Production of Subtype-Specific Antipeptide Antibodies to Human Interferon-α1 and -α4

Antibodies that are specific to the human interferon (IFN)-α1 and -α4 subtypes have been produced by immunizing rabbits with two short synthetic peptides, corresponding to residues 99-111 of IFN-α, and residues 37-50 of IFN-α4, respectively. The IFN-α, peptide has at least three closely clustered residues that are different from those in the other IFN-α subtypes, while the IFN-α4 peptide has only two unique amino acid residues, separated by five common residues. The antibodies raised against the IFN-α1 peptide react with recombinant human IFN-α1 but do not cross-react with recombinant human IFN-α4 or IFN-α2. The antibodies raised against the IFN-α4 peptide react with IFN-α4, crossreact with IFN-α1 but not with IFN-α2; the affinity of the antibodies to IFN-α1, however, is at least 10 times lower than their affinity to IFN-α4.