CsSAP, a teleost serum amyloid P component, interacts with bacteria, promotes phagocytosis, and enhances host resistance against bacterial and viral infection

Ting Wang; Li Sun

doi:10.1016/j.dci.2015.10.002

CsSAP, a teleost serum amyloid P component, interacts with bacteria, promotes phagocytosis, and enhances host resistance against bacterial and viral infection

Dev Comp Immunol. 2016 Feb:55:12-20. doi: 10.1016/j.dci.2015.10.002. Epub 2015 Oct 8.

Authors

Ting Wang¹, Li Sun²

Affiliations

¹ Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China; University of Chinese Academy of Sciences, Beijing, China.
² Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China. Electronic address: lsun@qdio.ac.cn.

PMID: 26454233
DOI: 10.1016/j.dci.2015.10.002

Abstract

Serum amyloid P component (SAP) is a member of the pentraxins family that plays important roles in innate immunity in vertebrates. In fish, the biological function of SAP is essentially unknown. In this study, we examined the expression and function of a SAP homologue (CsSAP) from tongue sole Cynoglossus semilaevis. CsSAP shares 46%-58% overall sequence identities with known fish SAP and was upregulated in expression by bacterial and viral infection. Recombinant CsSAP (rCsSAP) exhibited differential binding capacities to a wide range of Gram-positive and Gram-negative bacteria and promoted uptake of the bound bacteria by host phagocytes. When introduced in vivo, rCsSAP enhanced host resistance not only to bacterial infection but also to viral infection. Consistently, antibody blockage of CsSAP significantly weakened the ability of tongue sole to clear invading bacteria. These results provide the first evidence that fish SAP contributes significantly to both antibacterial and antiviral immunities.

Keywords: Antibacterial; Antiviral; Cynoglossus semilaevis; Innate immunity; Serum amyloid P component.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Amino Acid Sequence
Animals
Antibodies, Blocking / administration & dosage
Bacterial Infections / immunology*
Bacterial Load / drug effects
Fish Diseases / immunology*
Fish Proteins / genetics
Fish Proteins / metabolism*
Flatfishes / immunology*
Gene Expression Regulation
Host-Pathogen Interactions / genetics
Immunity, Innate / genetics
Molecular Sequence Data
Phagocytosis / genetics
Sequence Homology, Amino Acid
Serum Amyloid P-Component / genetics
Serum Amyloid P-Component / metabolism*
Virus Diseases / immunology*

Substances

Antibodies, Blocking
Fish Proteins
Serum Amyloid P-Component