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Soto-Dávila M, Rodríguez-Cornejo T, Benito VW, Rodríguez-Ramos T, Mahoney G, Supinski R, Heath G, Dang X, Valle FM, Hurtado C, Llanco LA, Serrano-Martinez E, Dixon B. Innate and adaptive immune response of Rainbow trout (Oncorhynchus mykiss) naturally infected with Yersinia ruckeri. FISH & SHELLFISH IMMUNOLOGY 2024; 151:109742. [PMID: 38960109 DOI: 10.1016/j.fsi.2024.109742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2024] [Revised: 06/26/2024] [Accepted: 07/01/2024] [Indexed: 07/05/2024]
Abstract
Rainbow trout is an important fish species for Peruvian artisanal aquaculture, comprising over 60 % of the total aquaculture production. However, their industry has been highly affected by several bacterial agents such as Yersinia ruckeri. This pathogen is the causative agent of Enteric Redmouth Disease, and causes high mortality in fingerlings and chronic infection in adult rainbow trout. To date, the immune response of rainbow trout against Y. ruckeri has been well studied in laboratory-controlled infection studies (i.e. intraperitoneal infection, bath immersion), however, the immune response during natural infection has not been explored. To address this, in this study, 35 clinically healthy O. mykiss without evidence of lesions or changes in behavior and 32 rainbow trout naturally infected by Y. ruckeri, were collected from semi-intensive fish farms located in the Central Highlands of Peru. To evaluate the effect on the immune response, RT-qPCR, western blotting, and ELISA were conducted using head kidney, spleen, and skin tissues to evaluate the relative gene expression and protein levels. Our results show a significant increase in the expression of the pro-inflammatory cytokines il1b, tnfa, and il6, as well as ifng in all three tissues, as well as increases in IL-1β and IFN-γ protein levels. The endogenous pathway of antigen presentation showed to play a key role in defense against Y. ruckeri, due to the upregulation of mhc-I, tapasin, and b2m transcripts, and the significant increase of Tapasin protein levels in infected rainbow trout. None of the genes associated with the exogenous pathway of antigen presentation showed a significant increase in infected fish, suggesting that this pathway is not involved in the response against this intracellular pathogen. Finally, the transcripts of immunoglobulins IgM and IgT did not show a modulation, nor were the protein levels evaluated in this study.
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Affiliation(s)
- Manuel Soto-Dávila
- Department of Biology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada; Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, C1A 4P3, Canada
| | - Tania Rodríguez-Cornejo
- Department of Biology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada; Faculty of Veterinary Medicine and Zootechnics, Universidad Peruana Cayetano Heredia, Lima, Peru
| | | | | | - Gracen Mahoney
- Department of Biology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
| | - Rochelle Supinski
- Department of Biology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
| | - George Heath
- Department of Biology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
| | - Xiaoqing Dang
- Department of Biology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
| | - Fernando Mesías Valle
- CITEacuícola Pesquero Ahuashiyacu, Instituto Tecnológico de la Producción, La Banda de Shilcayo CP, 22200, San Martín, Peru
| | - Carmen Hurtado
- Faculty of Veterinary Medicine and Zootechnics, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Luis A Llanco
- School of Human Medicine, Universidad Privada San Juan Bautista, Apartado, Chincha, 15067, Peru
| | - Enrique Serrano-Martinez
- Faculty of Veterinary Medicine and Zootechnics, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Brian Dixon
- Department of Biology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada.
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Méndez LR, Soto-Dávila M, Wong-Benito V, Rodríguez-Ramos T, Carpio Y, Estrada MP, Dixon B. PACAP binds conserved receptors and modulates cytokine gene expression and protein secretion in trout cell lines. FISH & SHELLFISH IMMUNOLOGY 2024; 151:109738. [PMID: 38971350 DOI: 10.1016/j.fsi.2024.109738] [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: 04/27/2024] [Revised: 06/27/2024] [Accepted: 06/30/2024] [Indexed: 07/08/2024]
Abstract
Antimicrobial peptides (AMPs) are an alternative to antibiotics for treatment and prevention of infections with a lower risk of bacterial resistance. Pituitary adenylate cyclase activating polypeptide (PACAP) is an outstanding AMP with versatile effects including antimicrobial activity and modulation of immune responses. The objective of this research was to study PACAP immunomodulatory effect on rainbow trout cell lines infected with Aeromonas salmonicida. PACAP from Clarias gariepinus (PACAP1) and a modified PACAP (PACAP5) were tested. RT-qPCR results showed that il1b and il8 expression in RTgutGC was significantly downregulated while tgfb expression was upregulated after PACAP treatment. Importantly, the concentration of IL-1β and IFN-γ increased in the conditioned media of RTS11 cells incubated with PACAP1 and exposed to A. salmonicida. There was a poor correlation between gene expression and protein concentration, suggesting a stimulation of the translation of IL-1β protein from previously accumulated transcripts or the cleavage of accumulated IL-1β precursor. In-silico studies of PACAP-receptor interactions showed a turn of the peptide characteristic of PACAP-PAC1 interaction, correlated with the higher number of interactions observed with this specific receptor, which is also in agreement with the higher PACAP specificity described for PAC1 compared to VPAC1 and VPACA2. Finally, the in silico analysis revealed nine amino acids related to the PACAP receptor-associated functionality.
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Affiliation(s)
- Laura Rivera Méndez
- Department of Biology, University of Waterloo, 200 University Ave W., Waterloo, ON, Canada
| | - Manuel Soto-Dávila
- Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, C1A 4P3, Canada
| | - Valentina Wong-Benito
- Department of Biology, University of Waterloo, 200 University Ave W., Waterloo, ON, Canada
| | - Tania Rodríguez-Ramos
- Department of Biology, University of Waterloo, 200 University Ave W., Waterloo, ON, Canada
| | - Yamila Carpio
- Animal Biotechnology Department, Center for Genetic Engineering and Biotechnology (CIGB), P.O. Box 6162, Havana, 10600, Cuba
| | - Mario Pablo Estrada
- Animal Biotechnology Department, Center for Genetic Engineering and Biotechnology (CIGB), P.O. Box 6162, Havana, 10600, Cuba
| | - Brian Dixon
- Department of Biology, University of Waterloo, 200 University Ave W., Waterloo, ON, Canada.
