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Maor-Landaw K, Smirnov M, Lotan T. The Tilapia Cyst Tissue Enclosing the Proliferating Myxobolus bejeranoi Parasite Exhibits Cornified Structure and Immune Barrier Function. Int J Mol Sci 2024; 25:5683. [PMID: 38891869 PMCID: PMC11171596 DOI: 10.3390/ijms25115683] [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: 04/25/2024] [Revised: 05/19/2024] [Accepted: 05/22/2024] [Indexed: 06/21/2024] Open
Abstract
Myxozoa, a unique group of obligate endoparasites within the phylum Cnidaria, can cause emerging diseases in wild and cultured fish populations. Recently, the myxozoan Myxobolus bejeranoi has been identified as a prevalent pathogen infecting the gills of cultured hybrid tilapia, leading to systemic immune suppression and considerable mortality. Here, we employed a proteomic approach to examine the impact of M. bejeranoi infection on fish gills, focusing on the structure of the granulomata, or cyst, formed around the proliferating parasite to prevent its spread to surrounding tissue. Enrichment analysis showed increased immune response and oxidative stress in infected gill tissue, most markedly in the cyst's wall. The intense immune reaction included a consortium of endopeptidase inhibitors, potentially combating the myxozoan arsenal of secreted proteases. Analysis of the cyst's proteome and histology staining indicated that keratin intermediate filaments contribute to its structural rigidity. Moreover, we uncovered skin-specific proteins, including a grainyhead-like transcription factor and a teleost-specific S100 calcium-binding protein that may play a role in epithelial morphogenesis and cysts formation. These findings deepen our understanding of the proteomic elements that grant the cyst its distinctive nature at the critical interface between the fish host and myxozoan parasite.
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Affiliation(s)
- Keren Maor-Landaw
- Marine Biology Department, The Leon H. Charney School of Marine Sciences, University of Haifa, Mt. Carmel, Haifa 3103301, Israel;
| | - Margarita Smirnov
- Central Fish Health Laboratory, Department of Fisheries and Aquaculture, Ministry of Agriculture and Rural Development, Nir David 1080300, Israel;
| | - Tamar Lotan
- Marine Biology Department, The Leon H. Charney School of Marine Sciences, University of Haifa, Mt. Carmel, Haifa 3103301, Israel;
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Saleh M, Hummel K, Schlosser S, Razzazi-Fazeli E, Bartholomew JL, Holzer A, Secombes CJ, El-Matbouli M. The myxozoans Myxobolus cerebralis and Tetracapsuloides bryosalmonae modulate rainbow trout immune responses: quantitative shotgun proteomics at the portals of entry after single and co-infections. Front Cell Infect Microbiol 2024; 14:1369615. [PMID: 38803570 PMCID: PMC11129561 DOI: 10.3389/fcimb.2024.1369615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Accepted: 04/05/2024] [Indexed: 05/29/2024] Open
Abstract
Introduction Little is known about the proteomic changes at the portals of entry in rainbow trout after infection with the myxozoan parasites, Myxobolus cerebralis, and Tetracapsuloides bryosalmonae. Whirling disease (WD) is a severe disease of salmonids, caused by the myxosporean M. cerebralis, while, proliferative kidney disease (PKD) is caused by T. bryosalmonae, which instead belongs to the class Malacosporea. Climate change is providing more suitable conditions for myxozoan parasites lifecycle, posing a high risk to salmonid aquaculture and contributing to the decline of wild trout populations in North America and Europe. Therefore, the aim of this study was to provide the first proteomic profiles of the host in the search for evasion strategies during single and coinfection with M. cerebralis and T. bryosalmonae. Methods One group of fish was initially infected with M. cerebralis and another group with T. bryosalmonae. After 30 days, half of the fish in each group were co-infected with the other parasite. Using a quantitative proteomic approach, we investigated proteomic changes in the caudal fins and gills of rainbow trout before and after co-infection. Results In the caudal fins, 16 proteins were differentially regulated post exposure to M. cerebralis, whereas 27 proteins were differentially modulated in the gills of the infected rainbow trout post exposure to T. bryosalmonae. After co-infection, 4 proteins involved in parasite recognition and the regulation of host immune responses were differentially modulated between the groups in the caudal fin. In the gills, 11 proteins involved in parasite recognition and host immunity, including 4 myxozoan proteins predicted to be virulence factors, were differentially modulated. Discussion The results of this study increase our knowledge on rainbow trout co-infections by myxozoan parasites and rainbow trout immune responses against myxozoans at the portals of entry, supporting a better understanding of these host-parasite interactions.
