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Morejon B, Michel K. The expanded immunoregulatory protease network in mosquitoes is governed by gene co-expression. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.18.599423. [PMID: 38948760 PMCID: PMC11212970 DOI: 10.1101/2024.06.18.599423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
Serine protease cascades regulate key innate immune responses. In mosquitoes, these cascades involve clip-domain serine proteases and their non-catalytic homologs (CLIPs), forming a complex network whose make-up and structural organization is not fully understood. This study assessed the impact of 85 CLIPs on humoral immunity in Anopheles gambiae. By coupling RNAi with assays measuring antimicrobial activity and melanization, we identified 27 CLIPs as immunoregulators that together form two distinct subnetworks. CLIPs regulating antimicrobial activity were found to control infection resistance, as knockdowns reduced bacterial load and improved survival. Furthermore, our analysis of CLIP gene expression unveiled a novel immunoregulatory mechanism reliant on protease baseline co-expression rather than infection-induced upregulation. These findings underscore that despite its complexity mosquito immune regulation may be targeted for malaria interventions.
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Affiliation(s)
- Bianca Morejon
- Division of Biology, Kansas State University; Manhattan, KS, 66502, USA
| | - Kristin Michel
- Division of Biology, Kansas State University; Manhattan, KS, 66502, USA
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Chen J, Lin G, Ma K, Li Z, Liégeois S, Ferrandon D. A specific innate immune response silences the virulence of Pseudomonas aeruginosa in a latent infection model in the Drosophila melanogaster host. PLoS Pathog 2024; 20:e1012252. [PMID: 38833496 PMCID: PMC11178223 DOI: 10.1371/journal.ppat.1012252] [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: 02/23/2024] [Revised: 06/14/2024] [Accepted: 05/10/2024] [Indexed: 06/06/2024] Open
Abstract
Microbial pathogenicity often depends on the route of infection. For instance, P. aeruginosa or S. marcescens cause acute systemic infections when low numbers of bacteria are injected into D. melanogaster flies whereas flies succumb much slower to the continuous ingestion of these pathogens, even though both manage to escape from the gut compartment and reach the hemocoel. Here, we have developed a latent P. aeruginosa infection model by feeding flies on the bacteria for a short period. The bacteria stably colonize internal tissues yet hardly cause any damage since latently-infected flies live almost as long as noninfected control flies. The apparently dormant bacteria display particular characteristics in terms of bacterial colony morphology, composition of the outer cell wall, and motility. The virulence of these bacteria can however be reactivated upon wounding the host. We show that melanization but not the cellular or the systemic humoral response is the predominant host defense that establishes latency and may coerce the bacteria to a dormant state. In addition, the lasting activation of the melanization responses in latently-infected flies provides a degree of protection to the host against a secondary fungal infection. Latent infection by an ingested pathogen protects against a variety of homologous or heterologous systemic secondary infectious challenges, a situation previously described for the endosymbiotic Wolbachia bacteria, a guard against viral infections.
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Affiliation(s)
- Jing Chen
- Sino-French Hoffmann Institute, School of Basic Medical Sciences, Guangzhou Medical University, Guangzhou, China
| | - Guiying Lin
- Sino-French Hoffmann Institute, School of Basic Medical Sciences, Guangzhou Medical University, Guangzhou, China
- Université de Strasbourg, Strasbourg, France
- Modèles Insectes de l’Immunité Innée, UPR 9022 du CNRS, Strasbourg, France
| | - Kaiyu Ma
- Sino-French Hoffmann Institute, School of Basic Medical Sciences, Guangzhou Medical University, Guangzhou, China
| | - Zi Li
- Sino-French Hoffmann Institute, School of Basic Medical Sciences, Guangzhou Medical University, Guangzhou, China
| | - Samuel Liégeois
- Sino-French Hoffmann Institute, School of Basic Medical Sciences, Guangzhou Medical University, Guangzhou, China
- Université de Strasbourg, Strasbourg, France
- Modèles Insectes de l’Immunité Innée, UPR 9022 du CNRS, Strasbourg, France
| | - Dominique Ferrandon
- Sino-French Hoffmann Institute, School of Basic Medical Sciences, Guangzhou Medical University, Guangzhou, China
- Université de Strasbourg, Strasbourg, France
- Modèles Insectes de l’Immunité Innée, UPR 9022 du CNRS, Strasbourg, France
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Kloc M, Halasa M, Kubiak JZ, Ghobrial RM. Invertebrate Immunity, Natural Transplantation Immunity, Somatic and Germ Cell Parasitism, and Transposon Defense. Int J Mol Sci 2024; 25:1072. [PMID: 38256145 PMCID: PMC10815962 DOI: 10.3390/ijms25021072] [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: 12/06/2023] [Revised: 01/11/2024] [Accepted: 01/12/2024] [Indexed: 01/24/2024] Open
Abstract
While the vertebrate immune system consists of innate and adaptive branches, invertebrates only have innate immunity. This feature makes them an ideal model system for studying the cellular and molecular mechanisms of innate immunity sensu stricto without reciprocal interferences from adaptive immunity. Although invertebrate immunity is evolutionarily older and a precursor of vertebrate immunity, it is far from simple. Despite lacking lymphocytes and functional immunoglobulin, the invertebrate immune system has many sophisticated mechanisms and features, such as long-term immune memory, which, for decades, have been exclusively attributed to adaptive immunity. In this review, we describe the cellular and molecular aspects of invertebrate immunity, including the epigenetic foundation of innate memory, the transgenerational inheritance of immunity, genetic immunity against invading transposons, the mechanisms of self-recognition, natural transplantation, and germ/somatic cell parasitism.
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Affiliation(s)
- Malgorzata Kloc
- Houston Methodist Research Institute, Transplant Immunology, Houston, TX 77030, USA; (M.H.); (R.M.G.)
- Department of Surgery, Houston Methodist Hospital, Houston, TX 77030, USA
- Department of Genetics, MD Anderson Cancer Center, University of Texas, Houston, TX 77030, USA
| | - Marta Halasa
- Houston Methodist Research Institute, Transplant Immunology, Houston, TX 77030, USA; (M.H.); (R.M.G.)
- Department of Surgery, Houston Methodist Hospital, Houston, TX 77030, USA
| | - Jacek Z. Kubiak
- Laboratory of Molecular Oncology and Innovative Therapies, Military Institute of Medicine-National Research Institute (WIM-PIB), Szaserow 128, 04-141 Warsaw, Poland;
- Dynamics and Mechanics of Epithelia Group, Faculty of Medicine, Institute of Genetics and Development of Rennes, University of Rennes, CNRS, UMR 6290, 35043 Rennes, France
| | - Rafik M. Ghobrial
- Houston Methodist Research Institute, Transplant Immunology, Houston, TX 77030, USA; (M.H.); (R.M.G.)
- Department of Surgery, Houston Methodist Hospital, Houston, TX 77030, USA
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