Subtype-specificity of antipeptide antibodies raised against unique sequences of human interferons-α

Abstract A strategy for the production of human interferon-α (IFN-α) subtype-specific antibodies, based on immunizing rabbits with short unique synthetic peptides coupled to protein carriers, has been validated. These peptides correspond to amino acid residues 99–111 of IFN-α 1, 50–57 and 103–116 of IFN-α2, and 37–50 of IFN-α4. The antipeptide antibodies anti-IFN α 1( 99−111 ), anti-IFN α 2( 50−57 C ), anti-IFN α 2( 103−116 and anti-IFN α 4( C 37–50 ) were tested by ELISA and Western blotting for their reactivity with immunoaffinitypurified recombinant human IFN-α 1, -α2b and -α4a. The anti-IFN α 1 (99−111) and anti-IFN α 2 (50–57 C ) reacted with their corresponding IFN-α and did not crossreact with the other IFN subtypes. The anti-IFNα 2( 103–116 ) reacted with IFN-α 2b and also crossreacted slightly with the other subtypes. The anti-IFNα 4( C37–50 ) reacted well with IFN-α 4a, crossreacted with significantly lower affinity with IFN-α 1 and did not bind IFN-α2b. Residues 104–107 and 108–111 are the major components of the epitopes recognized by anti-IFN α 1 (99–111) and anti-IFN α 2 (103–116) , respectively, as determined by ELISA against overlapping octapeptides.