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Méndez LR, Rodríguez-Cornejo T, Rodríguez-Ramos T, Al-Hussinee L, Velázquez J, Campbell JH, Carpio Y, Estrada MP, Dixon B. PACAP sequence modifications modulate the peptide antimicrobial activity against bacterial pathogens affecting aquaculture. FISH & SHELLFISH IMMUNOLOGY 2024; 148:109512. [PMID: 38499216 DOI: 10.1016/j.fsi.2024.109512] [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: 01/23/2024] [Revised: 03/05/2024] [Accepted: 03/15/2024] [Indexed: 03/20/2024]
Abstract
The global aquaculture industry has significant losses each year due to disease outbreaks. Antibiotics are one of the common methods to treat fish infections, but prolonged use can lead to the emergence of resistant strains. Aeromonas spp. Infections are a common and problematic disease in fish, and members of this genera can produce antibiotic resistant strains. Antimicrobial peptides (AMPs) have emerged as an alternative method to treat and prevent infections and pituitary adenylate cyclase activating polypeptide (PACAP) is a prominent member of this family. The objective of this research was to study PACAP's direct antimicrobial activity and its toxicity in fish cells. Four synthetic variants of the natural PACAP from Clarias gariepinus were tested in addition to the natural variant. The experimental results show a different antimicrobial activity against A. salmonicida and A. hydrophila of each PACAP variant, and for the first time show dependence on the culture broth used. Furthermore, the results suggest that the underlying mechanism of PACAP antimicrobial activity includes a bacterial membrane permeabilizing effect, classifying PACAP as a membrane disruptive AMP. This study also demonstrated that the five PACAP variants evaluated showed low toxicity in vitro, at concentrations relevant for in vivo applications. Therefore, PACAP could be a promising alternative to antibiotics in the aquaculture sector.
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Affiliation(s)
- Laura Rivera Méndez
- Department of Biology, University of Waterloo, 200 University Ave W., Waterloo, ON, Canada
| | | | - Tania Rodríguez-Ramos
- Department of Biology, University of Waterloo, 200 University Ave W., Waterloo, ON, Canada
| | - Lowia Al-Hussinee
- Department of Biology, University of Waterloo, 200 University Ave W., Waterloo, ON, Canada; Animal Health Laboratory, OVC, Guelph University, Canada
| | - Janet Velázquez
- Animal Biotechnology Department, Center for Genetic Engineering and Biotechnology (CIGB), P.O. Box 6162, Havana, 10600, Cuba
| | - James Hugh Campbell
- Department of Biology, University of Waterloo, 200 University Ave W., Waterloo, ON, Canada
| | - Yamila Carpio
- Animal Biotechnology Department, Center for Genetic Engineering and Biotechnology (CIGB), P.O. Box 6162, Havana, 10600, Cuba
| | - Mario Pablo Estrada
- Animal Biotechnology Department, Center for Genetic Engineering and Biotechnology (CIGB), P.O. Box 6162, Havana, 10600, Cuba
| | - Brian Dixon
- Department of Biology, University of Waterloo, 200 University Ave W., Waterloo, ON, Canada.
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Campbell JH, Dang X, Rodríguez-Ramos T, Carpio Y, Estrada MP, Dixon B. The effect of PACAP administration on LPS-induced cytokine expression in the Atlantic salmon SHK-1 cell line. FISH AND SHELLFISH IMMUNOLOGY REPORTS 2023; 5:100116. [PMID: 37753327 PMCID: PMC10518582 DOI: 10.1016/j.fsirep.2023.100116] [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: 08/18/2023] [Revised: 09/13/2023] [Accepted: 09/16/2023] [Indexed: 09/28/2023] Open
Abstract
Recent work has identified pituitary adenylate cyclase activating polypeptide (PACAP) as a potential antimicrobial and immune stimulating agent which may be suitable for use in aquaculture. However, its effects on teleost immunity are not well studied and may be significantly different than what has been observed in mammals. In this study we examined the effects of PACAP on the Atlantic salmon macrophage cell line SHK-1. PACAP was able to increase the expression of LPS-induced il-1β in at concentrations of 1 uM when administered 24h prior to LPS stimulation. Furthermore, concentrations as low as 40nM had an effect when administered both 24h prior and in tandem with LPS. PACAP was also capable of increasing the expression of il-1β and tnf-α in SHK-1 cells challenged with a low dose of heat-killed Flavobacterium columnare. We attempted to get a better understanding of the mechanism underlying this enhancement of il-1β expression by manipulating downstream signaling of PACAP with inhibitors of phosphodiesterase and phospholipase C activity. We found that inducing cAMP accumulation with phosphodiesterase inhibitors failed to recapitulate the effect of PACAP administration on LPS-mediated il-1β expression by PACAP, while use of a phospholipase C inhibitor caused a PACAP-like enhancement in LPS-mediated il-1β expression. Interestingly, the VPAC1 receptor inhibitor PG97-269, but not the PAC1 inhibitor max.d.4, also was capable of causing a PACAP-like enhancement in LPS-mediated il-1β expression. This suggests that fish do not utilize the PACAP receptors in the same manner as mammals, but that it still exerts an immunostimulatory effect that make it a good immunostimulant for use in aquaculture.
