Evaluation of two GnRH-I based vaccine formulations on the testes function of entire Suffolk cross ram lambs

• Published in: Vaccine Vol. 24; no. 16; pp. 3172 - 3183
• Main Authors: Earl, Elizabeth R., Waterston, Mary M., Aughey, Elizabeth, Harvey, Michael J.A., Matschke, Christian, Colston, Angela, Ferro, Valerie A.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 12-04-2006; Elsevier; Elsevier Limited
• Subjects: Adjuvants, Immunologic; Animal vaccines; Animals; Anti-fertility; Antibodies - blood; Applied microbiology; Biological and medical sciences; Contraception, Immunologic - methods; Diphtheria; Diphtheria Toxoid - administration & dosage; Diphtheria Toxoid - immunology; Enzyme-Linked Immunosorbent Assay; Fertility; Follicle Stimulating Hormone - blood; Fundamental and applied biological sciences. Psychology; GnRH; Gonadotropin-Releasing Hormone - chemistry; Gonadotropin-Releasing Hormone - immunology; Histocytochemistry; Immunization; Immunization Schedule; Injections; Lactic Acid; Male; Microbiology; Peptides; Polyglycolic Acid; Polymers; Quillaja Saponins; Saponins - immunology; Sheep; Sheep - physiology; Spermatogenesis; Testicular Hormones - blood; Testis - cytology; Testosterone; Testosterone - blood; Tetanus; Tetanus Toxoid - administration & dosage; Tetanus Toxoid - immunology; Vaccine; Vaccines, antisera, therapeutical immunoglobulins and monoclonal antibodies (general aspects); Vaccines, Conjugate - chemistry; Vaccines, Conjugate - immunology; Vaccines, Contraceptive - administration & dosage; United Kingdom > UK; Australia; Anti-fertility; GnRH; Vaccine; Anti-fertility: Vaccine; Fertility
• ISSN: 0264-410X; 1873-2518
• DOI: 10.1016/j.vaccine.2006.01.041

A modified GnRH peptide (CHWSYGLRPG-NH
2) was conjugated to tetanus toxoid (TT) or diphtheria toxoid (DT) and formulated with Quil A saponin or a sustained release injectible PLGA (poly(lactide-
co-glycolide)/triacetin). For the Quil A formulations, two administrations of TT conjugate at 3-weekly intervals were followed by two booster injections with the DT conjugate in entire ram lambs. With the PLGA formulations, only two injections were administered; the first containing TT and the second DT at 6-weekly intervals. Evaluation was carried out by comparing the specific antibody levels produced in relationship to hormone profiles and testicular changes. The Quil A formulation was considered the most effective, as it caused significant reduction in testosterone and follicle stimulating hormone levels, resulting in marked suppression of spermatogenesis.