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Affiliation(s)
- Mona Saleh
- Division of Fish Health, University of Veterinary Medicine, Vienna, Austria
| | - Karin Hummel
- VetCore, University of Veterinary Medicine, Vienna, Austria
| | | | | | - Jerri L. Bartholomew
- Department of Microbiology, Oregon State University, Corvallis, OR, United States
| | - Astrid Holzer
- Division of Fish Health, University of Veterinary Medicine, Vienna, Austria
| | - Christopher J. Secombes
- Scottish Fish Immunology Research Centre, School of Biological Sciences, University of Aberdeen, Scotland, United Kingdom
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Maor-Landaw K, Avidor I, Rostowsky N, Salti B, Smirnov M, Ofek-Lalzar M, Levin L, Brekhman V, Lotan T. The Molecular Mechanisms Employed by the Parasite Myxobolus bejeranoi (Cnidaria: Myxozoa) from Invasion through Sporulation for Successful Proliferation in Its Fish Host. Int J Mol Sci 2023; 24:12824. [PMID: 37629003 PMCID: PMC10454682 DOI: 10.3390/ijms241612824] [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: 07/22/2023] [Revised: 08/08/2023] [Accepted: 08/14/2023] [Indexed: 08/27/2023] Open
Abstract
Myxozoa is a unique group of obligate endoparasites in the phylum Cnidaria that can cause emerging diseases in wild and cultured fish populations. Recently, we identified a new myxozoan species, Myxobolus bejeranoi, which infects the gills of cultured tilapia while suppressing host immunity. To uncover the molecular mechanisms underlying this successful parasitic strategy, we conducted transcriptomics analysis of M. bejeranoi throughout the infection. Our results show that histones, which are essential for accelerated cell division, are highly expressed even one day after invasion. As the infection progressed, conserved parasitic genes that are known to modulate the host immune reaction in different parasitic taxa were upregulated. These genes included energy-related glycolytic enzymes, as well as calreticulin, proteases, and miRNA biogenesis proteins. Interestingly, myxozoan calreticulin formed a distinct phylogenetic clade apart from other cnidarians, suggesting a possible function in parasite pathogenesis. Sporogenesis was in its final stages 20 days post-exposure, as spore-specific markers were highly expressed. Lastly, we provide the first catalog of transcription factors in a Myxozoa species, which is minimized compared to free-living cnidarians and is dominated by homeodomain types. Overall, these molecular insights into myxozoan infection support the concept that parasitic strategies are a result of convergent evolution.
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Affiliation(s)
- Keren Maor-Landaw
- Marine Biology Department, The Leon H. Charney School of Marine Sciences, University of Haifa, Mt. Carmel, Haifa 3103301, Israel; (K.M.-L.); (I.A.); (N.R.); (B.S.); (V.B.)
| | - Itamar Avidor
- Marine Biology Department, The Leon H. Charney School of Marine Sciences, University of Haifa, Mt. Carmel, Haifa 3103301, Israel; (K.M.-L.); (I.A.); (N.R.); (B.S.); (V.B.)
| | - Nadav Rostowsky
- Marine Biology Department, The Leon H. Charney School of Marine Sciences, University of Haifa, Mt. Carmel, Haifa 3103301, Israel; (K.M.-L.); (I.A.); (N.R.); (B.S.); (V.B.)
| | - Barbara Salti
- Marine Biology Department, The Leon H. Charney School of Marine Sciences, University of Haifa, Mt. Carmel, Haifa 3103301, Israel; (K.M.-L.); (I.A.); (N.R.); (B.S.); (V.B.)
| | - Margarita Smirnov
- Central Fish Health Laboratory, Department of Fisheries and Aquaculture, Ministry of Agriculture and Rural Development, Nir David 1080300, Israel;
| | - Maya Ofek-Lalzar
- Bioinformatic Unit, University of Haifa, Mt. Carmel, Haifa 3498838, Israel;
| | - Liron Levin
- Bioinformatics Core Facility, llse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel;
| | - Vera Brekhman
- Marine Biology Department, The Leon H. Charney School of Marine Sciences, University of Haifa, Mt. Carmel, Haifa 3103301, Israel; (K.M.-L.); (I.A.); (N.R.); (B.S.); (V.B.)
| | - Tamar Lotan
- Marine Biology Department, The Leon H. Charney School of Marine Sciences, University of Haifa, Mt. Carmel, Haifa 3103301, Israel; (K.M.-L.); (I.A.); (N.R.); (B.S.); (V.B.)
