title: Characterization and expression analysis of a peptidoglycan recognition protein gene, SmPGRP2 in mucosal tissues of turbot (Scophthalmus maximus L.) following bacterial challenge.
abstract: Peptidoglycan recognition receptor proteins (PGRPs), a group of pattern recognition receptors (PRRs), can recognize peptidoglycan (PGN) of the bacteria cell wall and play an important role in host immune defense against pathogen infection. They are highly structurally conserved through evolution, but with different function in innate immunity between invertebrates and vertebrates. In teleost fish, several PGRPs have been characterized recently. They have both amidase activity and bactericidal activity and are involved in indirectly killing bacteria and regulating multiple signaling pathways. However, the knowledge of PGRPs in mucosal immunity of teleost fish is still limited. In this study, we identified a PGRPs gene (SmPGRP2) of turbot and investigated its expression patterns in mucosal tissues after challenge with Gram-positive bacteria Streptococcus iniae and Gram-negative bacteria Vibrio anguillarum. Phylogenetic analysis showed the strongest relationship of turbot PGRP to halibut, which was consistent with their phylogenetic relationships. In addition, SmPGRP2 was ubiquitously expressed in turbot tissues, and constitutive expression levels were higher in classical immune tissues (including liver, spleen, and head-kidney) than mucosal tissues (intestine, gill and skin). After bacterial challenge, the expression of SmPGRP2 was induced and showed a general trend of up-regulation in mucosal tissues, except in intestine following V. anguillarum infection. These different expression patterns varied depending on both pathogen and tissue type, suggesting its distinct roles in the host immune response to bacterial pathogen.
authors.affiliation: Marine Science and Engineering College, Qingdao Agricultural University, Qingdao, 266109, China.
authors.forename: Linan
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Marine Science and Engineering College, Qingdao Agricultural University, Qingdao, 266109, China.
authors.forename: Chengbin
authors.initials: C
authors.lastname: Gao
authors.affiliation: Marine Science and Engineering College, Qingdao Agricultural University, Qingdao, 266109, China.
authors.forename: Fengqiao
authors.initials: F
authors.lastname: Liu
authors.affiliation: Marine Science and Engineering College, Qingdao Agricultural University, Qingdao, 266109, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Song
authors.affiliation: Ministry of Agriculture Key Laboratory of Freshwater Aquatic Biotechnology and Breeding, Heilongjiang Fisheries Research Institute, Chinese Academy of Fishery Sciences, Harbin, 150070, China; National and Local Joint Engineering Laboratory for Freshwater Fish Breeding, Heilongjiang Fisheries Research Institute, Chinese Academy of Fishery Sciences, Harbin, 150070, China.
authors.forename: Baofeng
authors.initials: B
authors.lastname: Su
authors.affiliation: Marine Science and Engineering College, Qingdao Agricultural University, Qingdao, 266109, China. Electronic address: leoochao@163.com.
authors.forename: Chao
authors.initials: C
authors.lastname: Li
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D005393:Fish Diseases / Q000235:genetics* / Q000276:immunology / Q000382:microbiology; D029941:Fish Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D005412:Flatfishes; D005786:Gene Expression Regulation; D007113:Immunity, Innate; D009092:Mucous Membrane / Q000276:immunology; D010802:Phylogeny; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011897:Random Allocation; D016415:Sequence Alignment / Q000662:veterinary; D013290:Streptococcal Infections / Q000235:genetics / Q000276:immunology / Q000382:microbiology / Q000662:veterinary*; D000070058:Streptococcus iniae / Q000502:physiology; D014733:Vibrio / Q000502:physiology; D014735:Vibrio Infections / Q000235:genetics / Q000276:immunology / Q000382:microbiology / Q000662:veterinary*
chemical_list: D002352:Carrier Proteins; D029941:Fish Proteins; D012333:RNA, Messenger; C118897:peptidoglycan recognition protein
keywords: Mucosal immunity; Peptidoglycan recognition protein; Streptococcus iniae; Turbot; Vibrio anguillarum