title: Isolation of Neospora caninum genes detected during a chronic murine infection.
abstract: In order to isolate genes coding for antigens of Neospora caninum which are recognised by the host immune system during a chronic murine infection, a cDNA library was immunoscreened with pooled sera from mice which survived three independent infections by N. caninum. Two new genes from N. caninum were isolated and expressed in Escherichia coli. The genes identified include one homologous to GRA1 of Toxoplasma gondii, plus another (NCP20) previously unknown in any taxon. Both genes encode small polypeptides which induced an IgG response in the mouse and were also recognised by IgG from a cow chronically infected with N. caninum. These results are consistent with the hypothesis that the polypeptides encoded by these genes are a target for the host immune system during chronic infections of N. caninum.
authors.affiliation: Molecular Parasitology Unit, Department of Cell and Molecular Biology, University of Technology, Sydney, Westbourne St., NSW 2065, Gore Hill, Australia.
authors.forename: R A
authors.initials: RA
authors.lastname: Atkinson
authors.forename: C
authors.initials: C
authors.lastname: Ryce
authors.forename: C M
authors.initials: CM
authors.lastname: Miller
authors.forename: S
authors.initials: S
authors.lastname: Balu
authors.forename: P A
authors.initials: PA
authors.lastname: Harper
authors.forename: J T
authors.initials: JT
authors.lastname: Ellis
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000953:Antigens, Protozoan / Q000032:analysis; D003048:Coccidiosis / Q000235:genetics / Q000662:veterinary*; D018076:DNA, Complementary / Q000737:chemistry / Q000302:isolation & purification; D016054:DNA, Protozoan / Q000737:chemistry / Q000302:isolation & purification*; D004591:Electrophoresis, Polyacrylamide Gel / Q000662:veterinary; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D018688:Neospora / Q000235:genetics*; D016366:Open Reading Frames; D012376:Rodent Diseases / Q000235:genetics*; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014122:Toxoplasma
chemical_list: D000953:Antigens, Protozoan; D018076:DNA, Complementary; D016054:DNA, Protozoan; C412913:GRA1 antigen