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4
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Shivam S, Ertl R, Sexl V, El-Matbouli M, Kumar G. Differentially expressed transcripts of Tetracapsuloides bryosalmonae (Cnidaria) between carrier and dead-end hosts involved in key biological processes: novel insights from a coupled approach of FACS and RNA sequencing. Vet Res 2023; 54:51. [PMID: 37365650 PMCID: PMC10291810 DOI: 10.1186/s13567-023-01185-7] [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: 01/23/2023] [Accepted: 05/29/2023] [Indexed: 06/28/2023] Open
Abstract
Tetracapsuloides bryosalmonae is a malacosporean endoparasite that infects a wide range of salmonids and causes proliferative kidney disease (PKD). Brown trout serves as a carrier host whereas rainbow trout represents a dead-end host. We thus asked if the parasite adapts to the different hosts by changing molecular mechanisms. We used fluorescent activated cell sorting (FACS) to isolate parasites from the kidney of brown trout and rainbow trout following experimental infection with T. bryosalmonae. The sorted parasite cells were then subjected to RNA sequencing. By this approach, we identified 1120 parasite transcripts that were expressed differentially in parasites derived from brown trout and rainbow trout. We found elevated levels of transcripts related to cytoskeleton organisation, cell polarity, peptidyl-serine phosphorylation in parasites sorted from brown trout. In contrast, transcripts related to translation, ribonucleoprotein complex biogenesis and subunit organisation, non-membrane bounded organelle assembly, regulation of protein catabolic process and protein refolding were upregulated in rainbow trout-derived parasites. These findings show distinct molecular adaptations of parasites, which may underlie their distinct outcomes in the two hosts. Moreover, the identification of these differentially expressed transcripts may enable the identification of novel drug targets that may be exploited as treatment against T. bryosalmonae. We here also describe for the first time how FACS based isolation of T. bryosalmonae cells from infected kidney of fish fosters research and allows to define differentially expressed parasite transcripts in carrier and dead-end fish hosts.
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Affiliation(s)
- Saloni Shivam
- Division of Fish Health, University of Veterinary Medicine Vienna, Vienna, Austria
- Karwar Regional Station of Indian Council of Agricultural Research, Central Marine Fisheries Research Institute, Karwar, Karnataka, India
| | - Reinhard Ertl
- VetCore Facility for Research, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Veronika Sexl
- Institute of Pharmacology and Toxicology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Mansour El-Matbouli
- Division of Fish Health, University of Veterinary Medicine Vienna, Vienna, Austria
- School of Biotechnology, Badr University in Cairo, Badr City, Cairo, Egypt
| | - Gokhlesh Kumar
- Division of Fish Health, University of Veterinary Medicine Vienna, Vienna, Austria.
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Neverov AM, Panchin AY, Mikhailov KV, Batueva MD, Aleoshin VV, Panchin YV. Apoptotic gene loss in Cnidaria is associated with transition to parasitism. Sci Rep 2023; 13:8015. [PMID: 37198195 PMCID: PMC10192318 DOI: 10.1038/s41598-023-34248-y] [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: 11/28/2022] [Accepted: 04/26/2023] [Indexed: 05/19/2023] Open
Abstract
The phylum Cnidaria consists of several morphologically diverse classes including Anthozoa, Cubozoa, Hydrozoa, Polypodiozoa, Scyphozoa, Staurozoa, and Myxozoa. Myxozoa comprises two subclasses of obligate parasites-Myxosporea and Malacosporea, which demonstrate various degrees of simplification. Myxosporea were previously reported to lack the majority of core protein domains of apoptotic proteins including caspases, Bcl-2, and APAF-1 homologs. Other sequenced Cnidaria, including the parasite Polypodium hydriforme from Polypodiozoa do not share this genetic feature. Whether this loss of core apoptotic proteins is unique to Myxosporea or also present in its sister subclass Malacosporea was not previously investigated. We show that the presence of core apoptotic proteins gradually diminishes from free-living Cnidaria to Polypodium to Malacosporea to Myxosporea. This observation does not favor the hypothesis of catastrophic simplification of Myxosporea at the genetic level, but rather supports a stepwise adaptation to parasitism that likely started from early parasitic ancestors that gave rise to Myxozoa.
