Immunocontraceptive potential of major antigenic determinants of chicken riboflavin carrier protein in the female rat

Earlier investigations have demonstrated that antibodies generated against the N-terminal (10-17) and C-terminal (200-207) ends of chicken riboflavin carrier protein (RCP; 219 AA), but not towards the internal region (172-179 ), curtail pregnancy establishment in rodents and sub-human primates. In th ose studies, epitope peptides conjugated to diphtheria toroid were used as immunogens. In the present study, linkage of these sequences to extraneous carriers was avoided to rule out the possibility of carrier-mediated suppre ssion of hapten-specific antibody production in long-term immune response. The ability of these three free peptides to function as minivaccines was ex amined and the functional importance of these sequences in pregnancy establ ishment in rodents were evaluated. The results obtained reveal that the pep tides YGC (residues 3-24) and HAC (residues 200-219) serve as immunocontrac eptive vaccines. (C) 2000 Elsevier Science Ltd. All rights reserved.