title: Humoral immune responses against gonadotropin releasing hormone elicited by immunization with phage-peptide constructs obtained via phage display.
abstract: Phage display is based on genetic engineering of phage coat proteins resulting in fusion peptides displayed on the surface of phage particles. The technology is widely used for generation of phages with novel characteristics for numerous applications in biomedicine and far beyond. The focus of this study was on development of phage-peptide constructs that stimulate production of antibodies against gonadotropin releasing hormone (GnRH). Phage-peptide constructs that elicit production of neutralizing GnRH antibodies can be used for anti-fertility and anti-cancer applications. Phage-GnRH constructs were generated via selection from a phage display library using several types of GnRH antibodies as selection targets. Such phage constructs were characterized for sequence similarities to GnRH peptide and frequency of their occurrence in the selection rounds. Five of the constructs with suitable characteristics were tested in mice as a single dose 5×10(11) virions (vir) vaccine and were found to be able to stimulate production of GnRH-specific antibodies, but not to suppress testosterone (indirect indicator of GnRH antibody neutralizing properties). Next, one of the constructs was tested at a higher dose of 2×10(12) vir per mouse in combination with a poly(lactide-co-glycolide) (PLGA)-based adjuvant. This resulted in multifold increase in GnRH antibody production and significant reduction of serum testosterone, indicating that antibodies produced in response to the phage-GnRH immunization possess neutralizing properties. To achieve optimal immune responses for desired applications, phage-GnRH constructs can be modified with respect to flanking sequences of GnRH-like peptides displayed on phage. Anticipated therapeutic effects also might be attained using optimized phage doses, a combination of several constructs in a single treatment, or application of adjuvants and advanced phage delivery systems.
authors.affiliation: Scott-Ritchey Research Center, College of Veterinary Medicine, Auburn University, Auburn, AL 36849 USA. Electronic address: samoyam@auburn.edu.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Samoylov
authors.affiliation: Scott-Ritchey Research Center, College of Veterinary Medicine, Auburn University, Auburn, AL 36849 USA. Electronic address: cochram@auburn.edu.
authors.forename: Anna
authors.initials: A
authors.lastname: Cochran
authors.affiliation: Laboratory Animal Health, College of Veterinary Medicine, Auburn University, Auburn, AL 36849, USA. Electronic address: schembe@auburn.edu.
authors.forename: Bettina
authors.initials: B
authors.lastname: Schemera
authors.affiliation: Department of Animal and Rangeland Sciences, Oregon State University, Corvallis, OR 97331, USA. Electronic address: Michelle.Kutzler@oregonstate.edu.
authors.forename: Michelle
authors.initials: M
authors.lastname: Kutzler
authors.affiliation: Department of Animal and Rangeland Sciences, Oregon State University, Corvallis, OR 97331, USA. Electronic address: cdonovan@ucdavis.edu.
authors.forename: Caitlin
authors.initials: C
authors.lastname: Donovan
authors.affiliation: Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn, AL 36849, USA. Electronic address: petreva@auburn.edu.
authors.forename: Valery
authors.initials: V
authors.lastname: Petrenko
authors.affiliation: Scott-Ritchey Research Center, College of Veterinary Medicine, Auburn University, Auburn, AL 36849 USA; Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL 36849, USA. Electronic address: bartoff@auburn.edu.
authors.forename: Frank
authors.initials: F
authors.lastname: Bartol
authors.affiliation: Scott-Ritchey Research Center, College of Veterinary Medicine, Auburn University, Auburn, AL 36849 USA; Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn, AL 36849, USA. Electronic address: samoiti@auburn.edu.
authors.forename: Tatiana
authors.initials: T
authors.lastname: Samoylova
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies / Q000276:immunology; D000917:Antibody Formation / Q000276:immunology; D001435:Bacteriophages / Q000378:metabolism*; D002415:Cats; D061505:Cell Surface Display Techniques / Q000379:methods*; D004285:Dogs; D004797:Enzyme-Linked Immunosorbent Assay; D007987:Gonadotropin-Releasing Hormone / Q000276:immunology*; D056724:Immunity, Humoral; D007114:Immunization; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry / Q000276:immunology*; D013739:Testosterone / Q000097:blood
chemical_list: D000906:Antibodies; D010455:Peptides; D007987:Gonadotropin-Releasing Hormone; D013739:Testosterone
keywords: Contraception; Filamentous phage; GnRH antibodies; Gonadotropin releasing hormone; Hormone-dependent reproductive cancers; Phage display