title: Maggot excretions affect the human complement system.
abstract: The complement system plays an important role in the activation of the inflammatory response to injury, although inappropriate complement activation (CA) can lead to severe tissue damage. Maggot therapy is successfully used to treat infected wounds. In this study, we hypothesized that maggot excretions/secretions influence CA in order to modulate the host's inflammatory response. Therefore, the effect of maggot excretions on CA was investigated in preoperatively and postoperatively obtained sera from patients. Our results show that maggot excretions reduce CA in healthy and postoperatively immune-activated human sera up to 99.9%, via all pathways. Maggot excretions do not specifically initiate or inhibit CA, but break down complement proteins C3 and C4 in a cation-independent manner and this effect proves to be temperature tolerant. This study indicates a CA-reducing substrate that is already successfully used in clinical practice and may explain part of the improved wound healing caused by maggot therapy. Furthermore, the complement activation-reducing substance present in maggot excretions could provide a novel treatment modality for several diseases, resulting from an (over)active complement system.
authors.affiliation: Department of Surgery, Bronovo Hospital, The Hague, The Netherlands. gwendolyn_cazander@hotmail.com
authors.forename: Gwendolyn
authors.initials: G
authors.lastname: Cazander
authors.forename: Marco W J
authors.initials: MW
authors.lastname: Schreurs
authors.forename: Lennaert
authors.initials: L
authors.lastname: Renwarin
authors.forename: Corry
authors.initials: C
authors.lastname: Dorresteijn
authors.forename: Dörte
authors.initials: D
authors.lastname: Hamann
authors.forename: Gerrolt N
authors.initials: GN
authors.lastname: Jukema
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D002908:Chronic Disease; D003176:Complement C3 / Q000276:immunology*; D003179:Complement C3b / Q000276:immunology; D015933:Complement C3d / Q000276:immunology; D003181:Complement C4 / Q000276:immunology*; D003646:Debridement / Q000379:methods*; D005260:Female; D006801:Humans; D007113:Immunity, Innate; D007814:Larva; D008213:Lymphocyte Activation; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000276:immunology; D010865:Pilot Projects; D015398:Signal Transduction; D014945:Wound Healing / Q000276:immunology; D014946:Wound Infection / Q000276:immunology / Q000473:pathology / Q000628:therapy*; D014947:Wounds and Injuries / Q000276:immunology / Q000473:pathology / Q000628:therapy*
chemical_list: D000900:Anti-Bacterial Agents; C082625:C3 beta c; D003176:Complement C3; D003181:Complement C4; D010446:Peptide Fragments; D003179:Complement C3b; D015933:Complement C3d