title: Oligomannose-coated liposome-entrapped dense granule protein 7 induces protective immune response to Neospora caninum in cattle.
abstract: Neospora caninum is an intracellular protozoan parasite that causes abortion in cows. Vaccination is an important strategy for control of neosporosis, and a safe and effective vaccine suitable for cattle is required. Dense granule protein 7 of N. caninum (NcGRA7) is a secretory protein with high antigenicity in hosts. We demonstrated previously that NcGRA7 entrapped in liposomes coated with mannotriose (M3-NcGRA7) could induce a parasite-specific T-helper type 1 immune response and produce humoral antibodies that resulted in increased offspring survival and decreased infection in the brains of mice dams. In the present study, the efficacy of M3-NcGRA7 as a vaccine candidate against N. caninum has been evaluated in cattle (n=12). Cattle were immunized with M3-NcGRA7 containing 50 μg (n=4) or 200 μg NcGRA7 (n=4) subcutaneously twice with a 4-week interval and all cattle including the non-immunized controls (n=4) were inoculated with 10(7) tachyzoites of Nc-1 strain 27 days after the second immunization and euthanized at 85-87 days post infection (dpi). In immunized cattle, NcGRA7-specific antibody production and IFN-γ production in PBMC was induced before challenge. At 3 dpi, body temperature and concentration of serum IFN-γ tended to be higher in control cattle than in the immunized cattle. Furthermore, the parasite load in the brain significantly decreased in cattle immunized with 50 μg M3-NcGRA7 compared with controls. These results suggest that M3-NcGRA7 can induce protective immune responses to N. caninum tachyzoites in cattle, which could lead to practical application of safe and effective subunit vaccines.
authors.affiliation: National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido 080-8555, Japan.
authors.forename: Maki
authors.initials: M
authors.lastname: Nishimura
authors.forename: Junko
authors.initials: J
authors.lastname: Kohara
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Kuroda
authors.forename: Jun
authors.initials: J
authors.lastname: Hiasa
authors.forename: Sachi
authors.initials: S
authors.lastname: Tanaka
authors.forename: Yoshikage
authors.initials: Y
authors.lastname: Muroi
authors.forename: Naoya
authors.initials: N
authors.lastname: Kojima
authors.forename: Hidefumi
authors.initials: H
authors.lastname: Furuoka
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Nishikawa
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood / Q000276:immunology; D000953:Antigens, Protozoan / Q000276:immunology*; D002417:Cattle; D002418:Cattle Diseases / Q000276:immunology* / Q000469:parasitology; D003048:Coccidiosis / Q000276:immunology* / Q000469:parasitology / Q000662:veterinary*; D007371:Interferon-gamma / Q000097:blood / Q000378:metabolism; D008081:Liposomes / Q000276:immunology; D008297:Male; D018688:Neospora / Q000276:immunology; D016052:Protozoan Vaccines / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology; D014312:Trisaccharides / Q000276:immunology; D014611:Vaccination / Q000662:veterinary
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D008081:Liposomes; D016052:Protozoan Vaccines; D014312:Trisaccharides; C023872:mannotriose; D007371:Interferon-gamma
keywords: Cattle; Dense granule protein 7; Neospora caninum; Oligomannose-coated liposome; Vaccine