC) are expressed upon infection downstream of the Toll and Imd pathways. In this study, we generated a short deletion ΔCecA-C removing the whole cecropin locus. Using the ΔCecA-C deficiency alone or in combination with other antimicrobial peptide (AMP) mutations, we addressed the function of Cecropins in the systemic immune response. ΔCecA-C flies were viable and resisted challenge with various microbes as wild-type. However, removing ΔCecA-C in flies already lacking 10 other AMP genes revealed a role for Cecropins in defense against Gram-negative bacteria and fungi. Measurements of pathogen loads confirm that Cecropins contribute to the control of certain Gram-negative bacteria, notably Enterobacter cloacae and Providencia heimbachae. Collectively, our work provides the first genetic demonstration of a role for Cecropins in insect host defense and confirms their in vivo activity primarily against Gram-negative bacteria and fungi. Generation of a fly line (ΔAMP14) that lacks 14 immune inducible AMPs provides a powerful tool to address the function of these immune effectors in host-pathogen interactions and beyond.
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Affiliation(s)
- Alexia L Carboni
- Global Health Institute, School of Life Science, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Mark A Hanson
- Global Health Institute, School of Life Science, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Scott A Lindsay
- Division of Biological Sciences, University of California San Diego (UCSD), La Jolla, CA 92093, USA
| | - Steven A Wasserman
- Division of Biological Sciences, University of California San Diego (UCSD), La Jolla, CA 92093, USA
| | - Bruno Lemaitre
- Global Health Institute, School of Life Science, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
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20
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The Drosophila Baramicin polypeptide gene protects against fungal infection. PLoS Pathog 2021; 17:e1009846. [PMID: 34432851 PMCID: PMC8423362 DOI: 10.1371/journal.ppat.1009846] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 09/07/2021] [Accepted: 07/28/2021] [Indexed: 11/19/2022] Open
Abstract
The fruit fly Drosophila melanogaster combats microbial infection by producing a battery of effector peptides that are secreted into the haemolymph. Technical difficulties prevented the investigation of these short effector genes until the recent advent of the CRISPR/CAS era. As a consequence, many putative immune effectors remain to be formally described, and exactly how each of these effectors contribute to survival is not well characterized. Here we describe a novel Drosophila antifungal peptide gene that we name Baramicin A. We show that BaraA encodes a precursor protein cleaved into multiple peptides via furin cleavage sites. BaraA is strongly immune-induced in the fat body downstream of the Toll pathway, but also exhibits expression in other tissues. Importantly, we show that flies lacking BaraA are viable but susceptible to the entomopathogenic fungus Beauveria bassiana. Consistent with BaraA being directly antimicrobial, overexpression of BaraA promotes resistance to fungi and the IM10-like peptides produced by BaraA synergistically inhibit growth of fungi in vitro when combined with a membrane-disrupting antifungal. Surprisingly, BaraA mutant males but not females display an erect wing phenotype upon infection. Here, we characterize a new antifungal immune effector downstream of Toll signalling, and show it is a key contributor to the Drosophila antimicrobial response.
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21
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Schlamp F, Delbare SYN, Early AM, Wells MT, Basu S, Clark AG. Dense time-course gene expression profiling of the Drosophila melanogaster innate immune response. BMC Genomics 2021; 22:304. [PMID: 33902461 PMCID: PMC8074482 DOI: 10.1186/s12864-021-07593-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 04/09/2021] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Immune responses need to be initiated rapidly, and maintained as needed, to prevent establishment and growth of infections. At the same time, resources need to be balanced with other physiological processes. On the level of transcription, studies have shown that this balancing act is reflected in tight control of the initiation kinetics and shutdown dynamics of specific immune genes. RESULTS To investigate genome-wide expression dynamics and trade-offs after infection at a high temporal resolution, we performed an RNA-seq time course on D. melanogaster with 20 time points post Imd stimulation. A combination of methods, including spline fitting, cluster analysis, and Granger causality inference, allowed detailed dissection of expression profiles, lead-lag interactions, and functional annotation of genes through guilt-by-association. We identified Imd-responsive genes and co-expressed, less well characterized genes, with an immediate-early response and sustained up-regulation up to 5 days after stimulation. In contrast, stress response and Toll-responsive genes, among which were Bomanins, demonstrated early and transient responses. We further observed a strong trade-off with metabolic genes, which strikingly recovered to pre-infection levels before the immune response was fully resolved. CONCLUSIONS This high-dimensional dataset enabled the comprehensive study of immune response dynamics through the parallel application of multiple temporal data analysis methods. The well annotated data set should also serve as a useful resource for further investigation of the D. melanogaster innate immune response, and for the development of methods for analysis of a post-stress transcriptional response time-series at whole-genome scale.
