title: Induction of castration by immunization of male dogs with recombinant gonadotropin-releasing hormone (GnRH)-canine distemper virus (CDV) T helper cell epitope p35.
abstract: Immunocastration is a considerable alternative to a surgical castration method especially in male animal species for alleviating unwanted male behaviors and characteristics. Induction of high titer of antibody specific for gonadotropin-releasing hormone (GnRH) correlates with the regression of testes. Fusion proteins composed of canine GnRH and T helper (Th) cell epitope p35 originated from canine distemper virus (CDV) F protein and goat rotavirus VP6 protein were produced in E. coli. When these fusion proteins were injected to male dogs which were previously immunized with CDV vaccine, the fusion protein of GnRH-CDV Th cell epitope p35 induced much higher antibody than that of GnRH-rotavirus VP6 protein or GnRH alone. The degeneration of spermatogenesis was also verified in the male dogs immunized with the fusion protein of GnRH-CDV Th cell epitope p35. These results indicate that canine GnRH conjugated to CDV Th cell epitope p35 acted as a strong immunogen and the antibody to GnRH specifically neutralized GnRH in the testes. This study also implies a potential application of GnRH-based vaccines for immunocastration of male pets.
authors.affiliation: Department of Infectious Diseases, College of Veterinary Medicine, Konkuk University, Kwangjin-gu, Seoul 143-701, Korea.
authors.forename: Mi-Jeong
authors.initials: MJ
authors.lastname: Jung
authors.forename: Young-Chan
authors.initials: YC
authors.lastname: Moon
authors.forename: Ik-Hyun
authors.initials: IH
authors.lastname: Cho
authors.forename: Jung-Yong
authors.initials: JY
authors.lastname: Yeh
authors.forename: Sun-Eui
authors.initials: SE
authors.lastname: Kim
authors.forename: Wha-Seok
authors.initials: WS
authors.lastname: Chang
authors.forename: Seung-Young
authors.initials: SY
authors.lastname: Park
authors.forename: Chang-Seon
authors.initials: CS
authors.lastname: Song
authors.forename: Hwi-Yool
authors.initials: HY
authors.lastname: Kim
authors.forename: Keun-Kyu
authors.initials: KK
authors.lastname: Park
authors.forename: Steven
authors.initials: S
authors.lastname: McOrist
authors.forename: In-Soo
authors.initials: IS
authors.lastname: Choi
authors.forename: Joong-Bok
authors.initials: JB
authors.lastname: Lee
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies / Q000097:blood; D001483:Base Sequence; D003269:Contraception, Immunologic / Q000379:methods / Q000662:veterinary*; D004217:Distemper Virus, Canine / Q000276:immunology*; D004285:Dogs / Q000276:immunology / Q000502:physiology*; D018984:Epitopes, T-Lymphocyte / Q000276:immunology*; D005298:Fertility / Q000276:immunology; D007987:Gonadotropin-Releasing Hormone / Q000737:chemistry / Q000276:immunology*; D008297:Male; D008969:Molecular Sequence Data; D009929:Organ Size; D011994:Recombinant Proteins / Q000276:immunology; D013091:Spermatogenesis / Q000276:immunology; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology; D013737:Testis / Q000276:immunology; D022642:Vaccines, Contraceptive / Q000276:immunology
chemical_list: D000906:Antibodies; D018984:Epitopes, T-Lymphocyte; D011994:Recombinant Proteins; D022642:Vaccines, Contraceptive; D007987:Gonadotropin-Releasing Hormone