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Leeuwis RHJ, Hall JR, Zanuzzo FS, Smith N, Clow KA, Kumar S, Vasquez I, Goetz FW, Johnson SC, Rise ML, Santander J, Gamperl AK. Climate change can impair bacterial pathogen defences in sablefish via hypoxia-mediated effects on adaptive immunity. Dev Comp Immunol 2024; 156:105161. [PMID: 38521379 DOI: 10.1016/j.dci.2024.105161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 03/13/2024] [Accepted: 03/13/2024] [Indexed: 03/25/2024]
Abstract
Low-oxygen levels (hypoxia) in aquatic habitats are becoming more common because of global warming and eutrophication. However, the effects on the health/disease status of fishes, the world's largest group of vertebrates, are unclear. Therefore, we assessed how long-term hypoxia affected the immune function of sablefish, an ecologically and economically important North Pacific species, including the response to a formalin-killed Aeromonas salmonicida bacterin. Sablefish were held at normoxia or hypoxia (100% or 40% air saturated seawater, respectively) for 6-16 weeks, while we measured a diverse array of immunological traits. Given that the sablefish is a non-model organism, this involved the development of a species-specific methodological toolbox comprised of qPCR primers for 16 key immune genes, assays for blood antibacterial defences, the assessment of blood immunoglobulin (IgM) levels with ELISA, and flow cytometry and confocal microscopy techniques. We show that innate immune parameters were typically elevated in response to the bacterial antigens, but were not substantially affected by hypoxia. In contrast, hypoxia completely prevented the ∼1.5-fold increase in blood IgM level that was observed under normoxic conditions following bacterin exposure, implying a serious impairment of adaptive immunity. Since the sablefish is naturally hypoxia tolerant, our results demonstrate that climate change-related deoxygenation may be a serious threat to the immune competency of fishes.
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Affiliation(s)
- Robine H J Leeuwis
- Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, NL, A1C 5S7, Canada.
| | - Jennifer R Hall
- Aquatic Research Cluster, CREAIT Network, Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, NL, A1C 5S7, Canada
| | - Fábio S Zanuzzo
- Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, NL, A1C 5S7, Canada
| | - Nicole Smith
- Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, NL, A1C 5S7, Canada
| | - Kathy A Clow
- Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, NL, A1C 5S7, Canada
| | - Surendra Kumar
- Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, NL, A1C 5S7, Canada
| | - Ignacio Vasquez
- Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, NL, A1C 5S7, Canada
| | - Frederick W Goetz
- School of Freshwater Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI, 53204, USA
| | - Stewart C Johnson
- Pacific Biological Station, Department of Fisheries and Oceans, Nanaimo, BC, V9T 6N7, Canada
| | - Matthew L Rise
- Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, NL, A1C 5S7, Canada
| | - Javier Santander
- Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, NL, A1C 5S7, Canada
| | - A Kurt Gamperl
- Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, NL, A1C 5S7, Canada
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Vasquez I, Cao T, Hossain A, Valderrama K, Gnanagobal H, Dang M, Leeuwis RHJ, Ness M, Campbell B, Gendron R, Kao K, Westcott J, Gamperl AK, Santander J. Aeromonas salmonicida infection kinetics and protective immune response to vaccination in sablefish (Anoplopoma fimbria). Fish Shellfish Immunol 2020; 104:557-566. [PMID: 32592927 DOI: 10.1016/j.fsi.2020.06.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 05/29/2020] [Accepted: 06/02/2020] [Indexed: 06/11/2023]
Abstract
Effective vaccine programs against Aeromonas salmonicida have been identified as a high priority area for the sablefish (Anoplopoma fimbria) aquaculture. In this study, we established an A. salmonicida infection model in sablefish to evaluate the efficacy of commercial vaccines and an autogenous vaccine preparation. Groups of 40 fish were intraperitoneally (ip) injected with different doses of A. salmonicida J410 isolated from infected sablefish to calculate the median lethal dose (LD50). Samples of blood, head kidney, spleen, brain, and liver were also collected at different time points to determine the infection kinetics. The LD50 was estimated as ~3 × 105 CFU/dose. To evaluate the immune protection provided by an autogenous vaccine and two commercial vaccines in a common garden experimental design, 140 fish were PIT-tagged, vaccinated and distributed equally into 4 tanks (35 fish for each group, including a control group). Blood samples were taken every 2 weeks to evaluate IgM titers. At 10 weeks post-immunization, all groups were ip challenged with 100 times the calculated LD50 for A. salmonicida J410. A. salmonicida was detected after 5 days post-infection (dpi) in all collected tissues. At 30 days post-challenge the relative percentage survival (RPS) with respect to the control group was calculated for each vaccine. The RPS for the bacterin mix was 65.22%, for Forte Micro 4® vaccine was 56.52% and for Alpha Ject Micro 4® was 30.43%, and these RPS values were reflected by A. salmonicida tissue colonization levels at 10 days post-challenge. Total IgM titers peaked at 6-8 weeks post-immunization, where the autogenous vaccine group showed the highest IgM titers and these values were consistent with the RPS data. Also, we determined that the A. salmonicida A-layer binds to immunoglobulins F(ab)' in a non-specific fashion, interfering with immune assays and potentially vaccine efficacy. Our results indicate that vaccine design influences sablefish immunity and provide a guide for future sablefish vaccine programs.
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Affiliation(s)
- Ignacio Vasquez
- Marine Microbial Pathogenesis and Vaccinology Laboratory, Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Trung Cao
- Marine Microbial Pathogenesis and Vaccinology Laboratory, Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Ahmed Hossain
- Marine Microbial Pathogenesis and Vaccinology Laboratory, Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Katherinne Valderrama
- Marine Microbial Pathogenesis and Vaccinology Laboratory, Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Hajarooba Gnanagobal
- Marine Microbial Pathogenesis and Vaccinology Laboratory, Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, NL, Canada
| | - My Dang
- Marine Microbial Pathogenesis and Vaccinology Laboratory, Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Robine H J Leeuwis
- Fish Physiology Laboratory, Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, NL, Canada
| | | | | | - Robert Gendron
- Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Kenneth Kao
- Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Jillian Westcott
- Fisheries and Marine Institute, Memorial University of Newfoundland, St. John's, NL, Canada
| | - A Kurt Gamperl
- Fish Physiology Laboratory, Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Javier Santander
- Marine Microbial Pathogenesis and Vaccinology Laboratory, Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, NL, Canada.
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