Quadruple domain-containing galectin from marine invertebrate disk abalone (Haliotis discus discus): Molecular perspectives in early development, immune expression, and potent antiviral responses. Issue 106 (November 2020)

• Record Type: Journal Article
• Authors: Gayashani Sandamalika, W.M.; Lee, Jehee
• Is Part Of: Fish & shellfish immunology. Issue 106(2020)
• Page Start: 920
• Page End: 929
• Publication Date: 2020-11
• Subjects: Quadruple domain-containing galectin -- Disk abalone (Haliotis discus discus) -- mRNA expression pattern -- Antiviral responses -- Early developmental stages; Fishes -- Immunology -- Periodicals; Shellfish -- Immunology -- Periodicals; Poissons -- Immunologie -- Périodiques; Crustacés -- Immunologie -- Périodiques; 571.9617
• DOI: 10.1016/j.fsi.2020.09.017
• Languages: English
• ISSNs: 1050-4648

Abstract

Abstract: Galectins are well-known β-galactoside-binding proteins, which play vital roles in innate immune responses of both vertebrates and invertebrates. However, knowledge regarding invertebrate galectins is still in its infancy. With the intention of filling the knowledge gap, here we identified a quadruple domain-containing galectin from marine invertebrate disk abalone, Haliotis discus discus ( AbGalec ), and characterized it. AbGalec consisted of four distinct carbohydrate-recognition domains (CRDs) and lacked a signal peptide. Expression analysis revealed AbGalec to be ubiquitously expressed in all the examined early embryonic stages of abalone, with highest expression in the 16-cell stage, suggesting the importance of AbGalec in early developmental processes. Tissue distribution analysis revealed the highest expression of AbGalec in abalone mantle, followed by that in gills and hemocytes. Immune challenge experiments revealed significant upregulation of AbGalec at 24 h and 48 h post injection (p.i.) with bacterial and viral components. These results suggested the possible involvement of AbGalec in host defense mechanisms. Polyinosinic: polycytidylic acid (Poly I:C) and viral hemorrhagic septicemia virus (VHSV) injections were capable of inducing AbGalec transcript expression more prominently than bacterial stimulants, thus providing evidence for its role in viral infections. We determined the virus-neutralizing ability of a quadruple domain-containing galectin for the first time, by analyzing the downregulation of VHSV transcripts during the overexpression of AbGalec. Significant downregulation of VHSV transcripts was observed after 24 h and 48 h of post infection. Collectively, our findings reveal the potent antiviral responses of molluscan quadruple domain-containing galectin, AbGalec, along with its involvement in innate immunity. Highlights: We identified a quadruple domain-containing galectin from disk abalone ( AbGalec ). AbGalec was highly expressed in 16-cell stage during embryogenesis. AbGalec was highly expressed in the abalone mantle. AbGalec mRNA expression level significantly increased after immune challenge. Significant reduction of VHSV transcripts was observed with overexpressed AbGalec.