DEVELOPMENT OF RECOMBINANT FERTILITY VACCINE FOR FARM ANIMALS

AT PRESENT THERE IS NO SAFE, CHEAP AND EFFECTIVE COMMERCIAL METHOD TO ENHANCE FERTILITY IN FARM ANIMALS. PREVIOUS WORK AT MICHIGAN STATE UNIVERSITY HAS SHOWN THAT IMMUNONEUTRALIZATION OF INHIBIN (A GONADAL GLYCOPROTEIN THAT SUPPRESSES SECRETION OF FOLLICLE STIMULATING HORMONE) ENHANCES: OVULATION RATE IN SHEEP, HEIFERS AND GILTS; FECUNDITY IN GILTS AND SPERMATOGENESIS IN BULLS. ALTHOUGH THIS VACCINE PROVED VALUABLE AS A FERTILITY-ENHANCING AGENT IT HAS NO COMMERICIAL MERIT SINCE IT CONSISTS OF CHEMICALLY SYNTHESIZED PEPTIDES CONJUGATED TO HUMAN A-GLOBULIN AND REQUIRES THE USE OF FREUND'S ADJUVANT. THIS PROJECT PROPOSES TO CONSTRUCT AND TEST RECOMBINANT VACCINES COMPOSED OF THE B SUBUNIT (ETXB) OF THE E. COLI HEAT-LIABLE ENTEROTOXIN AND ONE OR TWO IMMUNO-DOMINANT EPITOPES OF INHIBIN. THE CHIMERIC VACCINES WILL BE CONSTRUCTED BY INSERTION OF CHEMICALLY SYNTHESIZED OLIGONUCLEOTIDES (DESIGNED TO ENCODE APPROPRIATE EPITOPES) INTO THE GENE ENCODING ETXB PROTEIN SUCH THAT THE INSERTED PEPTIDES ARE EXPOSED AT THE SURFACE OF THE ETXB MOLECULE. CHIMERIC PROTEINS WILL BE PRODUCED BY BACTERIAL FERMENTATION, PURIFIED FROM THE MEDIUM AND TESTED FOR IMMUNOGENICITY IN GILTS.