Epitope design for the induction of antibodies which recognize a family of molecules: example of monoclonal antibodies to 2'-5' oligoadenylates.
Monoclonal antibodies directed against 2'-5' oligoadenylates (pxA(2'pA)n 0 less than or equal to x less than or equal to 3, n greater than or equal to 1) have been obtained with A2'pA-succinyl albumin as immunogen. A competition assay using 125I iodo succinyl A2'pA tyrosine methyl ester as a tracer and thirty chemically related analogs was used to investigate the molecular basis governing their reactivity. We show that the use of a hapten as small as A2'pA elicits antibodies of high affinity for this dinucleotide (Kd = 2 x 10(-11) M). The overall immunoreactivity is essentially shared between the first moiety (5'OH A2'p) and the 2'-5' phosphodiester bond; however, the second moiety is an integral part of the epitope which extends up to the spacer. Therefore, any modification at the 5'OH end or of the 2'-5' structure dramatically decreases the binding. Modifications at the 2' and/or 3' ends are favourable if they mimic the immunogen. Modifications of the ribose backbone reveal the part of antigenicity due to the different 3'OH groups. Substitution of the bases show that the second adenine is implicated in the antigenicity. We demonstrate how, with such requirements, these antibodies recognize A2'pA alone or at the 5' end of or else included in longer oligonucleotides.
D000227:Adenine Nucleotides / Q000276:immunology*; D000249:Adenosine Monophosphate / Q000031:analogs & derivatives / Q000276:immunology; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000917:Antibody Formation; D003429:Cross Reactions; D015226:Dinucleoside Phosphates; D000939:Epitopes / Q000276:immunology*; D008297:Male; D008958:Models, Molecular; D009843:Oligoribonucleotides / Q000276:immunology*; D051381:Rats; D011919:Rats, Inbred Strains; D013329:Structure-Activity Relationship
D000227:Adenine Nucleotides; D000911:Antibodies, Monoclonal; D015226:Dinucleoside Phosphates; D000939:Epitopes; D009843:Oligoribonucleotides; C031130:adenylyl-(2'-5')-adenosine; D000249:Adenosine Monophosphate; C023505:2',5'-oligoadenylate