Articles

Immune Characterization of C-Type Lectin-Like Protein in Rainbow Trout

Authors:

Jiaqing Wang, Irina Yu. Potoroko, Lina A. Tsirulnichenko

Abstract:

C-type lectins play crucial roles in innate immunity and pathogen recognition. In this study, a C-type lectin-like protein (Om-CTLP) gene was cloned from rainbow trout, Oncorhynchus mykiss by rapid amplification of cDNA ends (RACE) PCR. The full-length cDNA of Om-CTLP was composed of 1,153 bp with a 723 bp open reading frame (ORF) that encodes a 240-residue protein with an estimated molecular mass of 27 kD and a predicted isoelectric point of 5.48. The deduced amino acid sequence of Om-CTLP possessed all conserved features crucial for the fundamental structure, such as the four cysteine residues (Cys128-Cys230, Cys207- Cys222) formed the carbohydrate recognition domain (CRD) internal disulfide bridges and the potential Ca2+/carbohydrate-binding sites. Om-CTLP contains a transmembrane domain and a single CRD. Om-CTLP showed high similarity of 44%-84% with C-type lectins from other fish species. Quantitative RT–PCR (qRT-PCR) analysis showed Om-CTLP mRNA was constitutive expression in gill, heart, liver, kidney, intestine, spleen and muscle tissues in healthy fish and up-regulated under infection by bacteria or viruses. After being infected by Aeromonas hydrophila or viral haemorrhagic septicemia virus (VHSV), the expression of Om-CTLP were up-regulated from 12 h post-injection and lasted until the fish became moribund (P<0.05). The recombinant Om-CTLP CRD can agglutinate both Gram-positive (Staphylococcus aureus) and Gram-negative bacteria (A. hydrophila) in a Ca2+-dependent manner. Further analysis showed that the recombinant Om-CTLP can directly bind to all tested microorganisms (S. aureus, Bacillus thuringiensis, Bacillus subtilis, Escherichia coli, Vibrio natriegens, Vibrio parahaemolyticus, and A. hydrophila). These results suggest that Om-CTLP may have important roles in anti-bacterial and anti-viral immunity of rainbow trout.

Keywords:

C-type lectin; Om-CTLP; qRT-PCR; mRNA expression; Innate immunity

For citation: Jiaqing Wang, Irina Yu. Potoroko, Lina A. Tsirulnichenko. Immune Characterization of C-Type Lectin-Like Protein in Rainbow Trout. Индустрия питания|Food Industry. 2018. Vol. 3, No. 4. С. 88–96. DOI 10.29141/2500-1922-2018-3-4-11

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