Sea lice vaccine development based on an immunogenic peptide derived from the ribosomal protein P0

Abstract

Sea lice (Copepoda, Caligidae) are the most widely distributed marine pathogens in the salmon industry. Vaccination is considered an efficient, environmentally safe and economically sustainable alternative for control of ectoparasite infestations. Although emerging sea lice proteins have been identified recently, and have been proposed as potential targets for generating protective molecules, only a limited number of them have been evaluated in vaccine trials with unsuccessful results. On the other hand, more than 80 proteins are found in eukaryotic ribosomes. The protein P0 is essential for the assembly of the 60S ribosomal subunit and essential for cell viability. A vaccinationchallenge trial with an immunogenic peptide of Rhipicephalus sanguineus protein P0 reduced survival of ticks with an overall efficacy of 90%, suggesting that it might be a promising antigen candidate for the control of ectoparasite. We have identified an immunogenic region of the ribosomal protein P0 from Caligus rogercresseyi and Lepeophtheirus salmonis that is not very conserved compared to host P0. We developed several vaccine candidates based on this peptide and produced in E. coli. These antigens were able to elicit a high specific antibody response after intraperitoneal (ip) immunization using tilapia as teleost fish model. It has been shown that ip immunization with some antigens cannot significantly reduce larval lice numbers despite enhanced specific antibody titers were raised. In this context, we have been developed for first time several tools to monitor tilapia immune response (IgT, IFN-γ, IL-4, CD154) to vaccination in order to perform a more complete evaluation of the impact of the vaccinate candidates on the fish immune system. These findings will be finally validated in an immunization-challenge trial in Salmo salar. The overall results are relevant in the development of an effective vaccine against sea lice.

Comparative Tandem Mass Tag-Based Quantitative Proteomic Analysis of Tachaea chinensis Isopod During Parasitism

“…Anticlotting-related proteins are considered potential targets for the development of new drugs and vaccines to control and prevent ectoparasites such as ticks (Oleaga et al, 2017), mosquitos (Popova-Butler and Donald, 2009; Tetreau et al, 2012), Schistosoma (Delcroix et al, 2006), and sea louse (Carpio et al, 2011, 2016). However, the hosts of these parasites are vertebrates, in which the composition of the coagulation system differs from that of invertebrates.…”

Metazoan Parasite Vaccines: Present Status and Future Prospects

“…In these cases, to further antigen discovery, a related parasitic species can be used that have a permissible animal model for vaccine trial evaluations. In this manner homologous target proteins can be identified that may confer cross-species protection such as subolesin/akarin and P0 antigens (Moreno-Cid et al, 2013 ; de La Fuente and Contreras, 2015 ; Mallon et al, 2015 ; Carpio, 2016 ; Villar et al, 2017 ). Additional in vitro feeding systems for ectoparasites such as ticks, lice, mites and mosquitoes have become valuable tools for parasite study and development of antiparasitics by mitigating the requirement for host animal challenges and affording a platform for high-throughput studies (i.e., infection studies, gene knock-down and chemical assays) (Kessler et al, 2014 ; Bartley et al, 2015 ; Sangaré et al, 2016 ; Agramonte et al, 2017 ; Kim et al, 2017 ; Krull et al, 2017 ; Trentelman et al, 2017 ).…”