Identification, functional characterization and the potential role of variable lymphocyte receptor EsVLRA from Eriocheir sinensis in response to secondary challenge after Vibrio parahaemolyticus vaccine. Issue 98 (March 2020)

• Record Type: Journal Article
• Authors: Liu, Hourong; Song, Chengwen; Ning, Junhao; Liu, Yuan; Cui, Zhaoxia
• Is Part Of: Fish & shellfish immunology. Issue 98(2020)
• Page Start: 201
• Page End: 209
• Publication Date: 2020-03
• Subjects: Eriocheir sinensis -- Variable lymphocyte receptors -- Bacteria-binding activity -- Immune priming; Fishes -- Immunology -- Periodicals; Shellfish -- Immunology -- Periodicals; Poissons -- Immunologie -- Périodiques; Crustacés -- Immunologie -- Périodiques; 571.9617
• DOI: 10.1016/j.fsi.2020.01.011
• Languages: English
• ISSNs: 1050-4648

Abstract

Abstract: Variable lymphocyte receptors (VLRs) play an important role via their antigen-special reorganization in jawless vertebrates (agnathans) adaptive immune response. In the present study, the open reading frame (ORF) of Eriocheir sinensis VLRA (designated as EsVLRA) was identified. EsVLRA comprised a 799-amino-acid polypeptide with one LRR_NT domain, thirteen LRR domains and one LRR_CT domain, which showed a high domain consistency of the VLR genes in lamprey ( Petromyzon marinus ). The transcript of EsVLRA was detected in all examined tissues with the highest level detected in hepatopancreas. Notably, the expression of EsVLRA in hepatopancreas, gonads, gill and intestine of male crabs was significantly higher than that in females. The recombinant EsVLRA exhibited strong bacteria-binding activity rather than antibacterial activity, suggesting its crucial role in immune recognition. Furthermore, 6 h earlier response and a significantly higher peak of EsVLRA mRNA expression was observed after challenge with live Vibrio parahaemolyticus (240.6-fold, P < 0.01, crabs receive secondary challenge after V. parahaemolyticus vaccine to the carbs only receive twice PBS injection, N = 6), compared with those only received first injection with formalin-inactivated V. parahaemolyticus (39.7-fold, P < 0.01, challenge 6 h to vaccination 12 h). The findings of this study together demonstrated that EsVLRA plays an important role in the immune system of E. sinensis, serving as a pattern recognition receptor and involving in the immune priming. Highlights: EsVLRA contained the conserved LRR_CT domain with a protruding loop at LRR_CT region. The highest transcript level of EsVLRA was detected in hepatopancreas. The recombinant EsVLRA exhibited strong microbial-binding activity. EsVLRA might be involved in immune priming via its immune priming.