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Affiliation(s)
- Alexander M Neverov
- Department of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, Russian Federation, 119234.
| | - Alexander Y Panchin
- Kharkevich Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, Russian Federation, 127994
| | - Kirill V Mikhailov
- Kharkevich Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, Russian Federation, 127994
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Leninskiye Gory 1-40, Moscow, Russian Federation, 119991
| | - Marina D Batueva
- Institute of General and Experimental Biology Siberian Branch of Russian Academy of Sciences, Ulan-Ude, Russian Federation, 670047
| | - Vladimir V Aleoshin
- Kharkevich Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, Russian Federation, 127994
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Leninskiye Gory 1-40, Moscow, Russian Federation, 119991
| | - Yuri V Panchin
- Kharkevich Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, Russian Federation, 127994
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Leninskiye Gory 1-40, Moscow, Russian Federation, 119991
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Chan JTH, Picard-Sánchez A, Majstorović J, Rebl A, Koczan D, Dyčka F, Holzer AS, Korytář T. Red blood cells in proliferative kidney disease-rainbow trout ( Oncorhynchus mykiss) infected by Tetracapsuloides bryosalmonae harbor IgM + red blood cells. Front Immunol 2023; 14:1041325. [PMID: 36875079 PMCID: PMC9975563 DOI: 10.3389/fimmu.2023.1041325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2022] [Accepted: 02/01/2023] [Indexed: 02/17/2023] Open
Abstract
The myxozoan parasite Tetracapsuloides bryosalmonae is the causative agent of proliferative kidney disease (PKD)-a disease of salmonid fishes, notably of the commercially farmed rainbow trout Oncorhynchus mykiss. Both wild and farmed salmonids are threatened by this virulent/deadly disease, a chronic immunopathology characterized by massive lymphocyte proliferation and hyperplasia, which manifests as swollen kidneys in susceptible hosts. Studying the immune response towards the parasite helps us understand the causes and consequences of PKD. While examining the B cell population during a seasonal outbreak of PKD, we unexpectedly detected the B cell marker immunoglobulin M (IgM) on red blood cells (RBCs) of infected farmed rainbow trout. Here, we studied the nature of this IgM and this IgM+ cell population. We verified the presence of surface IgM via parallel approaches: flow cytometry, microscopy, and mass spectrometry. The levels of surface IgM (allowing complete resolution of IgM- RBCs from IgM+ RBCs) and frequency of IgM+ RBCs (with up to 99% of RBCs being positive) have not been described before in healthy fishes nor those suffering from disease. To assess the influence of the disease on these cells, we profiled the transcriptomes of teleost RBCs in health and disease. Compared to RBCs originating from healthy fish, PKD fundamentally altered RBCs in their metabolism, adhesion, and innate immune response to inflammation. In summary, RBCs play a larger role in host immunity than previously appreciated. Specifically, our findings indicate that the nucleated RBCs of rainbow trout interact with host IgM and contribute to the immune response in PKD.
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Affiliation(s)
- Justin T H Chan
- Laboratory of Fish Protistology, Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czechia
| | - Amparo Picard-Sánchez
- Laboratory of Fish Protistology, Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czechia
| | - Jovana Majstorović
- Laboratory of Fish Protistology, Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czechia.,Faculty of Science, University of South Bohemia, České Budějovice, Czechia
| | - Alexander Rebl
- Fish Genetics Unit, Institute of Genome Biology, Research Institute for Farm Animal Biology, Dummerstorf, Germany
| | - Dirk Koczan
- Core Facility for Microarray Analysis, Institute for Immunology, Rostock University Medical Centre, Rostock, Germany
| | - Filip Dyčka
- Faculty of Science, University of South Bohemia, České Budějovice, Czechia
| | - Astrid S Holzer
- Laboratory of Fish Protistology, Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czechia.,Division of Fish Health, Veterinary University of Vienna, Vienna, Austria
| | - Tomáš Korytář
- Laboratory of Fish Protistology, Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czechia.,South Bohemian Research Centre of Aquaculture and Biodiversity of Hydrocenoses, Institute of Aquaculture and Protection of Waters, Faculty of Fisheries and Protection of Waters, University of South Bohemia, České Budějovice, Czechia
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Kumar G, Sudhagar A, Shivam S, Nilsen F, Bartholomew JL, El-Matbouli M. Identification of in vivo induced antigens of the malacosporean parasite Tetracapsuloides bryosalmonae (Cnidaria) using in vivo induced antigen technology. Front Cell Infect Microbiol 2022; 12:1032347. [DOI: 10.3389/fcimb.2022.1032347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 09/30/2022] [Indexed: 11/13/2022] Open
Abstract
Tetracapsuloides bryosalmonae is a malacosporean endoparasite that causes proliferative kidney disease (PKD) in wild and farmed salmonids in Europe and North America. The life cycle of T. bryosalmonae completes between invertebrate bryozoan and vertebrate fish hosts. Inside the fish, virulence factors of T. bryosalmonae are induced during infection or interactions with host cells. T. bryosalmonae genes expressed in vivo are likely to be important in fish pathogenesis. Herein, we identify in vivo induced antigens of T. bryosalmonae during infection in brown trout (Salmo trutta) using in vivo induced antigen technology (IVIAT). Brown trout were exposed to the spores of T. bryosalmonae and were sampled at different time points. The pooled sera were first pre-adsorbed with antigens to remove false positive results. Subsequently, adsorbed sera were used to screen a T. bryosalmonae cDNA phage expression library. Immunoscreening analysis revealed 136 immunogenic T. bryosalmonae proteins induced in brown trout during parasite development. They are involved in signal transduction, transport, metabolism, ion-protein binding, protein folding, and also include hypothetical proteins, of so far unknown functions. The identified in vivo induced antigens will be useful in the understanding of T. bryosalmonae pathogenesis during infection in susceptible hosts. Some of the antigens found may have significant implications for the discovery of candidate molecules for the development of potential therapies and preventive measures against T. bryosalmonae in salmonids.
