title: A recombinant subunit vaccine for the control of ovine psoroptic mange (sheep scab).
abstract: Sheep scab, caused by infestation with the mite Psoroptes ovis, is highly contagious, causing intense pruritus and represents a major welfare and economic concern. Disease control strategies rely upon chemotherapy, however, sustainability is questionable due to issues of chemical residues, eco-toxicity and acaricide resistance. Control by vaccination is supported by demonstration of protective immunity in sheep previously infested with P. ovis. We identified vaccine candidates for P. ovis based on: (1) antigens selected by their interaction with host signalling pathways and the host immune-response; and (2) those shown to be either immunogenic or involved in mite feeding. This resulted in the development and validation, in repeated immunisation and challenge trials, of a seven recombinant protein sub-unit cocktail vaccine. Sheep were inoculated on three occasions, 2 weeks apart, along with QuilA adjuvant. Vaccination resulted in highly significant reductions in both lesion size (up to 63%) and mite numbers (up to 56%) following challenge. Mean lesion size in vaccinates was significantly smaller than controls from 1 week post infestation (wpi) until the end of the experiment at 6 wpi. All antigens elicited serum IgG responses following immunisation and prior to infestation, whereas controls did not produce antigen-specific IgG during the pre-infestation period. Vaccinated animals showed an amnestic response, with levels of antigen-specific IgG against muGST, Pso o 1 and Pso o 2 increasing following infestation. This vaccine represents the greatest reduction in lesion size to date with a sheep scab vaccine, providing encouragement for future production of a commercially-viable means of immunoprophylaxis.
authors: Moredun Research Institute, Pentlands Science Park, Bush Loan, Edinburgh, Midlothian, Scotland, EH26 0PZ, UK. stewart.burgess@moredun.ac.uk.
authors: Stewart T G
authors: ST
authors: Burgess
authors: Moredun Research Institute, Pentlands Science Park, Bush Loan, Edinburgh, Midlothian, Scotland, EH26 0PZ, UK. francesca.nunn@moredun.ac.uk.
authors: Francesca
authors: F
authors: Nunn
authors: Biomathematics & Statistics Scotland, JCMB, King's Buildings, Peter Guthrie Tait Road, Edinburgh, Scotland, EH9 3FD, UK. mintu.nath@bioss.ac.uk.
authors: Mintu
authors: M
authors: Nath
authors: Moredun Research Institute, Pentlands Science Park, Bush Loan, Edinburgh, Midlothian, Scotland, EH26 0PZ, UK. david.frew@moredun.ac.uk.
authors: David
authors: D
authors: Frew
authors: Moredun Research Institute, Pentlands Science Park, Bush Loan, Edinburgh, Midlothian, Scotland, EH26 0PZ, UK. beth.wells@moredun.ac.uk.
authors: Beth
authors: B
authors: Wells
authors: Moredun Research Institute, Pentlands Science Park, Bush Loan, Edinburgh, Midlothian, Scotland, EH26 0PZ, UK. edward.marr@moredun.ac.uk.
authors: Edward J
authors: EJ
authors: Marr
authors: Moredun Research Institute, Pentlands Science Park, Bush Loan, Edinburgh, Midlothian, Scotland, EH26 0PZ, UK. john.huntley@moredun.ac.uk.
authors: John F
authors: JF
authors: Huntley
authors: Moredun Research Institute, Pentlands Science Park, Bush Loan, Edinburgh, Midlothian, Scotland, EH26 0PZ, UK. tom.mcneilly@moredun.ac.uk.
authors: Tom N
authors: TN
authors: McNeilly
authors: Moredun Research Institute, Pentlands Science Park, Bush Loan, Edinburgh, Midlothian, Scotland, EH26 0PZ, UK. alasdair.nisbet@moredun.ac.uk.
authors: Alasdair J
authors: AJ
authors: Nisbet
mesh_terms: D000818:Animals; D000941:Antigens / Q000276:immunology; D060829:Arthropod Proteins / Q000276:immunology; D008924:Mite Infestations / Q000469:parasitology / Q000517:prevention & control / Q000662:veterinary*; D040042:Psoroptidae / Q000502:physiology*; D012756:Sheep; D012757:Sheep Diseases / Q000469:parasitology / Q000517:prevention & control*; D014611:Vaccination / Q000662:veterinary*; D014612:Vaccines / Q000627:therapeutic use*; D022223:Vaccines, Subunit / Q000627:therapeutic use; D014614:Vaccines, Synthetic / Q000627:therapeutic use
chemical_list: D000941:Antigens; D060829:Arthropod Proteins; D014612:Vaccines; D022223:Vaccines, Subunit; D014614:Vaccines, Synthetic