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Affiliation(s)
- James Hugh Campbell
- Department of Biology, University of Waterloo, 200 University Ave W, Waterloo, ON N2L 3G1
| | - Xiaoqing Dang
- Department of Biology, University of Waterloo, 200 University Ave W, Waterloo, ON N2L 3G1
| | - Tania Rodríguez-Ramos
- Department of Biology, University of Waterloo, 200 University Ave W, Waterloo, ON N2L 3G1
| | - Yamila Carpio
- Center for Genetic Engineering and Biotechnology, Avenida 31 No. 15802, Havana, Cuba
| | - Mario P. Estrada
- Center for Genetic Engineering and Biotechnology, Avenida 31 No. 15802, Havana, Cuba
| | - Brian Dixon
- Department of Biology, University of Waterloo, 200 University Ave W, Waterloo, ON N2L 3G1
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5
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Muñoz-Flores C, Roa FJ, Saavedra P, Fuentealba P, Starck MF, Ortega L, Montesino R, Valenzuela A, Astuya A, Parra N, González-Chavarría I, Sánchez O, Toledo JR, Acosta J. Immunomodulatory role of vasoactive intestinal peptide and ghrelin in Oncorhynchus mykiss. Heliyon 2023; 9:e23215. [PMID: 38149209 PMCID: PMC10750074 DOI: 10.1016/j.heliyon.2023.e23215] [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: 04/28/2023] [Revised: 11/21/2023] [Accepted: 11/29/2023] [Indexed: 12/28/2023] Open
Abstract
Neuropeptides are a group of peptides derived from precursor proteins synthesized in neuronal and nonneuronal cells. The classical functions of neuropeptides have been extensively studied in mammals, including neuromodulation in the central nervous system, molecular signaling in the peripheral nervous system, and immunomodulation associated mainly with anti-inflammatory activity. In contrast, in teleosts, studies of the immunomodulatory function of these neuropeptides are limited. In Oncorhynchus mykiss, vasoactive intestinal peptide (VIP) mRNA sequences have not been cloned, and the role of VIP in modulating the immune system has not been studied. Furthermore, in relation to other neuropeptides with possible immunomodulatory function, such as ghrelin, there are also few studies. Therefore, in this work, we performed molecular cloning, identification, and phylogenetic analysis of three VIP precursor sequences (prepro-VIP1, VIP2 and VIP3) in rainbow trout. In addition, the immunomodulatory function of both neuropeptides was evaluated in an in vitro model using the VIP1 sequence identified in this work and a ghrelin sequence already studied in O. mykiss. The results suggest that the prepro-VIP2 sequence has the lowest percentage of identity with respect to the other homologous sequences and is more closely related to mammalian orthologous sequences. VIP1 induces significant expression of both pro-inflammatory (IFN-γ, IL-1β) and anti-inflammatory (IL-10 and TGF-β) cytokines, whereas ghrelin only induces significant expression of proinflammatory cytokines such as IL-6 and TNF-α.
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Affiliation(s)
- Carolina Muñoz-Flores
- Laboratorio de Biotecnología y Biofármacos, Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Víctor Lamas 1290, P.O. Box 160-C, Concepción, Chile
| | - Francisco J. Roa
- Laboratorio de Biotecnología y Biofármacos, Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Víctor Lamas 1290, P.O. Box 160-C, Concepción, Chile
| | - Paulina Saavedra
- Laboratorio de Biotecnología y Biofármacos, Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Víctor Lamas 1290, P.O. Box 160-C, Concepción, Chile
| | - Pablo Fuentealba
- Laboratorio de Biotecnología y Biofármacos, Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Víctor Lamas 1290, P.O. Box 160-C, Concepción, Chile
| | - María F. Starck
- Laboratorio de Biotecnología y Biofármacos, Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Víctor Lamas 1290, P.O. Box 160-C, Concepción, Chile
| | - Leonardo Ortega
- Laboratorio de Biotecnología y Biofármacos, Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Víctor Lamas 1290, P.O. Box 160-C, Concepción, Chile
| | - Raquel Montesino
- Laboratorio de Biotecnología y Biofármacos, Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Víctor Lamas 1290, P.O. Box 160-C, Concepción, Chile
| | - Ariel Valenzuela
- Laboratorio de Piscicultura y Patología Acuática, Departamento de Oceanografía, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Victor Lamas 1290, P.O. Box 160-C, Concepción, Chile
| | - Allisson Astuya
- Laboratorio de Genómica Marina y Cultivo Celular, Departamento de Oceanografía y COPAS Sur-Austral, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Victor Lamas 1290, P.O. Box 160-C, Concepción, Chile
| | - Natalie Parra
- Laboratorio de Biotecnología y Biofármacos, Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Víctor Lamas 1290, P.O. Box 160-C, Concepción, Chile
| | - Iván González-Chavarría
- Laboratorio de Biotecnología y Biofármacos, Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Víctor Lamas 1290, P.O. Box 160-C, Concepción, Chile
| | - Oliberto Sánchez
- Laboratorio de Biofármacos Recombinantes, Departamento de Farmacología, Facultad de Ciencias Biológicas, Universidad de Concepción, Víctor Lamas 1290, P.O. Box 160-C, Concepción, Chile
| | - Jorge R. Toledo
- Laboratorio de Biotecnología y Biofármacos, Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Víctor Lamas 1290, P.O. Box 160-C, Concepción, Chile
| | - Jannel Acosta
- Laboratorio de Biotecnología y Biofármacos, Departamento de Fisiopatología, Facultad de Ciencias Biológicas, Universidad de Concepción, Víctor Lamas 1290, P.O. Box 160-C, Concepción, Chile
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6
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Frenette AP, Rodríguez-Ramos T, Zanuzzo F, Ramsay D, Semple SL, Soullière C, Rodríguez-Cornejo T, Heath G, McKenzie E, Iwanczyk J, Bruder M, Aucoin MG, Gamperl AK, Dixon B. Expression of Interleukin-1β protein in vitro,exvivo and in vivo salmonid models. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2023; 147:104767. [PMID: 37406840 DOI: 10.1016/j.dci.2023.104767] [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: 05/07/2023] [Revised: 06/30/2023] [Accepted: 07/01/2023] [Indexed: 07/07/2023]
Abstract
Interleukin-1β (IL-1β) is one of the first cytokines expressed during immune responses, and its levels are affected by many factors, including stress. To date, it has only been possible to measure IL-1β transcript (mRNA) expression quantitatively in fish using qPCR. This is because previous studies that measured IL-1β protein concentrations in these taxa used western blotting, which only provides qualitative data. To advance our knowledge of fish IL-1β biology, and because post-translational processing plays a critical role in the activation of this molecule, we developed a quantitative enzyme-linked immunosorbent assay (ELISA) to accurately measure the concentration of IL-1β protein in several cell cultures and in vivo in salmonids. We compared changes in IL-1β protein levels to the expression of its mRNA. The developed ELISA was quite sensitive and has a detection limit of 12.5 pg/mL. The tools developed, and information generated through this research, will allow for a more accurate and complete understanding of IL-1β's role in the immune response of salmonids.The assay described here has the potential to significantly advance our ability to assess fish health and immune status.
