Systemic and Mucosal B and T Cell Responses Upon Mucosal Vaccination of Teleost Fish

Abstract

The development of mucosal vaccines against pathogens is currently a highly explored area of research in both humans and animals. This is due to the fact that mucosal vaccines have the potential to best elicit protective responses at these mucosal surfaces, which represent the frontline of host defense, thus blocking the pathogen at its initial replication sites. However, in order to provide an efficient long-lasting protection, these mucosal vaccines have to be capable of eliciting an adequate systemic immune response in addition to local responses. In aquaculture, the need for mucosal vaccines has further practical implications, as these vaccines would avoid the individual manipulation of fish out of the water, being beneficial from both an economic and animal welfare point of view. However, how B and T cells are organized in teleost fish within these mucosal sites and how they respond to mucosally delivered antigens varies greatly when compared to mammals. For this reason, it is important to establish which mucosally delivered antigens have the capacity to induce strong and long-lasting B and T cell responses. Hence, in this review, we have summarized what is currently known regarding the adaptive immune mechanisms that are induced both locally and systemically in fish after mucosal immunization through different routes of administration including oral and nasal vaccination, anal intubation and immersion vaccination. Finally, based on the data presented, we discuss how mucosal vaccination strategies could be improved to reach significant protection levels in these species.

A review on the recent advances and application of vaccines against fish pathogens in aquaculture

“…Mucosal vaccines are now gaining wide attention in aquaculture due to the longer period of immunity in the vaccinated fishes (Dadar et al 2016 ). The development of mucosal vaccines against pathogenic infections in aquaculture is currently the focus of research since they have the potential to elicit the protective responses at the mucosal surfaces by blocking the pathogens at the initial site of replication (Muñoz-Atienza et al 2021 ). A study was performed on the mucosal and systemic responses of the B and T cells upon immunizing with mucosal vaccines against pathogens in teleost fishes via different routes of administration which included oral, immersion, and nasal vaccination (Muñoz-Atienza et al 2021 ).…”

Bacillus subtilis Expressing the Infectious Pancreatic Necrosis Virus VP2 Protein Retains Its Immunostimulatory Properties and Induces a Specific Antibody Response

“…In aquaculture, mucosal immunization has several advantages over systemic vaccination. First of all, as the higher capacity of mucosal immunization to trigger mucosal immunity than that of systemic immunization has been broadly demonstrated ( 30 – 33 ), an effective response established at these mucosal sites through this type of vaccination would block pathogens at these entry sites before they colonize the host ( 20 , 30 , 34 , 35 ). On the other hand, oral delivery or immersion of vaccines in fish farms imply less economic costs and reduced fish stress while it facilitates vaccination at early developmental stages when fish are more susceptible to infections ( 32 , 36 , 37 ).…”

Revealing New Landscape of Turbot (Scophthalmus maximus) Spleen Infected with Aeromonas salmonicida through Immune Related circRNA-miRNA-mRNA Axis

“…The spleen is the primary immune tissue of teleost except kidney, thymus, and mucosaassociated lymphoid tissues. The spleen not only contains immune T cells and immune B cells that can destroy or neutralize antigens to prevent further manifestations during the disease process, but also plays an important role in antigen presentation and adaptive immune response [46,47]. Therefore, expression profiling of the spleen of S. maximus infected with A. salmonicida will be helpful to understand the mechanism of disease resistance and disease defense of S. maximus.…”