Identification and molecular profiling of DC-SIGN-like from big belly seahorse (Hippocampus abdominalis) inferring its potential relevancy in host immunity

Dev Comp Immunol. 2017 Dec:77:270-279. doi: 10.1016/j.dci.2017.08.017. Epub 2017 Sep 1.

Abstract

Dendritic-cell-specific ICAM-3-grabbing non-integrin (DC-SIGN) is a C-type lectin that functions as a pattern recognition receptor by recognizing pathogen-associated molecular patterns (PAMPs). It is also involved in various events of the dendritic cell (DC) life cycle, such as DC migration, antigen capture and presentation, and T cell priming. In this study, a DC-SIGN-like gene from the big belly seahorse Hippocampus abdominalis (designated as ShDCS-like) was identified and molecularly characterized. The putative, complete ORF was found to be 1368 bp in length, encoding a protein of 462 amino acids with a molecular mass of 52.6 kDa and a theoretical isoelectric point of 8.26. The deduced amino acid sequence contains a single carbohydrate recognition domain (CRD), in which six conserved cysteine residues and two Ca2+-binding site motifs (QPN, WND) were identified. Based on pairwise sequence analysis, ShDCS-like exhibits the highest amino acid identity (94.6%) and similarity (97.4%) with DC-SIGN-like counterpart from tiger tail seahorse Hippocampus comes. Quantitative real-time PCR revealed that ShDCS-like mRNA is transcribed universally in all tissues examined, but with abundance in kidney and gill tissues. The basal mRNA expression of ShDCS-like was modulated in blood cell, kidney, gill and liver tissues in response to the stimulation of healthy fish with lipopolysaccharides (LPS), Edwardsiella tarda, or Streptococcus iniae. Moreover, recombinant ShDCS-like-CRD domain exhibited detectable agglutination activity against different bacteria. Collectively, these results suggest that ShDCS-like may potentially involve in immune function in big belly seahorses.

Keywords: Bacterial agglutination activity; Big belly seahorse; DC-SIGN; Immune stimulation; Transcription analysis.

MeSH terms

  • Animals
  • Cell Adhesion Molecules / genetics*
  • Cell Adhesion Molecules / metabolism
  • Cloning, Molecular
  • Dendritic Cells / immunology*
  • Edwardsiella tarda / immunology*
  • Enterobacteriaceae Infections / immunology*
  • Fish Diseases / immunology*
  • Fish Proteins / genetics*
  • Fish Proteins / metabolism
  • Immunity, Innate
  • Kidney / physiology*
  • Lectins, C-Type / genetics*
  • Lectins, C-Type / metabolism
  • Lipopolysaccharides / immunology
  • Phylogeny
  • Receptors, Cell Surface / genetics*
  • Receptors, Cell Surface / metabolism
  • Sequence Alignment
  • Smegmamorpha / genetics
  • Smegmamorpha / immunology*
  • Streptococcal Infections / immunology*
  • Streptococcus iniae / immunology*
  • Transcriptome

Substances

  • Cell Adhesion Molecules
  • DC-specific ICAM-3 grabbing nonintegrin
  • Fish Proteins
  • Lectins, C-Type
  • Lipopolysaccharides
  • Receptors, Cell Surface