Characterisation of proteins in excretory/secretory products collected from salmon lice, Lepeophtheirus salmonis

Citation

Hamilton S, McLean K, Monaghan S, McNair C, Inglis NF, McDonald HC, Adams A, Richards R, Roy W, Smith P, Bron J, Nisbet A & Knox D (2018) Characterisation of proteins in excretory/secretory products collected from salmon lice, Lepeophtheirus salmonis. Parasites and Vectors, 11 (1), Art. No.: 294. https://doi.org/10.1186/s13071-018-2885-6

Abstract
Background  The salmon louse, Lepeophtheirus salmonis, is an ectoparasitic copepod which feeds on the mucus, skin and blood of salmonid fish species. The parasite can persist on the surface of the fish without any effective control being exerted by the host immune system. Other ectoparasitic invertebrates produce compounds in their saliva, excretions and/or secretions which modulate the host immune responses allowing them to remain on or in the host during development. Similarly, compounds are produced in secretions of L. salmonis which are thought to be responsible for immunomodulation of the host responses as well as other aspects of crucial host-parasite interactions.  Methods  In this study we have identified and characterised the proteins in the excretory/secretory (E/S) products of L. salmonis using LC-ESI-MS/MS.  Results  In total 187 individual proteins were identified in the E/S collected from adult lice and pre-adult sea lice. Fifty-three proteins, including 13 serine-type endopeptidases, 1 peroxidase and 5 vitellogenin-like proteins were common to both adult and pre-adult E/S products. One hundred and seven proteins were identified in the adult E/S but not in the pre-adult E/S and these included serine and cysteine-type endopeptidases, vitellogenins, sphingomyelinase and calreticulin. A total of 27 proteins were identified in pre-adult E/S products but not in adult E/S.  Conclusions  The assigned functions of these E/S products and the potential roles they play in host-parasite interaction is discussed.

Keywords
Lepeophtheirus salmonis; Excretory/secretory (E/S) products; Immunomodulators; Sea lice

Journal
Parasites and Vectors: Volume 11, Issue 1

People

Professor James Bron

Professor, Institute of Aquaculture

Dr Sean Monaghan

Senior Lecturer, Institute of Aquaculture

Professor Randolph Richards

Emeritus Professor, Institute of Aquaculture