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Yanagida T, Nakayama K, Sawada T, Honjo M, Murakami S, Iida T, Hirose E, Kitamura SI. Innate immunity in the edible ascidian Halocynthia roretzi developing soft tunic syndrome: Hemolymph can eliminate the causative flagellates and discriminate allogeneic hemocytes. FISH & SHELLFISH IMMUNOLOGY 2022; 127:659-665. [PMID: 35779813 DOI: 10.1016/j.fsi.2022.06.037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 06/16/2022] [Accepted: 06/21/2022] [Indexed: 06/15/2023]
Abstract
The infection of the kinetoplastid flagellate Azumiobodo hoyamushi causes soft tunic syndrome that often results in mass mortality in the aquaculture of the edible ascidian Halocynthia roretzi. In the diseased ascidian individuals, the flagellates are exclusively found in the tunic matrix that entirely cover the epidermis, and never invade into internal tissues, such as a mantle. The present study for the first time demonstrated that the ascidian blood plasma and hemolymph have an activity to agglutinate and disintegrate the flagellates, suggesting the innate immunity protects the internal tissue from the invasion of A. hoyamushi. This activity is indifferent between the healthy and the diseased individuals. Allo-specific recognition and cytotoxic reaction among ascidian hemocytes, so-called contact reaction, occur among the individuals of healthy-healthy, healthy-diseased, and diseased-diseased combination, and therefore, the hemocytes from diseased individuals still retain the allo-reactivity. Moreover, the allo-reactive combinations are not changed under the presence of the flagellates, indicating the flagellates neither suppress nor induce the effector system of the contact reaction. These results suggest that the infection of A. hoyamushi does not impair the innate immunity in the ascidian hemolymph.
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Affiliation(s)
- Tetsuya Yanagida
- Joint Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi, 753-8515, Japan
| | - Kei Nakayama
- Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama, Ehime, 790-8577, Japan
| | - Tomoo Sawada
- Graduate School of Medicine, Yamaguchi University, Ube, Yamaguchi, 755-8505, Japan
| | - Miho Honjo
- Miyagi Prefecture Fisheries Technology Institute, Ishinomaki, Miyagi, 986-2135, Japan
| | - Shoko Murakami
- Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama, Ehime, 790-8577, Japan
| | - Takaji Iida
- Faculty of Veterinary Medicine, Okayama University of Science, Imabari, Ehime, 794-8555, Japan
| | - Euichi Hirose
- Department of Chemistry, Biology, and Marine Science, Faculty of Science, University of the Ryukyus, Okinawa, 903-0213, Japan
| | - Shin-Ichi Kitamura
- Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama, Ehime, 790-8577, Japan.
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Bai W, Wells ML, Lai WS, Hicks SN, Burkholder AB, Perera L, Kimmel AR, Blackshear PJ. A post-transcriptional regulon controlled by TtpA, the single tristetraprolin family member expressed in Dictyostelium discoideum. Nucleic Acids Res 2021; 49:11920-11937. [PMID: 34718768 DOI: 10.1093/nar/gkab983] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 10/05/2021] [Accepted: 10/12/2021] [Indexed: 12/30/2022] Open
Abstract
Post-transcriptional processes mediated by mRNA binding proteins represent important control points in gene expression. In eukaryotes, mRNAs containing specific AU-rich motifs are regulated by binding of tristetraprolin (TTP) family tandem zinc finger proteins, which promote mRNA deadenylation and decay, partly through interaction of a conserved C-terminal CNOT1 binding (CNB) domain with CCR4-NOT protein complexes. The social ameba Dictyostelium discoideum shared a common ancestor with humans more than a billion years ago, and expresses only one TTP family protein, TtpA, in contrast to three members expressed in humans. Evaluation of ttpA null-mutants identified six transcripts that were consistently upregulated compared to WT during growth and early development. The 3'-untranslated regions (3'-UTRs) of all six 'TtpA-target' mRNAs contained multiple TTP binding motifs (UUAUUUAUU), and one 3'-UTR conferred TtpA post-transcriptional stability regulation to a heterologous mRNA that was abrogated by mutations in the core TTP-binding motifs. All six target transcripts were upregulated to similar extents in a C-terminal truncation mutant, in contrast to less severe effects of analogous mutants in mice. All six target transcripts encoded probable membrane proteins. In Dictyostelium, TtpA may control an 'RNA regulon', where a single RNA binding protein, TtpA, post-transcriptionally co-regulates expression of several functionally related proteins.
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Affiliation(s)
- Wenli Bai
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892, USA
| | - Melissa L Wells
- The Signal Transduction Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - Wi S Lai
- The Signal Transduction Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - Stephanie N Hicks
- The Signal Transduction Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - Adam B Burkholder
- Integrative Bioinformatics Support Group, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - Lalith Perera
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
| | - Alan R Kimmel
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892, USA
| | - Perry J Blackshear
- The Signal Transduction Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA.,The Departments of Medicine and Biochemistry, Duke University Medical Center, Durham, NC 27710, USA
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