Neospora caninum: Identification of 19-, 38-, and 40-kDa Surface Antigens and a 33-kDa Dense Granule Antigen Using Monoclonal Antibodies

• Published in: Experimental parasitology Vol. 92; no. 2; pp. 109 - 119
• Main Authors: Schares, G., Dubremetz, J.F., Dubey, J.P., Bärwald, A., Loyens, A., Conraths, F.J.
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 01.06.1999; Elsevier
• Subjects: Animals; Antibodies, Monoclonal - immunology; Antigens, Protozoan - analysis; Antigens, Protozoan - chemistry; Antigens, Surface - analysis; Antigens, Surface - chemistry; Biochemistry. Physiology. Immunology. Molecular biology; Biological and medical sciences; Blotting, Western; Cercopithecus aethiops; characterization; Epitopes - analysis; Fluorescent Antibody Technique; Fundamental and applied biological sciences. Psychology; Hybridomas; identification; Immunoenzyme Techniques; life cycle (organisms); Mice; Mice, Inbred BALB C; Microscopy, Immunoelectron; Molecular Weight; monoclonal antibodies; Neospora - immunology; Neospora - ultrastructure; Neospora caninum; Precipitin Tests; Protozoa; surface antigens; Toxoplasma gondii; Vero Cells; phosphate-buffered saline (PBS); glycosyl phosphatidylinositol (GPI); tachyzoite; parasitic; immunoelectron microscopy (IEM); monoclonal antibody (MAB); Nc-p43; Neospora caninum; parasitophorous vacuole; sodium dodecyl sulfate-polyacrylamide electrophoresis (SDS-PAGE); NcDG1; membrane antigen; Apicomplexa; bradyzoite; fetal bovine serum (FBS); fluorescein isothiocyanate (FITC); protozoa; immunofluorescence assay (IFA); Toxoplasma gondii; 1,4 diazobicyclo-[2,2,2]-octane (DABCO); dense granule; Nc-p36; bovine serum albumine (BSA); phosphatidylinositol-specific phospholipase C (PI-PLC); 2-mercaptoethanol (ME); 1,4-piperazinediethanesulfonic acid (Pipes); SAG1; Protozoa; Life history; Parasite; Identification; Species specificity; Monoclonal antibody; Cell surface; Antigen; Pathogenic; Developmental stage; Localization
• ISSN: 0014-4894; 1090-2449
• DOI: 10.1006/expr.1999.4403

Schares, G., Dubremetz, J. F., Dubey, J. P., Bärwald, A., Loyens, A., and Conraths, F. J. 1999. Neospora caninum: Identification of 19-, 38-, and 40-kDa surface antigens and a 33-kDa dense granule antigen using monoclonal antibodies. Experimental Parasitology92, 109–119. Neospora caninum, a coccidian parasite closely related to Toxoplasma gondii, can infect a broad host range and is regarded as an important cause of bovine abortion worldwide. In the present study, four antigens of N. caninum were partially characterized using monoclonal antibodies. Immunofluorescence of viable tachyzoites as well as the immunoprecipitation of antigens extracted from tachyzoites previously labeled by surface biotinylation revealed that three of these antigens with apparent molecular weights of 40, 38, and 19 kDa are located in the outer surface membrane of this parasite stage. Further evidence for the surface localization of the 38-kDa antigen was obtained by immunoelectron microscopy. In addition to the surface molecules, an antigen located in dense granules and in the tubular network of the parasitophorous vacuole was detected by another monoclonal antibody. When tachyzoite antigens separated under nonreducing conditions were probed on Western blots, this antibody reacted mainly with a 33-kDa antigen. Immunohistochemical analysis of infected tissue sections indicated that the 33-kDa dense granule antigen is present in both tachyzoites and bradyzoites, while the 38-kDa surface antigen from tachyzoites seems to be absent in bradyzoites.