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Affiliation(s)
- Florencia Schlamp
- Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA.
| | | | - Angela M Early
- Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
| | - Martin T Wells
- Statistics and Data Science, Cornell University, Ithaca, NY, USA
| | - Sumanta Basu
- Statistics and Data Science, Cornell University, Ithaca, NY, USA.
| | - Andrew G Clark
- Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA.
- Statistics and Data Science, Cornell University, Ithaca, NY, USA.
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22
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Huang C, Xu R, Liégeois S, Chen D, Li Z, Ferrandon D. Differential Requirements for Mediator Complex Subunits in Drosophila melanogaster Host Defense Against Fungal and Bacterial Pathogens. Front Immunol 2021; 11:478958. [PMID: 33746938 PMCID: PMC7977287 DOI: 10.3389/fimmu.2020.478958] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 12/29/2020] [Indexed: 01/08/2023] Open
Abstract
The humoral immune response to bacterial or fungal infections in Drosophila relies largely on a transcriptional response mediated by the Toll and Immune deficiency NF-κB pathways. Antimicrobial peptides are potent effectors of these pathways and allow the organism to attack invading pathogens. Dorsal-related Immune Factor (DIF), a transcription factor regulated by the Toll pathway, is required in the host defense against fungal and some Gram-positive bacterial infections. The Mediator complex is involved in the initiation of transcription of most RNA polymerase B (PolB)-dependent genes by forming a functional bridge between transcription factors bound to enhancer regions and the gene promoter region and then recruiting the PolB pre-initiation complex. Mediator is formed by several modules that each comprises several subunits. The Med17 subunit of the head module of Mediator has been shown to be required for the expression of Drosomycin, which encodes a potent antifungal peptide, by binding to DIF. Thus, Mediator is expected to mediate the host defense against pathogens controlled by the Toll pathway-dependent innate immune response. Here, we first focus on the Med31 subunit of the middle module of Mediator and find that it is required in host defense against Aspergillus fumigatus, Enterococcus faecalis, and injected but not topically-applied Metarhizium robertsii. Thus, host defense against M. robertsii requires Dif but not necessarily Med31 in the two distinct infection models. The induction of some Toll-pathway-dependent genes is decreased after a challenge of Med31 RNAi-silenced flies with either A. fumigatus or E. faecalis, while these flies exhibit normal phagocytosis and melanization. We have further tested most Mediator subunits using RNAi by monitoring their survival after challenges to several other microbial infections known to be fought off through DIF. We report that the host defense against specific pathogens involves a distinct set of Mediator subunits with only one subunit for C. glabrata or Erwinia carotovora carotovora, at least one for M. robertsii or a somewhat extended repertoire for A. fumigatus (at least eight subunits) and E. faecalis (eight subunits), with two subunits, Med6 and Med11 being required only against A. fumigatus. Med31 but not Med17 is required in fighting off injected M. robertsii conidia. Thus, the involvement of Mediator in Drosophila innate immunity is more complex than expected.