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Affiliation(s)
- Aaron P Frenette
- Department of Biology, University of Waterloo, Waterloo, ON, Canada
| | | | - Fabio Zanuzzo
- Department of Ocean Sciences, Memorial University of Newfoundland and Labrador, St. John's, NL, Canada; Universidade Estadual Paulista - UNESP, Centro de Aquicultura da UNESP, Faculdade de Ciências Agrárias e Veterinárias, Via de Acesso Prof. Paulo Donato Castellane, Jaboticabal, CEP, 14884-900, SP, Brazil
| | - Devyn Ramsay
- Department of Ocean Sciences, Memorial University of Newfoundland and Labrador, St. John's, NL, Canada
| | - Shawna L Semple
- Department of Biology, University of Waterloo, Waterloo, ON, Canada
| | - Cheryl Soullière
- Department of Biology, University of Waterloo, Waterloo, ON, Canada
| | | | - George Heath
- Department of Biology, University of Waterloo, Waterloo, ON, Canada
| | - Emily McKenzie
- Department of Biology, University of Waterloo, Waterloo, ON, Canada
| | | | - Mark Bruder
- Department of Chemical Engineering, University of Waterloo, Waterloo, ON, Canada
| | - Marc G Aucoin
- Department of Chemical Engineering, University of Waterloo, Waterloo, ON, Canada
| | - A Kurt Gamperl
- Department of Ocean Sciences, Memorial University of Newfoundland and Labrador, St. John's, NL, Canada
| | - Brian Dixon
- Department of Biology, University of Waterloo, Waterloo, ON, Canada.
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7
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Velázquez J, Rodríguez-Cornejo T, Rodríguez-Ramos T, Pérez-Rodríguez G, Rivera L, Campbell JH, Al-Hussinee L, Carpio Y, Estrada MP, Dixon B. New Evidence for the Role of Pituitary Adenylate Cyclase-Activating Polypeptide as an Antimicrobial Peptide in Teleost Fish. Antibiotics (Basel) 2023; 12:1484. [PMID: 37887185 PMCID: PMC10604671 DOI: 10.3390/antibiotics12101484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 09/21/2023] [Accepted: 09/23/2023] [Indexed: 10/28/2023] Open
Abstract
Pituitary Adenylate Cyclase-Activating Polypeptide (PACAP) is a multifunctional neuropeptide that is widely distributed and conserved across species. We have previously shown that in teleost fish, PACAP not only possesses direct antimicrobial properties but also immunomodulatory effects against the bacterial pathogens Flavobacterium psychrophilum and Pseudomonas aeruginosa using in vitro and in vivo experiments. These previous results suggest PACAP can be used as an alternative to antibiotics to prevent and/or treat bacterial infections in the aquaculture industry. To accomplish this goal, more studies are needed to better understand the effect of PACAP on pathogens affecting fish in live infections. In the present study, the transcripts PACAP, PRP/PACAP, and VPAC2 receptor were examined in rainbow trout (Oncorhynchus mykiss) naturally infected with Yersinia ruckeri, which exhibited an increase in their expression in the spleen when compared to healthy fish. Synthetic Clarias gariepinus PACAP-38 has direct antimicrobial activity on Y. ruckeri and inhibits up to 60% of the bacterial growth when the peptide is at concentrations between 50 and 100 µM in TSB. The growth inhibition increased up to 90% in the presence of 12.5 µM of PACAP-38 when salt-free LB broth was used instead of TSB. It was also found to inhibit Y. ruckeri growth in a dose-dependent manner when the rainbow trout monocyte/macrophage-like cell line (RTS11) was pre-treated with lower concentrations of the peptide (0.02 and 0.1 µM) before going through infection. Differential gene expression was analyzed in this in vitro model. Overall, the results revealed new evidence to support the role of PACAP as an antimicrobial and immunomodulatory peptide treatment in teleosts.
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Affiliation(s)
- Janet Velázquez
- Animal Biotechnology Department, Center for Genetic Engineering and Biotechnology (CIGB), P.O. Box 6162, Havana 10600, Cuba; (J.V.); (G.P.-R.)
| | - Tania Rodríguez-Cornejo
- Department of Biology, University of Waterloo, 200 University Ave W., Waterloo, ON N2L 3G1, Canada; (T.R.-C.); (T.R.-R.); (L.R.); (J.H.C.); (L.A.-H.)
| | - Tania Rodríguez-Ramos
- Department of Biology, University of Waterloo, 200 University Ave W., Waterloo, ON N2L 3G1, Canada; (T.R.-C.); (T.R.-R.); (L.R.); (J.H.C.); (L.A.-H.)
| | - Geysi Pérez-Rodríguez
- Animal Biotechnology Department, Center for Genetic Engineering and Biotechnology (CIGB), P.O. Box 6162, Havana 10600, Cuba; (J.V.); (G.P.-R.)
| | - Laura Rivera
- Department of Biology, University of Waterloo, 200 University Ave W., Waterloo, ON N2L 3G1, Canada; (T.R.-C.); (T.R.-R.); (L.R.); (J.H.C.); (L.A.-H.)
| | - James Hugh Campbell
- Department of Biology, University of Waterloo, 200 University Ave W., Waterloo, ON N2L 3G1, Canada; (T.R.-C.); (T.R.-R.); (L.R.); (J.H.C.); (L.A.-H.)
| | - Lowia Al-Hussinee
- Department of Biology, University of Waterloo, 200 University Ave W., Waterloo, ON N2L 3G1, Canada; (T.R.-C.); (T.R.-R.); (L.R.); (J.H.C.); (L.A.-H.)
| | - Yamila Carpio
- Animal Biotechnology Department, Center for Genetic Engineering and Biotechnology (CIGB), P.O. Box 6162, Havana 10600, Cuba; (J.V.); (G.P.-R.)
| | - Mario Pablo Estrada
- Animal Biotechnology Department, Center for Genetic Engineering and Biotechnology (CIGB), P.O. Box 6162, Havana 10600, Cuba; (J.V.); (G.P.-R.)
| | - Brian Dixon
- Department of Biology, University of Waterloo, 200 University Ave W., Waterloo, ON N2L 3G1, Canada; (T.R.-C.); (T.R.-R.); (L.R.); (J.H.C.); (L.A.-H.)
