The design, production, purification, and testing of a chimeric antigen protein to be used as an immunosterilant in domestic animals

A method is described for the design of a protein that incorporates a carrier molecule fused to a novel tandem repeat configuration of a 10 amino acid peptide, Gonadotrophin Releasing Hormone (GnRH), which normally would not be immunogenic because it is a self-antigen. This molecule can be produced with adequate yield in E. coli bacteria and purified to homogeneity using standard chromatographic procedures. When low doses of the molecule are injected with an appropriate adjuvant, rats and pigs respond by producing high antibody titres to GnRH. The immunization results in a dramatic reduction of pituitary gonadotrophin secretion and, as a consequence, reduces steroid secretion and causes gonadal atrophy. Keywords: GnRH, fusion protein, immunosterilant, vaccine