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Affiliation(s)
- Chuqin Huang
- Sino-French Hoffman Institute, Guangzhou Medical University, Guangzhou, China
| | - Rui Xu
- Sino-French Hoffman Institute, Guangzhou Medical University, Guangzhou, China
- Université de Strasbourg, UPR 9022 du CNRS, Strasbourg, France
| | - Samuel Liégeois
- Sino-French Hoffman Institute, Guangzhou Medical University, Guangzhou, China
- Université de Strasbourg, UPR 9022 du CNRS, Strasbourg, France
| | - Di Chen
- Sino-French Hoffman Institute, Guangzhou Medical University, Guangzhou, China
| | - Zi Li
- Sino-French Hoffman Institute, Guangzhou Medical University, Guangzhou, China
| | - Dominique Ferrandon
- Sino-French Hoffman Institute, Guangzhou Medical University, Guangzhou, China
- Université de Strasbourg, UPR 9022 du CNRS, Strasbourg, France
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23
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Martínez BA, Hoyle RG, Yeudall S, Granade ME, Harris TE, Castle JD, Leitinger N, Bland ML. Innate immune signaling in Drosophila shifts anabolic lipid metabolism from triglyceride storage to phospholipid synthesis to support immune function. PLoS Genet 2020; 16:e1009192. [PMID: 33227003 PMCID: PMC7721134 DOI: 10.1371/journal.pgen.1009192] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 12/07/2020] [Accepted: 10/13/2020] [Indexed: 02/07/2023] Open
Abstract
During infection, cellular resources are allocated toward the metabolically-demanding processes of synthesizing and secreting effector proteins that neutralize and kill invading pathogens. In Drosophila, these effectors are antimicrobial peptides (AMPs) that are produced in the fat body, an organ that also serves as a major lipid storage depot. Here we asked how activation of Toll signaling in the larval fat body perturbs lipid homeostasis to understand how cells meet the metabolic demands of the immune response. We find that genetic or physiological activation of fat body Toll signaling leads to a tissue-autonomous reduction in triglyceride storage that is paralleled by decreased transcript levels of the DGAT homolog midway, which carries out the final step of triglyceride synthesis. In contrast, Kennedy pathway enzymes that synthesize membrane phospholipids are induced. Mass spectrometry analysis revealed elevated levels of major phosphatidylcholine and phosphatidylethanolamine species in fat bodies with active Toll signaling. The ER stress mediator Xbp1 contributed to the Toll-dependent induction of Kennedy pathway enzymes, which was blunted by deleting AMP genes, thereby reducing secretory demand elicited by Toll activation. Consistent with ER stress induction, ER volume is expanded in fat body cells with active Toll signaling, as determined by transmission electron microscopy. A major functional consequence of reduced Kennedy pathway induction is an impaired immune response to bacterial infection. Our results establish that Toll signaling induces a shift in anabolic lipid metabolism to favor phospholipid synthesis and ER expansion that may serve the immediate demand for AMP synthesis and secretion but with the long-term consequence of insufficient nutrient storage.
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Affiliation(s)
- Brittany A. Martínez
- Biomedical Sciences Graduate Program, University of Virginia, Charlottesville, VA, United States of America
- Department of Pharmacology, University of Virginia, Charlottesville, VA, United States of America
| | - Rosalie G. Hoyle
- Department of Pharmacology, University of Virginia, Charlottesville, VA, United States of America
| | - Scott Yeudall
- Department of Pharmacology, University of Virginia, Charlottesville, VA, United States of America
- Medical Scientist Training Program, University of Virginia, Charlottesville, VA, United States of America
| | - Mitchell E. Granade
- Biomedical Sciences Graduate Program, University of Virginia, Charlottesville, VA, United States of America
- Department of Pharmacology, University of Virginia, Charlottesville, VA, United States of America
| | - Thurl E. Harris
- Biomedical Sciences Graduate Program, University of Virginia, Charlottesville, VA, United States of America
- Department of Pharmacology, University of Virginia, Charlottesville, VA, United States of America
| | - J. David Castle
- Department of Cell Biology, University of Virginia, Charlottesville, VA, United States of America
| | - Norbert Leitinger
- Biomedical Sciences Graduate Program, University of Virginia, Charlottesville, VA, United States of America
- Department of Pharmacology, University of Virginia, Charlottesville, VA, United States of America
| | - Michelle L. Bland
- Biomedical Sciences Graduate Program, University of Virginia, Charlottesville, VA, United States of America
- Department of Pharmacology, University of Virginia, Charlottesville, VA, United States of America
- * E-mail:
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24
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Feng M, Fei S, Xia J, Labropoulou V, Swevers L, Sun J. Antimicrobial Peptides as Potential Antiviral Factors in Insect Antiviral Immune Response. Front Immunol 2020; 11:2030. [PMID: 32983149 PMCID: PMC7492552 DOI: 10.3389/fimmu.2020.02030] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 07/27/2020] [Indexed: 12/17/2022] Open
Abstract
Antimicrobial peptides (AMPs) with antiviral activity (antiviral peptides: AVPs) have become a research hotspot and already show immense potential to become pharmaceutically available antiviral drugs. AVPs have exhibited huge potential in inhibiting viruses by targeting various stages of their life cycle. Insects are the most speciose group of animals that inhabit almost all ecosystems and habitats on the land and are a rich source of natural AMPs. However, insect AVP mining, functional research, and drug development are still in their infancy. This review aims to summarize the currently validated insect AVPs, explore potential new insect AVPs and to discuss their possible mechanism of synthesis and action, with a view to providing clues to unravel the mechanisms of insect antiviral immunity and to develop insect AVP-derived antiviral drugs.