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8
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Kraus A, Garcia B, Ma J, Herrera KJ, Zwaka H, Harpaz R, Wong RY, Engert F, Salinas I. Olfactory detection of viruses shapes brain immunity and behavior in zebrafish. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.17.533129. [PMID: 37034630 PMCID: PMC10081220 DOI: 10.1101/2023.03.17.533129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Olfactory sensory neurons (OSNs) are constantly exposed to pathogens, including viruses. However, serious brain infection via the olfactory route rarely occurs. When OSNs detect a virus, they coordinate local antiviral immune responses to stop virus progression to the brain. Despite effective immune control in the olfactory periphery, pathogen-triggered neuronal signals reach the CNS via the olfactory bulb (OB). We hypothesized that neuronal detection of a virus by OSNs initiates neuroimmune responses in the OB that prevent pathogen invasion. Using zebrafish ( Danio rerio ) as a model, we demonstrate viral-specific neuronal activation of OSNs projecting into the OB, indicating that OSNs are electrically activated by viruses. Further, behavioral changes are seen in both adult and larval zebrafish after viral exposure. By profiling the transcription of single cells in the OB after OSNs are exposed to virus, we found that both microglia and neurons enter a protective state. Microglia and macrophage populations in the OB respond within minutes of nasal viral delivery followed decreased expression of neuronal differentiation factors and enrichment of genes in the neuropeptide signaling pathway in neuronal clusters. Pituitary adenylate-cyclase-activating polypeptide ( pacap ), a known antimicrobial, was especially enriched in a neuronal cluster. We confirm that PACAP is antiviral in vitro and that PACAP expression increases in the OB 1 day post-viral treatment. Our work reveals how encounters with viruses in the olfactory periphery shape the vertebrate brain by inducing antimicrobial programs in neurons and by altering host behavior.
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Guo H, Whitehouse L, Danzmann R, Dixon B. Effects of juvenile thermal preconditioning on the heat-shock, immune, and stress responses of rainbow trout upon a secondary thermal challenge. Comp Biochem Physiol A Mol Integr Physiol 2023; 280:111413. [PMID: 36893937 DOI: 10.1016/j.cbpa.2023.111413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 03/03/2023] [Accepted: 03/03/2023] [Indexed: 03/09/2023]
Abstract
Higher water temperatures and pathogens are both significant factors that negatively affect the welfare of teleost fish. In aquaculture, compared to natural populations, these problems are especially exacerbated, as the animals have relatively limited mobility, and the higher density promotes faster spread of infectious diseases. Because of the potential harm these stressors can inflict, methods that can limit the damage of these stressors are particularly valuable. As a method of interest, early-life thermal preconditioning of animals demonstrated some potential for effective improvements in thermotolerance. However, the potential effects of the method on the immune system via the heat-stress model have not been explored. In this experiment, juvenile-stage thermal preconditioned rainbow trout (Oncorhynchus mykiss) were subjected to a secondary thermal challenge, animals were collected and sampled at the time of lost equilibrium. The effects of preconditioning on the general stress response was assessed by measuring the plasma cortisol levels. In addition, we also examined hsp70 and hsc70 mRNA levels in the spleen and gill tissues, as well as IL-1β, IL-6, TNF-α, IFN-1, β2m, and MH class I transcripts via qRT-PCR. No changes in CTmax were observed between the preconditioned and control cohorts upon the second challenge. IL-1β and IL-6 transcripts were generally upregulated with increased temperature of the secondary thermal challenge, whereas IFN-1 transcripts were upregulated in the spleen, but downregulated in the gills, along with MH class I. The juvenile thermal preconditioning produced a series of changes in transcript levels for IL-1β, TNF-α, IFN-1, and hsp70 but the dynamics of these differences were inconsistent. Finally, analysis of plasma cortisol levels presented significantly lower cortisol levels in the pre-conditioned animals compared to the non-pre-conditioned control cohort.
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Affiliation(s)
- Huming Guo
- University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Lindy Whitehouse
- University of Waterloo, Waterloo, Ontario N2L 3G1, Canada. https://twitter.com/LindyWhitehouse
| | - Roy Danzmann
- University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Brian Dixon
- University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.
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10
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Deng F, Wang D, Chen F, Lu T, Li S. Molecular characterization and expression analysis of claudin-4-like in rainbow trout involved in Flavobacterium psychrophilum infection. FISH & SHELLFISH IMMUNOLOGY 2022; 130:244-251. [PMID: 36122640 DOI: 10.1016/j.fsi.2022.09.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Revised: 08/23/2022] [Accepted: 09/10/2022] [Indexed: 06/15/2023]
Abstract
The claudin family of proteins are pivotal components of tight junction (TJ) participating in the epithelial barrier function in fish. Our previous studies indicated that one of the claudins, claudin-4-like (OmCLDN4L) was differentially expressed in rainbow trout (Oncorhynchus mykiss) spleen post infection of Flavobacterium psychrophilum, which is the causative pathogen of bacterial coldwater disease (BCWD). However, little is known about the function of OmCLDN4L in rainbow trout against bacterial infection. In the present study, the OmCLDN4L was identified and functionally characterized from rainbow trout. The OmCLDN4L has an open reading frame (ORF) of 668 bp, encoding a 22.86 kDa four-transmembrane protein with function of bicellular tight junction and apical tight junction. OmCLDN4L has the highest similarity with CLDN28a, CLDN28b and CLDN30 in amino acid sequence. Phylogenetic analysis showed that all of CLDN4 and CLDN4-like from fish clustered together but diverged from their counterparts in mammals, with main differences lying in their N-terminus. RT-qPCR results indicated that OmCLDN4L was constitutively expressed in all tissues investigated under healthy conditions, primarily in mucus, liver, skin and intestine. The expression of OmCLDN4L in rainbow trout intestine was slightly down-regulated at day 1 while up-regulated at day 3 and day 7 post F. psychrophilum infection, with the similar profiling of CLDN30 and CLDN10e. The expression level of inflammatory cytokines TNF-α, IL4/13A, IL-6 and pattern recognition receptor TLR-2 showed the same trend with OmCLDN4L in the intestine at day 3 and day 7 post F. psychrophilum infection. Collectively, these findings demonstrate that OmCLDN4L participates in the immune response to bacterial infection, offering new insights into the molecular mechanism of intestinal barrier in rainbow trout against F. psychrophilum infection.
