title: Identification of five anti-lipopolysaccharide factors in oriental river prawn, Macrobrachium nipponense.
abstract: Anti-lipopolysaccharide factors (ALFs) are a group of antimicrobial peptides (AMPs) with broad-spectrum antimicrobial activities and antiviral activities mainly found in crustaceans and horseshoe crabs. In the present study, we identified 5 ALF expression sequence tags (ESTs) through analysis of the established M. nipponense transcriptome, and cloned their full-length cDNA sequences using rapid amplification of cDNA ends (RACE) method. The 5 ALFs were designated as MnALF1-5, and all of them showed high similarity with their Macrobrachium rosenbergii homologs in the phylogenetic analyses, especially in LPS binding domains. In healthy adult prawns, we found the highest expression of MnALF2 and MnALF4 in haemocytes, and the highest expression of MnALF4 and MnALF3 in intestine. Some isoforms of MnALF were down-regulated but the majority was up-regulated in different prawn tissues upon Aeromonas hydrophila challenge. To conform the expected antimicrobial activities harbored in MnALFs' LPS binding domains, we used a synthesized peptide cMnALF24 that corresponds to the LPS binding domain of MnALF2 as a representative molecule for the antibacterial activity test, and found that cMnALF24 possessed strong and broad-spectrum antibacterial activity against Gram positive and Gram negative bacteria, but no inhibition activity against fungi; Meanwhile, in the hemolytic test, cMnALF24 showed weak hemolysis activities (around 10%) to the rabbit red blood cells at concentrations of 0.67-33.50 μM. This study provides insights into understanding the antibacterial function of ALFs in the innate immunity of freshwater prawn, and reports a peptide that can be a potential drug candidate with good efficacy against bacterial infection and low toxicity to host cells.
authors.affiliation: College of Life Sciences, Hebei University, Baoding, Hebei, China.
authors.forename: Yili
authors.initials: Y
authors.lastname: Wang
authors.affiliation: College of Life Sciences, Hebei University, Baoding, Hebei, China; The Key Laboratory of Zoological Systematics and Application, College of Life Sciences, Hebei University, Baoding, Hebei, 071002, China.
authors.forename: Ting
authors.initials: T
authors.lastname: Tang
authors.affiliation: College of Life Sciences, Hebei University, Baoding, Hebei, China.
authors.forename: Jihai
authors.initials: J
authors.lastname: Gu
authors.affiliation: College of Life Sciences, Hebei University, Baoding, Hebei, China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Li
authors.affiliation: College of Life Sciences, Hebei University, Baoding, Hebei, China.
authors.forename: Xue
authors.initials: X
authors.lastname: Yang
authors.affiliation: Department of Pathology, Yale University, New Haven, CT, USA.
authors.forename: Xiaobin
authors.initials: X
authors.lastname: Gao
authors.affiliation: College of Life Sciences, Hebei University, Baoding, Hebei, China; The Key Laboratory of Zoological Systematics and Application, College of Life Sciences, Hebei University, Baoding, Hebei, 071002, China. Electronic address: liufengsong@hbu.edu.cn.
authors.forename: Fengsong
authors.initials: F
authors.lastname: Liu
authors.affiliation: Department of Pathology, Yale University, New Haven, CT, USA. Electronic address: jianhui.wang@yale.edu.
authors.forename: Jianhui
authors.initials: J
authors.lastname: Wang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000890:Anti-Infective Agents / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides / Q000235:genetics* / Q000378:metabolism; D060829:Arthropod Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D002681:China; D005658:Fungi / Q000502:physiology; D006090:Gram-Negative Bacteria / Q000502:physiology; D006094:Gram-Positive Bacteria / Q000502:physiology; D007113:Immunity, Innate; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008969:Molecular Sequence Data; D033541:Palaemonidae / Q000235:genetics* / Q000378:metabolism / Q000382:microbiology; D010802:Phylogeny; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment
chemical_list: D000890:Anti-Infective Agents; D023181:Antimicrobial Cationic Peptides; D060829:Arthropod Proteins; D008070:Lipopolysaccharides; D020033:Protein Isoforms
keywords: Anti-lipopolysaccharide factors; Antimicrobial activity; Innate immunity; Macrobrachium nipponense