Protective efficacy and immune responses induced by a DNA vaccine encoding codon-optimized PPA1 against Photobacterium damselae subsp. piscicida in Japanese flounder

Kato, Go; Yamashita, Kozue; Kondo, Hidehiro; Hirono, Ikuo

doi:10.1016/j.vaccine.2015.01.011

“…To date, cellular immune responses induced by DNA vaccines in fish models have largely been investigated via transcriptional responses. This has been due to the lack of availability of antibodies for markers of specific T-cell subpopulations (50)(51)(52)(53). Recently, with the production of specific antibodies for fish T lymphocytes, it has become possible to investigate cellular immune responses at the translational level.…”

Section: Discussionmentioning

confidence: 99%

A DNA Vaccine Encoding the VAA Gene of Vibrio anguillarum Induces a Protective Immune Response in Flounder

Xing

¹

,

Xu

²

,

Tang

³

et al. 2019

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Vibrio anguillarum is a pathogenic bacterium that infects flounder resulting in significant losses in the aquaculture industry. The VAA protein previously identified in flounder is associated with a role in immune protection within these fish. In the present study, a recombinant DNA plasmid encoding the VAA gene of V. anguillarum was constructed and its potential as a DNA vaccine, to prevent the infection of V. anguillarum in flounder fish, investigated. We verified the expression of the VAA protein both in vitro in cell lines and in vivo in flounder fish. The protective effects of pcDNA3.1-VAA (pVAA) were analyzed by determination of the percentage of sIgM+, CD4-1+, CD4-2+, CD8β+ lymphocytes, and the production of VAA-specific antibodies in flounder following their immunization with the DNA vaccine. Histopathological changes in immune related tissues, bacterial load, and relative percentage survival rates of flounder post-challenge with V. anguillarum, were all investigated to assess the efficacy of the pVAA DNA vaccine candidate. Fish intramuscularly immunized with pVAA showed a significant increase in CD4-1+, CD4-2+, and CD8β+ T lymphocytes at days 9, 11, and 14 post-vaccination, reaching peak T-cell levels at days 11 or 14 post-immunization. The percentage of sIgM+ lymphocytes reached peak levels at weeks 4–5 post-immunization. Specific anti-V. anguillarum or anti-rVAA antibodies were induced in inoculated fish at days 28–35 post-immunization. The liver of vaccinated flounder exhibited only slight histopathological changes compared with a significant pathology observed in control immunized fish. Additionally, a lower bacterial burden in the liver, spleen, and kidney were observed in pVAA protected fish in response to bacterial challenge, compared with pcDNA3.1 vector control injected fish. Moreover, the pVAA vaccine confers a relative percentage survival of 50.00% following V. anguillarum infection. In summary, this is the first study indicating an initial induction of the T lymphocyte response, followed by B lymphocyte induction of specific antibodies as a result of DNA immunization of flounder. This signifies the important potential of pVAA as a DNA vaccine candidate for the control of V. anguillarum infection.

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“…The cumulative mortality of the challenged fish was recorded daily for 2 weeks. The efficacy of vaccination was evaluated by the relative per cent survival (RPS) at the end of the experiment, which was calculated as RPS = [1 − (% mortality of vaccinated fish/% mortality of control fish)] × 100 (Kato, Yamashita, Kondo, & Hirono, ).…”

Section: Methodsmentioning

confidence: 99%

“…challenged fish was recorded daily for 2 weeks. The efficacy of vaccination was evaluated by the relative per cent survival (RPS) at the end of the experiment, which was calculated as RPS = [1 À (% mortality of vaccinated fish/% mortality of control fish)] 9 100(Kato, Yamashita, Kondo, & Hirono, 2015).2.10 | Cross-reactivities of V. harveyi rOmpK-OmpU antiseraThe V. harveyi rOmpK-OmpU vaccine induced greater immune responses and offered higher protection to groupers infected with V. harveyi; thus, the fusion protein was further examined for crossreactivities towards heterologous vibriosis pathogens, V. parahaemolyticus (Va strain) and V. alginolyticus (Va strain), isolated from diseased groupers.…”

mentioning

confidence: 99%

Enhanced immune responses and effectiveness of refined outer membrane protein vaccines against Vibrio harveyi in orange‐spotted grouper (Epinephelus coioides)