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Sudhagar A, El-Matbouli M, Kumar G. Genome-wide alternative splicing profile in the posterior kidney of brown trout (Salmo trutta) during proliferative kidney disease. BMC Genomics 2022; 23:446. [PMID: 35710345 PMCID: PMC9204890 DOI: 10.1186/s12864-022-08685-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2022] [Accepted: 06/08/2022] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND The cnidarian myxozoan parasite Tetracapsuloides bryosalmonae causes chronic proliferative kidney disease (PKD) in salmonids. This parasite is a serious threat to wild and cultured salmonids. T. bryosalmonae undergoes intra-luminal sporogonic development in the kidney of brown trout (Salmo trutta) and the viable spores are released via urine. We investigated the alternative splicing pattern in the posterior kidney of brown trout during PKD. RESULTS RNA-seq data were generated from the posterior kidney of brown trout collected at 12 weeks post-exposure to T. bryosalmonae. Subsequently, this data was mapped to the brown trout genome. About 153 significant differently expressed alternatively spliced (DEAS) genes, (delta PSI = 5%, FDR P-value < 0.05) were identified from 19,722 alternatively spliced events. Among the DEAS genes, the least and most abundant alternative splicing types were alternative 5' splice site (5.23%) and exon skipping (70.59%), respectively. The DEAS genes were significantly enriched for sodium-potassium transporter activity and ion homeostasis (ahcyl1, atp1a3a, atp1a1a.1, and atp1a1a.5). The protein-protein interaction network analysis enriched two local network clusters namely cation transporting ATPase C-terminus and Sodium/potassium ATPase beta chain cluster, and mixed inclusion of Ion homeostasis and EF-hand domain cluster. Furthermore, the human disease-related salmonella infection pathway was significantly enriched in the protein-protein interaction network. CONCLUSION This study provides the first baseline information about alternative splicing in brown trout during PKD. The generated data lay a foundation for further functional molecular studies in PKD - brown trout infection model. The information generated from the present study can help to develop therapeutic strategies for PKD in the future.
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Affiliation(s)
- Arun Sudhagar
- Clinical Division of Fish Medicine, University of Veterinary Medicine Vienna, 1210, Vienna, Austria
- Peninsular and Marine Fish Genetic Resources Centre, ICAR - National Bureau of Fish Genetic Resources, Kochi, Kerala, 682 018, India
| | - Mansour El-Matbouli
- Clinical Division of Fish Medicine, University of Veterinary Medicine Vienna, 1210, Vienna, Austria
| | - Gokhlesh Kumar
- Clinical Division of Fish Medicine, University of Veterinary Medicine Vienna, 1210, Vienna, Austria.
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Ros A, Schmidt-Posthaus H, Brinker A. Mitigating human impacts including climate change on proliferative kidney disease in salmonids of running waters. JOURNAL OF FISH DISEASES 2022; 45:497-521. [PMID: 35100455 DOI: 10.1111/jfd.13585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 01/10/2022] [Accepted: 01/14/2022] [Indexed: 06/14/2023]
Abstract
Over the last two decades, an increasing number of reports have identified a decline in salmonid populations, possibly linked to infection with the parasite Tetracapsuloides bryosalmonae and the corresponding disease, that is, proliferative kidney disease (PKD). The life cycle of this myxozoan parasite includes sessile bryozoan species as invertebrate host, which facilitates the distribution of the parasite in running waters. As the disease outcome is temperature dependent, the impact of the disease on salmonid populations is increasing with global warming due to climate change. The goal of this review is to provide a detailed overview of measures to mitigate the effects of PKD on salmonid populations. It first summarizes the parasite life cycle, temperature-driven disease dynamics and new immunological and molecular research into disease resistance and, based on this, discusses management possibilities. Sophisticated management actions focusing on local adaptation of salmonid populations, restoration of the riverine ecosystem and keeping water temperatures cool are necessary to reduce the negative effects of PKD. Such actions include temporary stocking with PKD-resistant salmonids, as this may assist in conserving current populations that fail to reproduce.
