title: Vaccination with recombinant adenovirus expressing multi-stage antigens of Toxoplasma gondii by the mucosal route induces higher systemic cellular and local mucosal immune responses than with other vaccination routes.
abstract: Toxoplasmosis caused by Toxoplasma gondii, an obligate intracellular protozoan, is a cause of congenital disease and abortion in humans and animals. Various vaccination strategies against toxoplasmosis in rodent models have been used in the past few decades; however, effective vaccines remain a challenge. A recombinant adenovirus vaccine expressing ubiquitin-conjugated multi-stage antigen segments (Ad-UMAS) derived from different life-cycle stages of T. gondii was constructed previously. Here, we compared the immune responses and protection effects in vaccination of mice with Ad-UMAS by five vaccination routes including intramuscular (i.m.), intravenous (i.v.), subcutaneous (s.c.), intraoral (i.o.), and intranasal (i.n.). Much higher levels of T. gondii-specific IgG and IgA antibodies were detected in the sera of the intraoral and intranasal vaccination groups on day 49 compared with controls (p < 0.05). The percentages of CD8+T-cells in mice immunized intranasally and intraorally were larger than in mice immunized intramuscularly (p < 0.05). The highest level of IL-2 and IFN-γ was detected in the group with nasal immunization, and splenocyte proliferation activity was significantly enhanced in mice immunized via the oral and nasal routes. Furthermore, the higher survival rate (50%) and lower cyst numbers observed in the intraoral and intranasal groups all indicate that Ad-UMAS is far more effective in protecting mice against T. gondii infection via the mucosal route. Ad-UMAS could be an effective and safe mucosal candidate vaccine to protect animals and humans against T. gondii infection.
authors.affiliation: Department of Human Parasitology, Shandong University, School of Medicine, No. 44 Wenhuaxi Road, Jinan, Shandong 250012, P.R. China.
authors.forename: Ting
authors.initials: T
authors.lastname: Wang
authors.affiliation: Department of Human Parasitology, Shandong University, School of Medicine, No. 44 Wenhuaxi Road, Jinan, Shandong 250012, P.R. China.
authors.forename: Huiquan
authors.initials: H
authors.lastname: Yin
authors.affiliation: Department of Human Parasitology, Shandong University, School of Medicine, No. 44 Wenhuaxi Road, Jinan, Shandong 250012, P.R. China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.affiliation: Shandong Xiehe University, No. 6277 Jiqing Road, Jinan, Shandong 250107, P.R. China.
authors.forename: Lingxiao
authors.initials: L
authors.lastname: Zhao
authors.affiliation: Department of Human Parasitology, Shandong University, School of Medicine, No. 44 Wenhuaxi Road, Jinan, Shandong 250012, P.R. China.
authors.forename: Xiahui
authors.initials: X
authors.lastname: Sun
authors.affiliation: Department of Human Parasitology, Shandong University, School of Medicine, No. 44 Wenhuaxi Road, Jinan, Shandong 250012, P.R. China.
authors.forename: Hua
authors.initials: H
authors.lastname: Cong
mesh_terms: D000256:Adenoviridae; D000281:Administration, Intranasal; D058956:Administration, Mucosal; D000284:Administration, Oral; D000818:Animals; D000913:Antibodies, Protozoan / Q000096:biosynthesis / Q000097:blood; D001921:Brain / Q000469:parasitology; D049109:Cell Proliferation; D016207:Cytokines / Q000378:metabolism; D005260:Female; D005822:Genetic Vectors; D007111:Immunity, Cellular; D018928:Immunity, Mucosal; D007074:Immunoglobulin G / Q000096:biosynthesis / Q000097:blood; D008214:Lymphocytes / Q000166:cytology / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D016052:Protozoan Vaccines / Q000008:administration & dosage* / Q000276:immunology; D013047:Specific Pathogen-Free Organisms; D013154:Spleen / Q000166:cytology / Q000276:immunology; D014122:Toxoplasma / Q000276:immunology* / Q000472:pathogenicity; D014123:Toxoplasmosis / Q000517:prevention & control*; D014611:Vaccination / Q000379:methods*; D014614:Vaccines, Synthetic / Q000008:administration & dosage / Q000276:immunology
chemical_list: D000913:Antibodies, Protozoan; D016207:Cytokines; D007074:Immunoglobulin G; D016052:Protozoan Vaccines; D014614:Vaccines, Synthetic