title: Pre-exposure to yeast protects larvae of Galleria mellonella from a subsequent lethal infection by Candida albicans and is mediated by the increased expression of antimicrobial peptides.
abstract: Pre-exposure of the larvae of Galleria mellonella to Candida albicans or Saccharomyces cerevisiae protects against a subsequent infection with 10(6) C. albicans cells. This protection can also be induced by exposing larvae to glucan or laminarin prior to the administration of the potentially lethal inoculum. Analysis of the genes coding for galiomicin, a defensin in G. mellonella, a cysteine-rich antifungal peptide gallerimycin, an iron-binding protein transferrin and an inducible metalloproteinase inhibitor (IMPI) from G. mellonella demonstrated increased expression, which is at its highest after 24 h of the initial inoculum. Examination of the expression of proteins in the insect haemolymph using 2D electrophoresis and MALDI TOF analysis revealed an increased expression of a number of proteins associated with the insect immune response to infection 24 h after the initial exposure. This study demonstrates that the larvae of G. mellonella can withstand a lethal inoculum of C. albicans if pre-exposed to a non-lethal dose of yeast or polysaccharide 24 h previously which is mediated by increased expression of a number of antimicrobial peptides and the appearance of a number of peptides in the challenged larvae.
authors.affiliation: Department of Biology, Medical Mycology Unit, NICB, National University of Ireland Maynooth, Co. Kildare, Ireland.
authors.forename: David
authors.initials: D
authors.lastname: Bergin
authors.forename: Lisa
authors.initials: L
authors.lastname: Murphy
authors.forename: Joanne
authors.initials: J
authors.lastname: Keenan
authors.forename: Martin
authors.initials: M
authors.lastname: Clynes
authors.forename: Kevin
authors.initials: K
authors.lastname: Kavanagh
mesh_terms: D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000032:analysis / Q000235:genetics*; D002176:Candida albicans / Q000276:immunology*; D023082:Defensins / Q000032:analysis / Q000235:genetics; D015180:Electrophoresis, Gel, Two-Dimensional; D005786:Gene Expression Regulation; D017344:Genes, Insect; D005936:Glucans / Q000276:immunology; D006458:Hemolymph / Q000737:chemistry; D019476:Insect Proteins / Q000032:analysis / Q000235:genetics*; D007814:Larva / Q000276:immunology / Q000382:microbiology; D009036:Moths / Q000235:genetics / Q000276:immunology* / Q000382:microbiology*; D011134:Polysaccharides / Q000276:immunology; D020543:Proteome / Q000032:analysis; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012441:Saccharomyces cerevisiae / Q000276:immunology; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D016019:Survival Analysis; D014168:Transferrin / Q000235:genetics
chemical_list: D023181:Antimicrobial Cationic Peptides; D023082:Defensins; D005936:Glucans; D019476:Insect Proteins; D011134:Polysaccharides; D020543:Proteome; D012333:RNA, Messenger; D014168:Transferrin; C512107:gallerimycin; C008247:laminaran