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Affiliation(s)
- Albert Ros
- Fisheries Research Station of Baden-Württemberg, LAZBW, Langenargen, Germany
| | - Heike Schmidt-Posthaus
- Institute for Fish and Wildlife Health, Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Alexander Brinker
- Fisheries Research Station of Baden-Württemberg, LAZBW, Langenargen, Germany
- University of Konstanz, Konstanz, Germany
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10
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Guo Q, Atkinson SD, Xiao B, Zhai Y, Bartholomew JL, Gu Z. A myxozoan genome reveals mosaic evolution in a parasitic cnidarian. BMC Biol 2022; 20:51. [PMID: 35177085 PMCID: PMC8855578 DOI: 10.1186/s12915-022-01249-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 02/07/2022] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Parasite evolution has been conceptualized as a process of genetic loss and simplification. Contrary to this model, there is evidence of expansion and conservation of gene families related to essential functions of parasitism in some parasite genomes, reminiscent of widespread mosaic evolution-where subregions of a genome have different rates of evolutionary change. We found evidence of mosaic genome evolution in the cnidarian Myxobolus honghuensis, a myxozoan parasite of fish, with extremely simple morphology. RESULTS We compared M. honghuensis with other myxozoans and free-living cnidarians, and determined that it has a relatively larger myxozoan genome (206 Mb), which is less reduced and less compact due to gene retention, large introns, transposon insertion, but not polyploidy. Relative to other metazoans, the M. honghuensis genome is depleted of neural genes and has only the simplest animal immune components. Conversely, it has relatively more genes involved in stress resistance, tissue invasion, energy metabolism, and cellular processes compared to other myxozoans and free-living cnidarians. We postulate that the expansion of these gene families is the result of evolutionary adaptations to endoparasitism. M. honghuensis retains genes found in free-living Cnidaria, including a reduced nervous system, myogenic components, ANTP class Homeobox genes, and components of the Wnt and Hedgehog pathways. CONCLUSIONS Our analyses suggest that the M. honghuensis genome evolved as a mosaic of conservative, divergent, depleted, and enhanced genes and pathways. These findings illustrate that myxozoans are not as genetically simple as previously regarded, and the evolution of some myxozoans is driven by both genomic streamlining and expansion.
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Affiliation(s)
- Qingxiang Guo
- Department of Aquatic Animal Medicine, College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
- Hubei Engineering Technology Research Center for Aquatic Animal Diseases Control and Prevention, Wuhan, 430070, People's Republic of China
| | - Stephen D Atkinson
- Department of Microbiology, Oregon State University, Corvallis, OR, 97331, USA
| | - Bin Xiao
- Department of Aquatic Animal Medicine, College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
- Hubei Engineering Technology Research Center for Aquatic Animal Diseases Control and Prevention, Wuhan, 430070, People's Republic of China
| | - Yanhua Zhai
- Department of Aquatic Animal Medicine, College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China
- Hubei Engineering Technology Research Center for Aquatic Animal Diseases Control and Prevention, Wuhan, 430070, People's Republic of China
| | - Jerri L Bartholomew
- Department of Microbiology, Oregon State University, Corvallis, OR, 97331, USA
| | - Zemao Gu
- Department of Aquatic Animal Medicine, College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China.
- Hubei Engineering Technology Research Center for Aquatic Animal Diseases Control and Prevention, Wuhan, 430070, People's Republic of China.
