title: Humoral immune response of the small-spotted catshark, Scyliorhinus canicula.
abstract: Cartilaginous fishes are the oldest group in which an adaptive immune system based on immunoglobulin-superfamily members is found. This manuscript compares humoral immune function in small-spotted catshark (Scyliorhinus canicula) with that described for spiny dogfish (Squalus acanthias), another member of the Squalomorphi superorder, and nurse shark, the model for humoral immunity in elasmobranchs and a member of the Galeomorphi superorder. Although small-spotted catshark and nurse shark are separated by over 200 million years we found that immunoglobulin isoforms are well conserved between the two species. However, the plasma protein profile of small-spotted catshark was most similar to that of spiny dogfish, with low levels of pentameric IgM, and IgNAR present as a multimer in plasma rather than a monomer. We show that an antigen-specific monomeric IgM response, with a profile similar to that described previously for nurse sharks, can be raised in small-spotted catshark. Lacking polyclonal or monoclonal antibody reagents for detecting catshark IgNAR we investigated phage-display and recombinant Fc-fusion protein expression as alternative methods to look for an antigen-specific response for this isotype. However, we could find no evidence of an antigen-specific IgNAR in the animals tested using either of these techniques. Thus, unlike nurse sharks where antigen-specific monomeric IgM and IgNAR appear together, it seems there may be a temporal or complete 'uncoupling' of these isotypes during a humoral response in the small-spotted catshark.
authors: Global Biotherapeutics Technologies, Pfizer Inc., Foresterhill, Aberdeen AB25 2ZS, United Kingdom.
authors: Kathryn
authors: K
authors: Crouch
authors: Lauren E
authors: LE
authors: Smith
authors: Rebecca
authors: R
authors: Williams
authors: Wei
authors: W
authors: Cao
authors: Mike
authors: M
authors: Lee
authors: Allan
authors: A
authors: Jensen
authors: Helen
authors: H
authors: Dooley
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015139:Blotting, Southern; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D056724:Immunity, Humoral; D007132:Immunoglobulin Isotypes / Q000097:blood / Q000235:genetics; D007136:Immunoglobulins / Q000097:blood / Q000235:genetics*; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012606:Scotland; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D012754:Sharks / Q000235:genetics* / Q000276:immunology* / Q000378:metabolism; D013045:Species Specificity; D048251:Squalus acanthias / Q000235:genetics / Q000276:immunology / Q000378:metabolism
chemical_list: D018076:DNA, Complementary; D007132:Immunoglobulin Isotypes; D007136:Immunoglobulins; D012333:RNA, Messenger