In-Depth In Silico Search for Cuttlefish ( Sepia officinalis) Antimicrobial Peptides Following Bacterial Challenge of Haemocytes

• Published in: Marine drugs Vol. 18; no. 9; p. 439
• Main Authors: Benoist, Louis, Houyvet, Baptiste, Henry, Joël, Corre, Erwan, Zanuttini, Bruno, Zatylny-Gaudin, Céline
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 24.08.2020; MDPI
• Subjects: Analysis; Animals; Annotations; Anti-Bacterial Agents - metabolism; Anti-Bacterial Agents - pharmacology; Antibacterial activity; Antibiotics; Antimicrobial agents; antimicrobial peptide; Antimicrobial peptides; Aquaculture; Bacteria; challenge; Chemical Sciences; Cytokines; Data Mining; Databases, Genetic; Decapodiformes - genetics; Decapodiformes - immunology; Decapodiformes - metabolism; Decapodiformes - microbiology; Defence mechanisms; Depth; Female; Fish Proteins - genetics; Fish Proteins - metabolism; Fish Proteins - pharmacology; Gene Expression Regulation; Gram-negative bacteria; Gram-Negative Bacteria - drug effects; haemocyte; Hemocytes; Hemocytes - immunology; Hemocytes - metabolism; Hemocytes - microbiology; Hemolysis - drug effects; Host-Pathogen Interactions; Humans; Identification; Immune response; Immune system; Immunity; Immunological factors; Immunology; in vitro; Innate immunity; Life Sciences; Marine molluscs; Medicinal Chemistry; Microbial Sensitivity Tests; Minimum inhibitory concentration; mollusc; Mollusks; Nervous system; NF-κB protein; Peptides; Pore Forming Cytotoxic Proteins - genetics; Pore Forming Cytotoxic Proteins - metabolism; Pore Forming Cytotoxic Proteins - pharmacology; Proteins; Sepia officinalis; Software; Transcriptome; Vibrio - immunology; Vibrio - pathogenicity; Vitamin B; Waterborne diseases; Sepia officinalis; mollusc; Vibrio splendidus; in vitro; challenge; haemocyte; antimicrobial peptide
• ISSN: 1660-3397; 1660-3397
• DOI: 10.3390/MD18090439

Cuttlefish ( ) haemocytes are potential sources of antimicrobial peptides (AMPs). To study the immune response to and identify new AMPs, an original approach was developed based on a differential transcriptomic study and an in-depth in silico analysis using multiple tools. Two de novo transcriptomes were retrieved from cuttlefish haemocytes following challenge by . or not. A first analysis of the annotated transcripts revealed the presence of Toll/NF-κB pathway members, including newly identified factors such as -TLR-h, -IKK-h and -Rel/NF-κB-h. Out of the eight Toll/NF-κB pathway members, seven were found up-regulated following . challenge. Besides, immune factors involved in the immune response were also identified and up-regulated. However, no AMP was identified based on annotation or conserved pattern searches. We therefore performed an in-depth in silico analysis of unannotated transcripts based on differential expression and sequence characteristics, using several tools available like PepTraq, a homemade software program. Finally, five AMP candidates were synthesized. Among them, NF19, AV19 and GK28 displayed antibacterial activity against Gram-negative bacteria. Each peptide had a different spectrum of activity, notably against species. GK28-the most active peptide-was not haemolytic, whereas NF19 and AV19 were haemolytic at concentrations between 50 and 100 µM, 5 to 10 times higher than their minimum inhibitory concentration.