Immunocontraceptive efficacy of synthetic peptides corresponding to major antigenic determinants of chicken riboflavin carrier protein in the female rats.
OBJECTIVE
Earlier studies have demonstrated that antibodies directed towards the N-terminal (residues 10-17) and C-terminal (residues 200-207) regions on chicken riboflavin carrier protein (RCP; 219 AA) are effective in pregnancy termination in rodents and sub-human primates. In the present study, the immunocontraceptive potential of three additional immunodominant sequences comprising of residues 33-49, 64 83 and 130-147 (CYA, CED and CGE peptides, respectively) of chicken RCP was investigated.


METHODS
The three antigenic peptides were synthesized by using Fmoc chemistry. Oligoclonal antibodies were generated in rabbits. Bioneutralizing capacity of these peptides was assessed by passive and active immunoneutralization studies.


RESULTS
All the three peptides-specific antisera recognized their cognate epitopes on native RCP. When the affinity purified peptide IgG were administered on three consecutive days to pregnant rats (on days 10, 11 and 12), it was observed that the rats injected with CED and CGE-IgG failed to deliver any pups whereas the animals which received CYA IgG delivered normal pups. Active immunization of fertile female rats with CED or CGE peptide conferred protection from pregnancy.


CONCLUSIONS
These results demonstrate the presence of two additional stretches in chicken RCP which can serve as mini-vaccines.
Subramanian
S
S
Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore.
Karande
A A
AA
Adiga
P R
PR
D000595:Amino Acid Sequence; D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology; D002352:Carrier Proteins / Q000737:chemistry / Q000276:immunology*; D002645:Chickens; D003269:Contraception, Immunologic / Q000379:methods*; D003271:Contraceptive Agents, Female / Q000276:immunology*; D005260:Female; D016056:Immunodominant Epitopes / Q000737:chemistry / Q000276:immunology*; D026901:Membrane Transport Proteins; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000276:immunology*; D011247:Pregnancy; D017433:Protein Structure, Secondary; D051381:Rats; D017208:Rats, Wistar; D013601:T-Lymphocytes / Q000276:immunology
D002352:Carrier Proteins; D003271:Contraceptive Agents, Female; D016056:Immunodominant Epitopes; D026901:Membrane Transport Proteins; D010446:Peptide Fragments; C019079:riboflavin-binding protein