title: Susceptibility of Vibrio aestuarianus 01/032 to the antibacterial activity of Mytilus haemolymph: identification of a serum opsonin involved in mannose-sensitive interactions.
abstract: The interactions of Vibrio aestuarianus 01/032 with haemolymph of the bivalves Mytilus galloprovincialis and Crassostrea gigas were investigated to understand if haemolymph components (haemocytes and soluble factors) could be involved in the higher resistance to microbial infection shown by mussels in comparison with oysters. Although 01/032 bacteria adhered to haemocytes of both bivalves, they were sensitive to the bactericidal activity of whole haemolymph from mussel, but not from oyster; in addition, adhesion to mussel (but not oyster) haemocytes was affected by D-mannose. Mussel serum opsonins directed towards D-mannose-binding bacterial ligands were purified by affinity chromatography and were shown to mediate 01/032 interactions with M. galloprovincialis haemocytes. Nano-High Performance Liquid Chromatography-Electrospray Ionization-Tandem Mass Spectrometry (HPLC-ESI-MS/MS) analysis showed that the purified opsonin matched the protein precursor of Mytilus edulis extrapallial protein (EP). In the presence of M. galloprovincialis EP protein (MgEP), C. gigas haemocytes killed V. aestuarianus 01/032 almost as efficiently as mussel phagocytes. These findings suggest that the different sensitivity of 01/032 strain to the antibacterial activity of oyster and mussel haemolymph might partly depend on the fact that C. gigas serum lacks MgEP-like opsonins. These results represent the basis for understanding the different sensitivity to microbial infections shown by the two bivalve species.
authors: Department of Hearth, Environmental and Life Sciences (DISTAV), University of Genova, Corso Europa 26, 16132, Genova, Italy.
authors: Elisabetta
authors: E
authors: Pezzati
authors: Department of Hearth, Environmental and Life Sciences (DISTAV), University of Genova, Corso Europa 26, 16132, Genova, Italy.
authors: Laura
authors: L
authors: Canesi
authors: Department of Experimental Medicine (DIMES), University of Genova, Viale Benedetto XV 1, 16132, Genova, Italy.|Center of Excellence for Biomedical Research, University of Genova, Viale Benedetto XV 1, 16132, Genova, Italy.
authors: Gianluca
authors: G
authors: Damonte
authors: Department of Hearth, Environmental and Life Sciences (DISTAV), University of Genova, Corso Europa 26, 16132, Genova, Italy.
authors: Annalisa
authors: A
authors: Salis
authors: Department of Sciences and Technological Innovation (DiSIT), University of Piemonte Orientale 'A. Avogadro', V.le T. Michel 11, 15121, Alessandria, Italy.
authors: Francesco
authors: F
authors: Marsano
authors: Department of Hearth, Environmental and Life Sciences (DISTAV), University of Genova, Corso Europa 26, 16132, Genova, Italy.
authors: Chiara
authors: C
authors: Grande
authors: Department of Hearth, Environmental and Life Sciences (DISTAV), University of Genova, Corso Europa 26, 16132, Genova, Italy.
authors: Luigi
authors: L
authors: Vezzulli
authors: Department of Hearth, Environmental and Life Sciences (DISTAV), University of Genova, Corso Europa 26, 16132, Genova, Italy.
authors: Carla
authors: C
authors: Pruzzo
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion / Q000502:physiology; D002851:Chromatography, High Pressure Liquid; D049896:Crassostrea / Q000276:immunology / Q000382:microbiology; D006434:Hemocytes / Q000382:microbiology; D006458:Hemolymph / Q000276:immunology*; D008358:Mannose / Q000378:metabolism; D049878:Mytilus / Q000276:immunology* / Q000382:microbiology*; D009895:Opsonin Proteins / Q000097:blood* / Q000378:metabolism; D053719:Tandem Mass Spectrometry; D014733:Vibrio / Q000276:immunology*
chemical_list: D009895:Opsonin Proteins; D008358:Mannose