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Alama-Bermejo G, Bartošová-Sojková P, Atkinson SD, Holzer AS, Bartholomew JL. Proteases as Therapeutic Targets Against the Parasitic Cnidarian Ceratonova shasta: Characterization of Molecules Key to Parasite Virulence In Salmonid Hosts. Front Cell Infect Microbiol 2022; 11:804864. [PMID: 35071050 PMCID: PMC8777295 DOI: 10.3389/fcimb.2021.804864] [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: 10/29/2021] [Accepted: 11/24/2021] [Indexed: 11/13/2022] Open
Abstract
Proteases and their inhibitors play critical roles in host-parasite interactions and in the outcomes of infections. Ceratonova shasta is a myxozoan pathogen that causes enteronecrosis in economically important salmonids from the Pacific Northwest of North America. This cnidarian parasite has host-specific genotypes with varying virulence, making it a powerful system to decipher virulence mechanisms in myxozoans. Using C. shasta genome and transcriptome, we identified four proteases of different catalytic types: cathepsin D (aspartic), cathepsin L and Z-like (cysteine) and aminopeptidase-N (metallo); and a stefin (cysteine protease inhibitor), which implied involvement in virulence and hence represent target molecules for the development of therapeutic strategies. We characterized, annotated and modelled their 3D protein structure using bioinformatics and computational tools. We quantified their expression in C. shasta genotype 0 (low virulence, no mortality) and IIR (high virulence and mortality) in rainbow trout Oncorhynchus mykiss, to demonstrate that there are major differences between the genotypes during infection and parasite development. High proliferation of genotype IIR was associated with high expression of the cathepsin D and the stefin, likely correlated with high nutrient demands and to regulate cell metabolism, with upregulation preceding massive proliferation and systemic dispersion. In contrast, upregulation of the cathepsin L and Z-like cysteine proteases may have roles in host immune evasion in genotype 0 infections, which are associated with low proliferation, low inflammation and non-destructive development. In contrast to the other proteases, C. shasta aminopeptidase-N appears to have a prominent role in nematocyst formation in both genotypes, but only during sporogenesis. Homology searches of C. shasta proteases against other myxozoan transcriptomes revealed a high abundance of cathepsin L and aminopeptidase homologs suggesting common gene requirements across species. Our study identified molecules of potential therapeutic significance for aquaculture and serves as a baseline for future research aimed at functional characterisation of these targets.
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Affiliation(s)
- Gema Alama-Bermejo
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czechia.,Department of Microbiology, Oregon State University, Corvallis, OR, United States
| | - Pavla Bartošová-Sojková
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czechia
| | - Stephen D Atkinson
- Department of Microbiology, Oregon State University, Corvallis, OR, United States
| | - Astrid S Holzer
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czechia
| | - Jerri L Bartholomew
- Department of Microbiology, Oregon State University, Corvallis, OR, United States
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Holzer AS, Piazzon MC, Barrett D, Bartholomew JL, Sitjà-Bobadilla A. To React or Not to React: The Dilemma of Fish Immune Systems Facing Myxozoan Infections. Front Immunol 2021; 12:734238. [PMID: 34603313 PMCID: PMC8481699 DOI: 10.3389/fimmu.2021.734238] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 09/01/2021] [Indexed: 11/13/2022] Open
Abstract
Myxozoans are microscopic, metazoan, obligate parasites, belonging to the phylum Cnidaria. In contrast to the free-living lifestyle of most members of this taxon, myxozoans have complex life cycles alternating between vertebrate and invertebrate hosts. Vertebrate hosts are primarily fish, although they are also reported from amphibians, reptiles, trematodes, mollusks, birds and mammals. Invertebrate hosts include annelids and bryozoans. Most myxozoans are not overtly pathogenic to fish hosts, but some are responsible for severe economic losses in fisheries and aquaculture. In both scenarios, the interaction between the parasite and the host immune system is key to explain such different outcomes of this relationship. Innate immune responses contribute to the resistance of certain fish strains and species, and the absence or low levels of some innate and regulatory factors explain the high pathogenicity of some infections. In many cases, immune evasion explains the absence of a host response and allows the parasite to proliferate covertly during the first stages of the infection. In some infections, the lack of an appropriate regulatory response results in an excessive inflammatory response, causing immunopathological consequences that are worse than inflicted by the parasite itself. This review will update the available information about the immune responses against Myxozoa, with special focus on T and B lymphocyte and immunoglobulin responses, how these immune effectors are modulated by different biotic and abiotic factors, and on the mechanisms of immune evasion targeting specific immune effectors. The current and future design of control strategies for myxozoan diseases is based on understanding this myxozoan-fish interaction, and immune-based strategies such as improvement of innate and specific factors through diets and additives, host genetic selection, passive immunization and vaccination, are starting to be considered.