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Affiliation(s)
- Furong Deng
- College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, 201306, China; Key Laboratory of Aquatic Animal Diseases and Immune Technology of Heilongjiang Province, Heilongjiang River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Harbin, 150070, China
| | - Di Wang
- Key Laboratory of Aquatic Animal Diseases and Immune Technology of Heilongjiang Province, Heilongjiang River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Harbin, 150070, China
| | - Fuguang Chen
- Key Laboratory of Aquatic Animal Diseases and Immune Technology of Heilongjiang Province, Heilongjiang River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Harbin, 150070, China
| | - Tongyan Lu
- Key Laboratory of Aquatic Animal Diseases and Immune Technology of Heilongjiang Province, Heilongjiang River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Harbin, 150070, China
| | - Shaowu Li
- Key Laboratory of Aquatic Animal Diseases and Immune Technology of Heilongjiang Province, Heilongjiang River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Harbin, 150070, China.
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11
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Rodríguez A, Velázquez J, González L, Rodríguez-Ramos T, Dixon B, Miyares FH, Morales A, González O, Estrada MP, Carpio Y. PACAP modulates the transcription of TLR-1/TLR-5/MyD88 pathway genes and boosts antimicrobial defenses in Clarias gariepinus. FISH & SHELLFISH IMMUNOLOGY 2021; 115:150-159. [PMID: 34146673 DOI: 10.1016/j.fsi.2021.06.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 06/10/2021] [Accepted: 06/13/2021] [Indexed: 06/12/2023]
Abstract
Pituitary adenylate cyclase-activating polypeptide (PACAP) is a multifunctional neuropeptide that belongs to the secretin/glucagon/GHRH/VIP superfamily. Some of these molecules have antimicrobial activity and they are capable of stimulating the immune system. The present work studied the antibacterial and immunostimulatory activity of PACAP-38 from African catfish Clarias gariepinus against the Gram-negative bacterium Pseudomonas aeruginosa in an in vivo test. PACAP-38 improved antimicrobial activity of skin mucus molecules against P. aeruginosa. The peptide modulates the gene expression profile of TLR-1, TLR-5, MyD88, IL-1β, TNF-ɑ, IL-8, pardaxin, hepcidin and G/C-type lysozymes in skin, spleen and head kidney. The influenced exerted depended on the time after infection and tissue analyzed. This study provides the first evidence of a link between PACAP and antimicrobial peptides hepcidin and pardaxin. Our results suggest further use of PACAP as antimicrobial agent that could potentially be used to control disease in aquaculture.
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Affiliation(s)
- Alianet Rodríguez
- Veterinary Immunology Project, Animal Biotechnology Division, Center for Genetic Engineering and Biotechnology, Havana, Cuba
| | - Janet Velázquez
- Veterinary Immunology Project, Animal Biotechnology Division, Center for Genetic Engineering and Biotechnology, Havana, Cuba
| | - Luis González
- Veterinary Immunology Project, Animal Biotechnology Division, Center for Genetic Engineering and Biotechnology, Havana, Cuba
| | - Tania Rodríguez-Ramos
- Department of Biology, University of Waterloo, 200 University Ave W., Waterloo, ON, Canada
| | - Brian Dixon
- Department of Biology, University of Waterloo, 200 University Ave W., Waterloo, ON, Canada
| | - Fidel Herrera Miyares
- Veterinary Immunology Project, Animal Biotechnology Division, Center for Genetic Engineering and Biotechnology, Havana, Cuba
| | - Antonio Morales
- Veterinary Immunology Project, Animal Biotechnology Division, Center for Genetic Engineering and Biotechnology, Havana, Cuba
| | - Osmany González
- Veterinary Immunology Project, Animal Biotechnology Division, Center for Genetic Engineering and Biotechnology, Havana, Cuba
| | - Mario Pablo Estrada
- Veterinary Immunology Project, Animal Biotechnology Division, Center for Genetic Engineering and Biotechnology, Havana, Cuba.
| | - Yamila Carpio
- Veterinary Immunology Project, Animal Biotechnology Division, Center for Genetic Engineering and Biotechnology, Havana, Cuba.
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12
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Jiang R, Lu XJ, Lu JF, Chen J. Characterization of ayu (Plecoglossus altivelis) urocortin: The function of an endocrine factor in monocyte/macrophage regulation. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2021; 117:103978. [PMID: 33338518 DOI: 10.1016/j.dci.2020.103978] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 12/13/2020] [Accepted: 12/13/2020] [Indexed: 06/12/2023]
Abstract
Urocortin (UCN) is a hormone in the hypothalamic-pituitary-adrenal axis that is expressed in various immune cells. However, the function of teleost UCN in the immune system remains unclear. In this study, we cloned the cDNA sequence of UCN from ayu Plecoglossus altivelis (PaUCN). Sequence and phylogenetic tree analyses showed that PaUCN clustered within the fish UCN 1 group and was most related to the rainbow trout (Oncorhynchus mykiss) UCN. PaUCN was expressed in all tested tissues and its expression increased in the liver, spleen, head kidney, and gill upon Vibrio anguillarum infection. Mature PaUCN protein (mPaUCN) treatment affected the phagocytosis and bacterial killing of monocytes/macrophages (MO/MФ). mPaUCN reduced pro-inflammatory cytokine expression in MO/MФ, which was partially mediated via interaction with ayu interleukin-6. mPaUCN reduced bacterial load and increased the survival of V. anguillarum-infected ayu. Overall, UCN as an endocrine factor regulates the immune response of ayu after infection by activating MO/MФ, thus contributing to enhance fish survival.
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Affiliation(s)
- Rui Jiang
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo University, Ningbo, 315211, China; Laboratory of Biochemistry and Molecular Biology, School of Marine Sciences, Ningbo University, Ningbo, 315211, China; Key Laboratory of Applied Marine Biotechnology of Ministry of Education, Ningbo University, Ningbo, 315211, China
| | - Xin-Jiang Lu
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo University, Ningbo, 315211, China; Laboratory of Biochemistry and Molecular Biology, School of Marine Sciences, Ningbo University, Ningbo, 315211, China; Key Laboratory of Applied Marine Biotechnology of Ministry of Education, Ningbo University, Ningbo, 315211, China; Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology (Qingdao), China.
| | - Jian-Fei Lu
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo University, Ningbo, 315211, China; Laboratory of Biochemistry and Molecular Biology, School of Marine Sciences, Ningbo University, Ningbo, 315211, China; Key Laboratory of Applied Marine Biotechnology of Ministry of Education, Ningbo University, Ningbo, 315211, China
| | - Jiong Chen
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Ningbo University, Ningbo, 315211, China; Laboratory of Biochemistry and Molecular Biology, School of Marine Sciences, Ningbo University, Ningbo, 315211, China; Key Laboratory of Applied Marine Biotechnology of Ministry of Education, Ningbo University, Ningbo, 315211, China.