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Affiliation(s)
- Min Feng
- Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou, China.,Insect Molecular Genetics and Biotechnology, Institute of Biosciences and Applications, National Centre for Scientific Research Demokritos, Athens, Greece
| | - Shigang Fei
- Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Junming Xia
- Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Vassiliki Labropoulou
- Insect Molecular Genetics and Biotechnology, Institute of Biosciences and Applications, National Centre for Scientific Research Demokritos, Athens, Greece
| | - Luc Swevers
- Insect Molecular Genetics and Biotechnology, Institute of Biosciences and Applications, National Centre for Scientific Research Demokritos, Athens, Greece
| | - Jingchen Sun
- Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou, China
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25
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Lin SJH, Cohen LB, Wasserman SA. Effector specificity and function in Drosophila innate immunity: Getting AMPed and dropping Boms. PLoS Pathog 2020; 16:e1008480. [PMID: 32463841 PMCID: PMC7255597 DOI: 10.1371/journal.ppat.1008480] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- Samuel J. H. Lin
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, California, United States of America
| | - Lianne B. Cohen
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, California, United States of America
| | - Steven A. Wasserman
- Section of Cell and Developmental Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, California, United States of America
- * E-mail:
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26
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Valanne S, Järvelä-Stölting M, Harjula SKE, Myllymäki H, Salminen TS, Rämet M. Osa-Containing Brahma Complex Regulates Innate Immunity and the Expression of Metabolic Genes in Drosophila. THE JOURNAL OF IMMUNOLOGY 2020; 204:2143-2155. [PMID: 32198143 DOI: 10.4049/jimmunol.1900571] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 02/12/2020] [Indexed: 01/20/2023]
Abstract
Negative regulation of innate immunity is essential to avoid autoinflammation. In Drosophila melanogaster, NF-κB signaling-mediated immune responses are negatively regulated at multiple levels. Using a Drosophila RNA interference in vitro screen, we identified a set of genes inhibiting immune activation. Four of these genes encode members of the chromatin remodeling Osa-containing Brahma (BAP) complex. Silencing additional two genes of the BAP complex was shown to have the same phenotype, confirming its role in immune regulation in vitro. In vivo, the knockdown of osa and brahma was shown to enhance the expression of the Toll pathway-mediated antimicrobial peptides when the flies were challenged with Gram-positive bacteria Micrococcus luteus In this setting, osa knockdown had a particularly strong effect on immune effectors that are predominantly activated by the Imd pathway. Accordingly, Drosophila NF-κB Relish expression was increased by osa silencing. These transcriptional changes were associated with enhanced survival from M. luteus + E. faecalis infection. Besides regulating the expression of immune effector genes, osa RNA interference decreased the expression of a large group of genes involved in metabolism, particularly proteolysis. Of note, the expression of the recently characterized, immune-inducible gene Induced by Infection (IBIN) was diminished in osa knockdown flies. Although IBIN has been shown to modulate metabolism upon infection, the expression of selected Osa-regulated metabolism genes was not rescued by overexpressing IBIN. We conclude that the BAP complex regulates expression of genes involved in metabolism at least partially independent or downstream of IBIN Moreover, Osa affects the NF-κB-mediated immune response by regulating Drosophila NF-κB factor Relish expression.
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Affiliation(s)
- Susanna Valanne
- Laboratory of Experimental Immunology, Faculty of Medicine and Health Technology, 33014 Tampere University, Tampere, Finland
| | - Mirva Järvelä-Stölting
- Laboratory of Experimental Immunology, Faculty of Medicine and Health Technology, 33014 Tampere University, Tampere, Finland
| | - Sanna-Kaisa E Harjula
- Laboratory of Experimental Immunology, Faculty of Medicine and Health Technology, 33014 Tampere University, Tampere, Finland
| | - Henna Myllymäki
- Laboratory of Experimental Immunology, Faculty of Medicine and Health Technology, 33014 Tampere University, Tampere, Finland
| | - Tiina S Salminen
- Laboratory of Experimental Immunology, Faculty of Medicine and Health Technology, 33014 Tampere University, Tampere, Finland.,Laboratory of Mito-Immuno-Metabolism, Faculty of Medicine and Health Technology, 33014 Tampere University, Tampere, Finland
| | - Mika Rämet
- Laboratory of Experimental Immunology, Faculty of Medicine and Health Technology, 33014 Tampere University, Tampere, Finland; .,PEDEGO Research Unit, Faculty of Medicine, 90014 University of Oulu, Oulu, Finland.,Medical Research Center Oulu, 90014 University of Oulu, Oulu, Finland; and.,Department of Children and Adolescents, Oulu University Hospital, 90014 University of Oulu, Oulu, Finland
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