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Affiliation(s)
- Astrid S Holzer
- Institute of Parasitology, Biology Centre of the Czech Academy of Sciences, České Budějovice, Czechia
| | - M Carla Piazzon
- Fish Pathology Group, Institute of Aquaculture Torre de la Sal - Consejo Superior de Investigaciones Científicas (IATS-CSIC), Castellón, Spain
| | - Damien Barrett
- Department of Microbiology, Oregon State University, Corvallis, OR, United States
| | - Jerri L Bartholomew
- Department of Microbiology, Oregon State University, Corvallis, OR, United States
| | - Ariadna Sitjà-Bobadilla
- Fish Pathology Group, Institute of Aquaculture Torre de la Sal - Consejo Superior de Investigaciones Científicas (IATS-CSIC), Castellón, Spain
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Eszterbauer E, Szegő D, Ursu K, Sipos D, Gellért Á. Serine protease inhibitors of the whirling disease parasite Myxobolus cerebralis (Cnidaria, Myxozoa): Expression profiling and functional predictions. PLoS One 2021; 16:e0249266. [PMID: 33780500 PMCID: PMC8007001 DOI: 10.1371/journal.pone.0249266] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 03/15/2021] [Indexed: 11/19/2022] Open
Abstract
Here, we studied the expression pattern and putative function of four, previously identified serine protease inhibitors (serpins) of Myxobolus cerebralis, a pathogenic myxozoan species (Cnidaria: Myxozoa) causing whirling disease of salmonid fishes. The relative expression profiles of serpins were determined at different developmental stages both in fish and in annelid hosts using serpin-specific qPCR assays. The expression of serpin Mc-S1 was similar throughout the life cycle, whereas a significant decrease was detected in the relative expression of Mc-S3 and Mc-S5 during the development in fish, and then in the sporogonic stage in the worm host. A decreasing tendency could also be observed in the expression of Mc-S4 in fish, which was, however, upregulated in the worm host. For the first time, we predicted the function of M. cerebralis serpins by the use of several bioinformatics-based applications. Mc-S1 is putatively a chymotrypsin-like inhibitor that locates extracellularly and is capable of heparin binding. The other three serpins are caspase-like inhibitors, and they are probably involved in protease and cell degradation processes during the early stage of fish invasion.
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Affiliation(s)
- Edit Eszterbauer
- Institute for Veterinary Medical Research, Centre for Agricultural Research, Budapest, Hungary
| | - Dóra Szegő
- Institute for Veterinary Medical Research, Centre for Agricultural Research, Budapest, Hungary
| | - Krisztina Ursu
- Veterinary Diagnostic Directorate, National Food Chain Safety Office, Budapest, Hungary
| | - Dóra Sipos
- Institute for Veterinary Medical Research, Centre for Agricultural Research, Budapest, Hungary
| | - Ákos Gellért
- Institute for Veterinary Medical Research, Centre for Agricultural Research, Budapest, Hungary
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Advances and Discoveries in Myxozoan Genomics. Trends Parasitol 2021; 37:552-568. [PMID: 33619004 DOI: 10.1016/j.pt.2021.01.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 01/20/2021] [Accepted: 01/23/2021] [Indexed: 12/21/2022]
Abstract
Myxozoans are highly diverse and globally distributed cnidarian endoparasites in freshwater and marine habitats. They have adopted a heteroxenous life cycle, including invertebrate and fish hosts, and have been associated with diseases in aquaculture and wild fish stocks. Despite their importance, genomic resources of myxozoans have proven difficult to obtain due to their miniaturized and derived genome character and close associations with fish tissues. The first 'omic' datasets have now become the main resource for a better understanding of host-parasite interactions, virulence, and diversity, but also the evolutionary history of myxozoans. In this review, we discuss recent genomic advances in the field and outline outstanding questions to be answered with continuous and improved efforts of generating myxozoan genomic data.
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Know your enemy - transcriptome of myxozoan Tetracapsuloides bryosalmonae reveals potential drug targets against proliferative kidney disease in salmonids. Parasitology 2021; 148:726-739. [PMID: 33478602 PMCID: PMC8056827 DOI: 10.1017/s003118202100010x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The myxozoan Tetracapsuloides bryosalmonae is a widely spread endoparasite that causes proliferative kidney disease (PKD) in salmonid fish. We developed an in silico pipeline to separate transcripts of T. bryosalmonae from the kidney tissue of its natural vertebrate host, brown trout (Salmo trutta). After stringent filtering, we constructed a partial transcriptome assembly T. bryosalmonae, comprising 3427 transcripts. Based on homology-restricted searches of the assembled parasite transcriptome and Atlantic salmon (Salmo salar) proteome, we identified four protein targets (Endoglycoceramidase, Legumain-like protease, Carbonic anhydrase 2, Pancreatic lipase-related protein 2) for the development of anti-parasitic drugs against T. bryosalmonae. Earlier work of these proteins on parasitic protists and helminths suggests that the identified anti-parasitic drug targets represent promising chemotherapeutic candidates also against T. bryosalmonae, and strengthen the view that the known inhibitors can be effective in evolutionarily distant organisms. In addition, we identified differentially expressed T. bryosalmonae genes between moderately and severely infected fish, indicating an increased abundance of T. bryosalmonae sporogonic stages in fish with low parasite load. In conclusion, this study paves the way for future genomic research in T. bryosalmonae and represents an important step towards the development of effective drugs against PKD.
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