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13
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Lee EY, Chan LC, Wang H, Lieng J, Hung M, Srinivasan Y, Wang J, Waschek JA, Ferguson AL, Lee KF, Yount NY, Yeaman MR, Wong GCL. PACAP is a pathogen-inducible resident antimicrobial neuropeptide affording rapid and contextual molecular host defense of the brain. Proc Natl Acad Sci U S A 2021; 118:e1917623117. [PMID: 33372152 PMCID: PMC7817161 DOI: 10.1073/pnas.1917623117] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Defense of the central nervous system (CNS) against infection must be accomplished without generation of potentially injurious immune cell-mediated or off-target inflammation which could impair key functions. As the CNS is an immune-privileged compartment, inducible innate defense mechanisms endogenous to the CNS likely play an essential role in this regard. Pituitary adenylate cyclase-activating polypeptide (PACAP) is a neuropeptide known to regulate neurodevelopment, emotion, and certain stress responses. While PACAP is known to interact with the immune system, its significance in direct defense of brain or other tissues is not established. Here, we show that our machine-learning classifier can screen for immune activity in neuropeptides, and correctly identified PACAP as an antimicrobial neuropeptide in agreement with previous experimental work. Furthermore, synchrotron X-ray scattering, antimicrobial assays, and mechanistic fingerprinting provided precise insights into how PACAP exerts antimicrobial activities vs. pathogens via multiple and synergistic mechanisms, including dysregulation of membrane integrity and energetics and activation of cell death pathways. Importantly, resident PACAP is selectively induced up to 50-fold in the brain in mouse models of Staphylococcus aureus or Candida albicans infection in vivo, without inducing immune cell infiltration. We show differential PACAP induction even in various tissues outside the CNS, and how these observed patterns of induction are consistent with the antimicrobial efficacy of PACAP measured in conditions simulating specific physiologic contexts of those tissues. Phylogenetic analysis of PACAP revealed close conservation of predicted antimicrobial properties spanning primitive invertebrates to modern mammals. Together, these findings substantiate our hypothesis that PACAP is an ancient neuro-endocrine-immune effector that defends the CNS against infection while minimizing potentially injurious neuroinflammation.
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Affiliation(s)
- Ernest Y Lee
- Department of Bioengineering, University of California, Los Angeles, CA 90095
- UCLA-Caltech Medical Scientist Training Program, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095
| | - Liana C Chan
- Lundquist Institute for Biomedical Innovation, Harbor-UCLA Medical Center, Torrance, CA 90509
- Division of Molecular Medicine, Los Angeles County, Harbor-UCLA Medical Center, Torrance, CA 90509
- Division of Infectious Diseases, Los Angeles County, Harbor-UCLA Medical Center, Torrance, CA 90509
| | - Huiyuan Wang
- Lundquist Institute for Biomedical Innovation, Harbor-UCLA Medical Center, Torrance, CA 90509
- Division of Molecular Medicine, Los Angeles County, Harbor-UCLA Medical Center, Torrance, CA 90509
| | - Juelline Lieng
- Department of Bioengineering, University of California, Los Angeles, CA 90095
| | - Mandy Hung
- Department of Bioengineering, University of California, Los Angeles, CA 90095
| | - Yashes Srinivasan
- Department of Bioengineering, University of California, Los Angeles, CA 90095
| | - Jennifer Wang
- Department of Bioengineering, University of California, Los Angeles, CA 90095
| | - James A Waschek
- Semel Institute for Neuroscience and Human Behavior, Intellectual Development and Disabilities Research Center, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | - Andrew L Ferguson
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637
| | - Kuo-Fen Lee
- Peptide Biology Laboratories, Salk Institute for Biological Studies, La Jolla, CA 92037
| | - Nannette Y Yount
- Lundquist Institute for Biomedical Innovation, Harbor-UCLA Medical Center, Torrance, CA 90509
- Division of Molecular Medicine, Los Angeles County, Harbor-UCLA Medical Center, Torrance, CA 90509
| | - Michael R Yeaman
- Division of Molecular Medicine, Los Angeles County, Harbor-UCLA Medical Center, Torrance, CA 90509;
- Division of Infectious Diseases, Los Angeles County, Harbor-UCLA Medical Center, Torrance, CA 90509
- Semel Institute for Neuroscience and Human Behavior, Intellectual Development and Disabilities Research Center, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | - Gerard C L Wong
- Department of Bioengineering, University of California, Los Angeles, CA 90095;
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095
- California NanoSystems Institute, University of California, Los Angeles, CA 90095
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14
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Semple SL, Dixon B. Salmonid Antibacterial Immunity: An Aquaculture Perspective. BIOLOGY 2020; 9:E331. [PMID: 33050557 PMCID: PMC7599743 DOI: 10.3390/biology9100331] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 10/07/2020] [Accepted: 10/08/2020] [Indexed: 02/08/2023]
Abstract
The aquaculture industry is continuously threatened by infectious diseases, including those of bacterial origin. Regardless of the disease burden, aquaculture is already the main method for producing fish protein, having displaced capture fisheries. One attractive sector within this industry is the culture of salmonids, which are (a) uniquely under pressure due to overfishing and (b) the most valuable finfish per unit of weight. There are still knowledge gaps in the understanding of fish immunity, leading to vaccines that are not as effective as in terrestrial species, thus a common method to combat bacterial disease outbreaks is the use of antibiotics. Though effective, this method increases both the prevalence and risk of generating antibiotic-resistant bacteria. To facilitate vaccine design and/or alternative treatment efforts, a deeper understanding of the teleost immune system is essential. This review highlights the current state of teleost antibacterial immunity in the context of salmonid aquaculture. Additionally, the success of current techniques/methods used to combat bacterial diseases in salmonid aquaculture will be addressed. Filling the immunology knowledge gaps highlighted here will assist in reducing aquaculture losses in the future.
