Chimeric peptide immunogens

Abstract

Chimeric peptide epitopes can serve as effective immunogens against hormones and other small peptides or proteins. Thus, immunogenic peptides are selected from promiscuous Th epitopes and synthesized together with self antigenic peptide sequences fused with or without end to end spacer peptide interconnections. A peptide sequence which may be of the gonadotropin releasing hormone is linked with an immunogenic peptide sequence selected from a promiscuous Th-epitope of measles virus protein F, tetanus toxoid, or malaria protein CSP. Compositions of the chimeric immunogen are found effective in eliciting high and specific anti-GnRH antibody titers.

1 - 16 . (canceled)  
     
     
         17 . A method of inducing specific antibodies against GnRH in an animal or a human comprising administering to the animal or human an effective amount of a synthetic immunogen comprising: 
 (i) a promiscuous helper T-lymphocyte epitope selected from the group consisting of SEQ ID NO: 8 of measles virus protein F (MVP-F). SEQ ID NO: 2 of tetanus toxoid (TT), SEQ ID NO: 4 of tetanus toxoid (TT), and SEQ ID NO: 3 of malaria circynsoiriziute protein (M-CSP); fused through    (ii) a spacer peptide selected from the group consisting of Gly-Pro-Ser-Leu (SEQ ID NO: 5), Ser-Ser-Gly-Pro-Ser-Leu (SEQ ID NO: 6), and Ser-Ser-Gly-Pro-Ser-Leu-Lys-Leu (SEQ ID NO: 7) to    (iii) a GnRH immunomimic peptide comprising either the amino acid sequence of SEQ ID NO: 1, or amino acids 2-10 of SEQ ID NO: 1.    
     
     
         18 . The method according to  claim 17 , wherein the T-lymphocyte epitope is fused through the spacer peptide to the amino-terminus or the carboxy-terminus of the GnRH-immunomimic peptide.  
     
     
         19 . The method according to  claim 18 , wherein the synthetic immunogen further comprises a second GnRH immunomimic peptide comprising either the amino acid sequence of SEQ ID NO: 1, or amino acids 2-10 of SEQ ID NO: 1, and wherein the second GnRH immunomimic peptide is fused at its carboxy-terminus or its amino-terminus through a spacer peptide to the T-lymphocyte epitope.  
     
     
         20 . The method according to  claim 17 , wherein the T-lymphocyte epitope is fused through a spacer peptide to the amino-terminus of the GnRH-immunomimic peptide.  
     
     
         21 . The method according to  claim 17 , wherein the synthetic immunogen comprises a GnRH-immunomimic peptide having an acetylated amino-terminal glutamic acid or an amidated carboxy-terminal glycine.  
     
     
         22 . A method of inducing specific antibodies against GnRH in an animal comprising administering to the animal an effective amount of a synthetic immunogen comprising: a promiscuous helper T-lymphocyte epitope fined through a spacer peptide to a GnRH immunomimic peptide selected from the group consisting of the peptide defined by SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 11, SEQ ID NO: 12, SEQ ID NO: 13, SEQ ID NO: 14, SEQ ID NO; 15, SEQ ID NO: 16, SEQ ID NO: 17, SEQ ID NO: 18, SEQ ID NO: 19, and SEQ ID NO: 20.  
     
     
         23 . The method according to  claim 22 , wherein the synthetic immunogen is the peptide defined by SEQ ID NO: 10 or SEQ ID NO: 11.  
     
     
         24 . A method of inducing specific antibodies against GnRH in an animal comprising administering to the animal an effective amount of a combination of synthetic inmmunogens comprising at least two different synthetic immunogens selected from the group consisting of the peptides defined by SEQ ID NO: 9, SEQ ID NO: 10, SEQ ID NO: 11, SEQ ID NO: 12, SEQ ID NO: 13, SEQ ID NO: 14, SEQ ID NO: 15, SEQ ID NO: 16, SEQ ID NO: 17, SEQ ID NO: 18, SEQ ID NO: 19, and SEQ ID NO: 20.  
     
     
         25 . The method according to  claim 24 , wherein the combination of synthetic immunogen comprises: 
 (i) the synthetic immunogen defined by SEQ ID NO: 10; and    (ii) the synthetic immunogen defined by SEQ ID NO: 11.