Identification, production, and characterization of murine monoclonal antibody (LO-22) recognizing 12 native species of human alpha interferon.

The present study describes the development of a murine monoclonal antibody (LO-22) directed against 12 native species of HuIFN-alpha. Mice were immunized with purified HuIFN-alpha preparations containing all native species of HuIFN-alpha and spleen cells from immunized mice were fused with P3X63MS1 mouse myeloma cells. Positive hybridoma clones secreting antibodies to HuIFN-alpha were identified by means of a new, extremely sensitive biological semisolid binding assay which was able to disclose positive hybridoma clones consisting of less than 30 hybridoma cells. Antibody affinity columns, made by the LO-22 IgG and monospecific, but polyclonal rabbit IgG, showed identical binding abilities as demonstrated by comparative affinity chromatographies in that the same number of IFN species (12 in total) were found in eluates from parallel experiments. Since LO-22 IgG also recognizes porcine leucocyte interferon, it is suggested that the LO-22 is directed against a common epitope which has been very well conserved in the HuIFN-alpha system, per se. It is suggested that the LO-22 IgG can be used for purification of all HuIFN-alpha proteins--be they recombinantly derived or native--but exerting the common determinant. Preliminary experiments have shown that the LO-22 IgG is highly suitable for ELISA tests.