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Affiliation(s)
| | - Brian Dixon
- Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1, Canada;
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15
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Velázquez J, Pérez G, Semple SL, Rodríguez-Ramos T, Díaz-Rosales P, Ordás MDC, Lugo JM, Dixon B, Tafalla C, Estrada MP, Carpio Y. First in vivo evidence of pituitary adenylate cyclase-activating polypeptide antiviral activity in teleost. FISH & SHELLFISH IMMUNOLOGY 2020; 103:58-65. [PMID: 32334130 DOI: 10.1016/j.fsi.2020.04.038] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 04/02/2020] [Accepted: 04/17/2020] [Indexed: 06/11/2023]
Abstract
Pituitary adenylate cyclase-activating polypeptide (PACAP) is a multifunctional neuropeptide belonging to the glucagon/secretin superfamily. In teleost fish, PACAP has been demonstrated to have an immunomodulatory role. Although previous studies have shown that viral/bacterial infections can influence the transcription of PACAP splicing variants and associated receptors in salmonids, the antiviral activity of PACAP has never been studied in teleost. Thus, in the present work, we investigated in vitro the influence of synthetic Clarias gariepinus PACAP-38 on the transcription of genes related to viral immunity using the rainbow trout monocyte/macrophage-like cell line RTS11 as a model. Positive transcriptional modulation of interferon gamma (IFNγ), interferon alpha (FNα1,2), interleukin 8 (IL-8), Mx and Toll-like receptor 3 (TLR3) genes was found in a dose and time dependent manner. We also explored how a pre-treatment with PACAP could enhance antiviral immune response using poly (I:C) as viral mimic. Interferons and IL-8 transcription levels were enhanced when PACAP was added 24 h previous to poly (I:C) exposure. With these evidences, we tested in vivo how PACAP administration by immersion bath affected the survival of rainbow trout fry to a challenge with viral hemorrhagic septicemia virus (VHSV). After challenge, PACAP-treated fish had increased survival compared to non-treated/challenge fish. Furthermore, PACAP was able to decrease the viral load in spleen/kidney and stimulate the transcription of IFNs and Mx when compared to untreated infected fish. Altogether, the results of this work provide valuable insights regarding the role of teleost PACAP in antiviral immunity and point to a potential application of this peptide to reduce the impact of viral infections in aquaculture.
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Affiliation(s)
- Janet Velázquez
- Veterinary Immunology Project, Animal Biotechnology Division, Center for Genetic Engineering and Biotechnology, Havana, Cuba
| | - Geysi Pérez
- Veterinary Immunology Project, Animal Biotechnology Division, Center for Genetic Engineering and Biotechnology, Havana, Cuba
| | - Shawna L Semple
- Department of Biology, University of Waterloo, 200 University Ave W., Waterloo, ON, Canada
| | - Tania Rodríguez-Ramos
- Department of Biology, University of Waterloo, 200 University Ave W., Waterloo, ON, Canada
| | - Patricia Díaz-Rosales
- Fish Immunology and Pathology Group, Animal Health Research Center (CISA-INIA), Valdeolmos, 28130, Madrid, Spain
| | - María Del Camino Ordás
- Fish Immunology and Pathology Group, Animal Health Research Center (CISA-INIA), Valdeolmos, 28130, Madrid, Spain
| | - Juana María Lugo
- Veterinary Immunology Project, Animal Biotechnology Division, Center for Genetic Engineering and Biotechnology, Havana, Cuba
| | - Brian Dixon
- Department of Biology, University of Waterloo, 200 University Ave W., Waterloo, ON, Canada
| | - Carolina Tafalla
- Fish Immunology and Pathology Group, Animal Health Research Center (CISA-INIA), Valdeolmos, 28130, Madrid, Spain.
| | - Mario Pablo Estrada
- Veterinary Immunology Project, Animal Biotechnology Division, Center for Genetic Engineering and Biotechnology, Havana, Cuba.
| | - Yamila Carpio
- Veterinary Immunology Project, Animal Biotechnology Division, Center for Genetic Engineering and Biotechnology, Havana, Cuba.
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16
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Semple SL, Bols NC, Lumsden JS, Dixon B. Understanding the pathogenesis of Flavobacterium psychrophilum using the rainbow trout monocyte/macrophage-like cell line, RTS11, as an infection model. Microb Pathog 2019; 139:103910. [PMID: 31809795 DOI: 10.1016/j.micpath.2019.103910] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 11/28/2019] [Accepted: 12/02/2019] [Indexed: 02/05/2023]
Abstract
The life cycle of Flavobacterium psychrophilum (Fp), the causative agent of bacterial coldwater disease (BCWD) and rainbow trout fry syndrome (RTFS), appears to involve interactions with spleen and head kidney macrophages. To develop an in vitro model for studying this, F. psychrophilum was incubated with a rainbow trout splenic monocyte/macrophage-like cell line (RTS11) and fundamental macrophage functions evaluated. The animal cell basal medium, L15, supplemented with bovine serum (FBS) supports RTS11 maintenance, and surprisingly, L15 with 2% FBS (L15/FBS) also supported F. psychrophilum growth. L15/FBS in which the bacteria had been grown is referred to as F. psychrophilum conditioned medium (FpCM). Adding FpCM to RTS11 cultures caused a small, yet significant, percentage of cells to die, many cells to become more diffuse, and phagocytosis to be temporarily reduced. FpCM also significantly stimulated transcript expression for pro-inflammatory cytokines (IL-1β, TNFα and IL-6) and the anti-inflammatory cytokine (IL-10) after one day of exposure but this upregulation rapidly declined over time. Adding live F. psychrophilum to RTS11 cultures also altered the cellular morphology and stimulated cytokine expression more profoundly than FpCM. Additionally, the phagocytic activity of RTS11 was also significantly impaired by live F. psychrophilum, but not to the same extent as when exposed to FpCM. Adding heat-killed bacteria to RTS11 cultures elicited few changes. These bacteria/RTS11 co-cultures should be useful for gaining a deeper understanding of the pathogenesis of F. psychrophilum and may aid in the development of effective measures to prevent infection and spread of this troublesome disease.
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Affiliation(s)
- Shawna L Semple
- University of Waterloo, Department of Biology, Waterloo, Canada
| | - Niels C Bols
- University of Waterloo, Department of Biology, Waterloo, Canada
| | - John S Lumsden
- University of Guelph, Ontario Veterinary College, Department of Pathobiology, Guelph, Canada
| | - Brian Dixon
- University of Waterloo, Department of Biology, Waterloo, Canada.
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