Turbot is one of the most important species for the aquaculture sector in Galicia and the sequencing of its DNA by the Immunology and Genomics Group of the Marine Research Institute in 2016 was a major step forward in optimizing its production. Now, the thesis of the researcher of this group, Patricia Pereiro, within the framework of the Doctoral Program in Marine Sciences, Technology and Management of Do*Mar advances the knowledge of the antiviral immune response and the resistance of turbot to its main virus, viral hemorrhagic septicemia (VHSV). In addition, the scientist also took a further step in terms of methods to combat it, designing the first DNA vaccine that encodes the G glycoprotein of VHSV.
The thesis, with international mention and directed by Beatriz Novoa and Antonio Figueras, was defended at the Institute of Marine Research, being the first doctoral thesis presented at a CSIC center in Galicia. The research group to which the doctoral student belongs has been developing research on turbot for more than two decades.
The thesis: context, objectives and results
“Turbot has a high commercial value, especially in Europe and China”, explains researcher Antonio Figueras. “Currently, its cultivation is well established, with the complete cycle being carried out mainly in land-based facilities. However, there are still limitations to its cultivation, including mortality episodes due to diseases caused by various pathogens, including the viral hemorrhagic septicemia virus (VHSV)”, he adds. This is because “knowledge of the species’ immune system is still scarce and little is known about pathogen-host interactions, however, to improve the species’ resistance to diseases it is essential to understand how its defense mechanisms work”, adds Beatriz Novoa.
In this context, the objective of Patricia Pereiro in her thesis was to delve deeper into the turbot response to VHSV and increase the information available in scientific databases on turbot transcript sequences related to the immune response to this virus. “A microarray was designed through which a broad transcriptomic analysis of the response in the species to a VHSV infection was carried out”, explains Pereiro, who adds that “two type I interferons were also characterized and studied for the first time, main antiviral molecules in vertebrates because they induce the expression of numerous genes capable of blocking the proliferation of viruses; both showed different properties and neither presented a protective effect against bacterial infections”.
Another of the main results of this thesis is the design and evaluation of a DNA vaccine against infection, which encodes the VHSV G glycoprotein and has been demonstrated, through laboratory tests, to induce good levels of protection in the species against the virus. Furthermore, the researcher points out that “one month after vaccination, specific antibodies against the G glycoprotein with neutralizing capacity were detected in the serum of vaccinated turbots and it was observed that, after infection, the transcriptomic profile between vaccinated and unvaccinated fish was totally different: the unvaccinated ones showed an extensive and uncontrolled immune response and the vaccinated ones a moderate and controlled response”, highlights Patricia Pereiro. The thesis also allows the identification of new genes in turbot related to the immune response and for having assumed the first transcriptomic analysis in turbot using massive sequencing.
Patricia Pereiro has a degree in Biology from the USC and later completed the interuniversity master’s degree in Aquaculture before enrolling in the doctoral program at Campus do Mar. Her research lines focus on the immune response in both turbot and zebrafish, a tropical species of great interest as a model for the study of fish immunology as well as in biomedicine. Currently, and after obtaining her doctorate, she continues to work in the IIM group with a contract associated with a project of the National R&D&I Plan of the Ministry of Economy and Competitiveness.
Patricia Pereira, third from the left, accompanied by her directors and members of the jury
Source: Duvi
