title: A novel antigen from Anaplasma marginale: characterization, expression and preliminary evaluation of the recombinant protein.
abstract: Through a process of protein fractionation and vaccination we previously identified four native antigens that confer a degree of protection against challenge with Anaplasma marginale. One of these, Ana 29 has been successfully cloned and sequenced using degenerate primers designed to N-terminal and internal peptide sequences. The full-length gene codes for a protein with a theoretical molecular weight of 27 kDa and pI 8.6. The sequence is highly conserved, showing 99% identity between two Australian and an American isolate of A. marginale. The gene sequences from these isolates also share 99% identity with the strain of Anaplasma centrale used in the commercial Australian vaccine. Protein prediction algorithms suggest the native protein is an integral membrane protein. This protein has been over-expressed and purified from Escherichia coli and used in vaccination trials in cattle using two adjuvants. The initial results from the trial show a significant level of protection was obtained with one adjuvant; in comparison, the second adjuvant slightly aggravated the disease. Preliminary data suggests a good correlation between the induction of an IgG2 response and protection.
authors.affiliation: Cooperative Research Center for Vaccine Technology and CSIRO Livestock Industries, Queensland Biosciences Precinct, 306 Carmody Road, QLD 4067, St. Lucia, Australia. shelly.hope@csiro.au
authors.forename: Michelle
authors.initials: M
authors.lastname: Hope
authors.forename: George
authors.initials: G
authors.lastname: Riding
authors.forename: Moira
authors.initials: M
authors.lastname: Menzies
authors.forename: Peter
authors.initials: P
authors.lastname: Willadsen
mesh_terms: D000595:Amino Acid Sequence; D000709:Anaplasma / Q000276:immunology*; D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis; D000942:Antigens, Bacterial / Q000096:biosynthesis / Q000737:chemistry* / Q000276:immunology; D001483:Base Sequence; D015139:Blotting, Southern; D002417:Cattle; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000096:biosynthesis / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D008969:Molecular Sequence Data; D012313:RNA / Q000235:genetics / Q000302:isolation & purification; D014611:Vaccination; D014614:Vaccines, Synthetic / Q000096:biosynthesis / Q000737:chemistry / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D018076:DNA, Complementary; D014614:Vaccines, Synthetic; D012313:RNA