Journal
FISH & SHELLFISH IMMUNOLOGY
Volume 76, Issue -, Pages 58-67Publisher
ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD
DOI: 10.1016/j.fsi.2018.02.038
Keywords
Ayu; Bacterial agglutination; Complement-mediated opsonophagocytosis; Monocyte/macrophage; Sequence analysis; Short-chain pentraxins
Funding
- Program for the Natural Science Foundation of China [31402323, 31772876, 31372555]
- Natural Science Foundation of Zhejiang Province [LY14C190007, LZ18C190001]
- Scientific Innovation Team Project of Ningbo [2015C110018]
- Natural Science Foundation of Ningbo City of China [2017A610284]
- Ningbo Science and Technology Fumin Engineering Project [2017C10037]
- open Fund of Zhejiang Provincial Top Key Discipline of Aquaculture in Ningbo University [xkzsc1417]
- K.C. Wong Magna Fund in Ningbo University
Ask authors/readers for more resources
The short-chain pentraxins (PTXs), including C-reactive protein (CRP) and serum amyloid P (SAP), are soluble pattern recognition molecules (PRMs) that exhibit calcium-dependent binding to bacterial surface molecules. They opsonize pathogens or other particles by phagocytic clearance. However, the detailed functions of short chain PTXs in teleosts remained unclear. In this study, we identified a short-chain PTX gene from ayu, Plecoglossus altivelis, and tentatively named as PaCRP/SAP. Sequence analysis revealed that PaCRP/SAP has typical characteristics of fish CRP/SAP and is mostly closely related to rainbow smelt (Osmerus mordax) SAP. PaCRP/SAP transcripts were detected in all tested tissues, with the highest level in the liver, and its expression significantly upregulated following Vibrio anguillarum infection. The active recombinant mature PaCRP/SAP (rPaCRP/SAPm) agglutinated Gram-negative bacteria (Escherichia coli, V. anguillarum, Aeromonas hydrophila, and Vibrio parahaemolyticus) and Gram-positive bacteria (Staphylococcus aureus and Listeria monocytogenes) in a calcium-dependent manner in vitro, and it correspondingly bound peptidoglycan and lipopolysaccharide in a dose-dependent manner. The binding of rPaCRP/SAPm to E. coli and S. aureus resulted in a clear inhibition of the deposition of ayu complement 3 (PaC3) on the bacteria. Furthermore, rPaCRP/SAPm decreased phagocytosis of rPaCRP/SAPm-bound E. coli and S. aureus cells by ayu monocytes/macrophages (MO/M Phi) in a complement dependent way. However, rPaCRP/SAPm alone had no significant influence on phagocytosis. These results provided the first evidence that PaCRP/SAP might function in ayu immune responses via agglutinating bacteria and inhibiting complement-mediated opsonophagocytosis by MO/M Phi.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available