Comparative efficacy of immunization with inactivated whole tachyzoites versus a tachyzoite-bradyzoite mixture against neosporosis in mice

• Published in: Parasitology Vol. 138; no. 11; pp. 1372 - 1383
• Main Authors: ROJO-MONTEJO, S., COLLANTES-FERNÁNDEZ, E., RODRÍGUEZ-MARCOS, S., PÉREZ-ZABALLOS, F., LÓPEZ-PÉREZ, I., PRENAFETA, A., ORTEGA-MORA, L. M.
• Format: Journal Article
• Language: English
• Published: Cambridge, UK Cambridge University Press 01.09.2011
• Subjects: Adjuvants, Immunologic - administration & dosage; Adjuvants, Immunologic - chemistry; Aluminum; Animals; Animals, Newborn; Antibodies, Protozoan - biosynthesis; Antibodies, Protozoan - immunology; Biological and medical sciences; Cattle; Coccidiosis - immunology; Coccidiosis - parasitology; Coccidiosis - prevention & control; Economic impact; Enzyme-Linked Immunosorbent Assay; Female; Fundamental and applied biological sciences. Psychology; General aspects; General aspects and techniques. Study of several systematic groups. Models; Immune response; Immunity, Humoral - drug effects; Immunization; Immunization - mortality; Infectious Disease Transmission, Vertical - prevention & control; Interferon-gamma - analysis; Interferon-gamma - biosynthesis; Interleukin-4 - analysis; Interleukin-4 - biosynthesis; Invertebrates; Life Cycle Stages - immunology; Mice; Mice, Inbred BALB C; Neonates; Neospora - immunology; Neospora caninum; Parasites; Polymerase Chain Reaction; Pregnancy; Protozoan Vaccines - administration & dosage; Protozoan Vaccines - immunology; Protozoan Vaccines - metabolism; Recombinant Proteins - immunology; Recombinant Proteins - metabolism; Vaccines; Vaccines, Inactivated - administration & dosage; Vaccines, Inactivated - immunology; Vaccines, Inactivated - metabolism; tachyzoite; bradyzoite; inactivated vaccine; mice; Neospora caninum; Protozoa; Apicomplexa; Immunization; Rodentia; Parasite; Vaccine; Vertebrata; Mammalia; Mouse
• ISSN: 0031-1820; 1469-8161
• DOI: 10.1017/S0031182011001156

The worldwide economic impact of Neospora caninum infection has caused the development of effective vaccines to become one of the main goals in the field of neosporosis research. In this study, the protection conferred by antigens from inactivated whole tachyzoites (TZ) and a tachyzoite-bradyzoite mixture (TZ-BZ) of N. caninum (Nc-Spain7 isolate) incorporated into a water-in-oil emulsion (W/O) and aluminium hydroxide-ginseng extract (Al/G) was evaluated in mouse models of congenital and cerebral N. caninum infection. Immunization with TZ-BZ induced congenital and cerebral neosporosis exacerbation that was mainly characterized by reduced neonatal median survival time and increased parasite presence in adult mouse brains. The immune response of mice immunized with TZ-BZ was characterized by an increase in IFN-γ expression prior to challenge and an increase in IL-4 expression accompanied with significantly higher levels of antibodies against 2 recombinant bradyzoite-specific proteins (rNcSAG4 and rNcBSR4) after challenge. Immunization with TZ in W/O significantly reduced neonatal mortality, vertical transmission as well as parasite presence in adult mouse brains and induced a strong humoral immune response. The current study demonstrates the critical role of stage-specific antigens and adjuvants on the development of effective inactivated vaccines for the prevention of N. caninum infection.