title: CsPTX1, a pentraxin of Cynoglossus semilaevis, is an innate immunity factor with antibacterial effects.
abstract: Pentraxin 1 (PTX1) is a member of the pentraxin protein family, which plays important roles in the innate immunity of vertebrates. In fish, the biological function of PTX1 is essentially unknown. In this study, we examined the expression and function of a PTX homologue (CsPTX1) from the tongue sole, Cynoglossus semilaevis. CsPTX1 contains 223 amino acids and shares 49.3%-38.8% overall sequence identity with other known fish pentraxins. CsPTX1 is expressed in multiple tissues and is upregulated by bacterial and viral infection. CsPTX1 contains a pentraxin domain, which is known to bind extracellular antigens, and recombinant CsPTX1 (rCsPTX1) bound a wide range of Gram-positive and Gram-negative bacteria. rCsPTX1 also agglutinated all the bacteria tested in a Ca(2+)-dependent manner and the agglutinating capacity of rCsPTX1 was abolished in the absence of calcium. As well as its ability to agglutinate bacterial cells, rCsPTX1 displayed apparent bacteriostatic activity against Pseudomonas fluorescens in vitro by influencing the permeability of the microbial envelope. When introduced in vivo, rCsPTX1 enhanced the host's resistance to bacterial infection. These results indicate that CsPTX1 is a classic pattern recognition molecule that defends C. semilaevis against bacterial infection.
authors.affiliation: 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.
authors.forename: Ting
authors.initials: T
authors.lastname: Wang
authors.affiliation: 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: zhangjian@qdio.ac.cn.
authors.forename: Jian
authors.initials: J
authors.lastname: Zhang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002097:C-Reactive Protein / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D004266:DNA Virus Infections / Q000235:genetics / Q000276:immunology / Q000662:veterinary / Q000821:virology; D005393:Fish Diseases / Q000235:genetics* / Q000276:immunology / Q000382:microbiology / Q000821:virology; D029941:Fish Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D005412:Flatfishes; D006090:Gram-Negative Bacteria / Q000502:physiology; D016905:Gram-Negative Bacterial Infections / Q000235:genetics / Q000276:immunology / Q000382:microbiology / Q000662:veterinary; D006094:Gram-Positive Bacteria / Q000502:physiology; D016908:Gram-Positive Bacterial Infections / Q000235:genetics / Q000276:immunology / Q000382:microbiology / Q000662:veterinary; D007113:Immunity, Innate; D007497:Iridoviridae / Q000502:physiology; D016415:Sequence Alignment / Q000662:veterinary; D059467:Transcriptome
chemical_list: D029941:Fish Proteins; D002097:C-Reactive Protein
keywords: Antibacterial effect; Bacterial agglutination; Cynoglossus semilaevis; Innate immunity; Pentraxin