Nguyen

¹

,

Nguyen

²

,

Chen

³

et al. 2018

Journal of Fish Diseases

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Vibriosis is a severe infection occurring in many commercially important marine fish species. In this study, vaccines containing Vibrio harveyi recombinant outer membrane protein K (rOmpK), outer membrane protein U (rOmpU) and rOmpK-OmpU fusion protein in addition to the metabolizable Montanide ISA 763 A VG adjuvant were developed and evaluated in the orange-spotted grouper. The results indicate that recombinant V. harveyi protein-based vaccines resulted in a remarkably higher expression of IL-1β and IL-8 at 24 hr, and greater antibody production, as early as 2 weeks postimmunization. Notably, enhanced immune responses and significant protective efficacy against V. harveyi infections were observed in the fusion protein vaccine-injected fishes with relative per cent survival value of 81.8%. Additionally, the rOmpK-OmpU antisera presented a high bactericidal effect on not only V. harveyi, but also Vibrio parahaermolyticus and Vibrio alginolyticus. Our results demonstrated that the fusion protein rOmpK-OmpU was an effective vaccine candidate that exhibited potentially great versatility for controlling vibrio infections.

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“…This strategy has been successfully employed in experimental vaccines against P. damselae subsp. piscicida in flounder in Japan [ 16 ]. However, identification of candidate DNA vaccine immunogens relies heavily on the availability of accurate genetic information.…”

Section: Introductionmentioning

confidence: 99%

Complete, closed and curated genome sequences of Photobacterium damselae subsp. piscicida isolates from Australia indicate mobilome-driven localized evolution and novel pathogenicity determinants

Baseggio

¹

,

Silayeva

²

,

Buller

³

et al. 2021

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Despite the recent advances in sequencing technologies, the complete assembly of multi-chromosome genomes of the Vibrionaceae , often containing several plasmids, remains challenging. Using a combination of Oxford Nanopore MinION long reads and short Illumina reads, we fully sequenced, closed and curated the genomes of two strains of a primary aquatic pathogen Photobacterium damselae subsp. piscicida isolated in Australia. These are also the first genome sequences of P. damselae subsp. piscicida isolated in Oceania and, to our knowledge, in the Southern hemisphere. We also investigated the phylogenetic relationships between Australian and overseas isolates, revealing that Australian P. damselae subsp. piscicida are more closely related to the Asian and American strains rather than to the European ones. We investigated the mobilome and present new evidence showing that a host specialization process and progressive adaptive evolution to fish are ongoing in P. damselae subsp. piscicida , and are largely mediated by transposable elements, predominantly in chromosome 2, and by plasmids. Finally, we identified two novel potential virulence determinants in P. damselae subsp. piscicida – a chorismate mutase gene, which is ubiquitously retained and co-localized with the AIP56 apoptogenic toxin-encoding gene on the pPHDP10 plasmid, and transfer-messenger RNA gene ssrA located on the main chromosome, homologous to a critical-to-virulence determinant in Yersinia pseudotuberculosis . Our study describes, to our knowledge, the only fully closed and manually curated genomes of P. damselae subsp. piscicida available to date, offering new insights into this important fish pathogen and its evolution.

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Protective efficacy and immune responses induced by a DNA vaccine encoding codon-optimized PPA1 against Photobacterium damselae subsp. piscicida in Japanese flounder

Cited by 20 publications

References 41 publications

A DNA Vaccine Encoding the VAA Gene of Vibrio anguillarum Induces a Protective Immune Response in Flounder

A DNA Vaccine Encoding the VAA Gene of Vibrio anguillarum Induces a Protective Immune Response in Flounder

Enhanced immune responses and effectiveness of refined outer membrane protein vaccines against Vibrio harveyi in orange‐spotted grouper (Epinephelus coioides)

Complete, closed and curated genome sequences of Photobacterium damselae subsp. piscicida isolates from Australia indicate mobilome-driven localized evolution and novel pathogenicity determinants

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