MONOCLONAL-ANTIBODIES TO HUMAN INTERFERON-GAMMA .2. ANTIBODIES WITH NEUTRALIZING ACTIVITY

Two types of hybridomas secreting monoclonal antibodies (MAB) with neutralizing activity against human interferon-γ (HuIFN-γ) were obtained by somatic cell hybridization between mouse myeloma P3UI cells and spleen cells from BALB/c mice immunized with purified recombinant HuIFN-γ and a conjugate of a synthetic amino-terminal peptide (residues 4-21) of HuIFN-γ and bovine thyroglobulin. One of these MAB recognized the amino-terminal region (residues 4-21) of HuIFN-γ, and the other recognized some region in the internal part (residues 22-130) of the molecule. These results suggest that another region, in addition to the amino-terminal region, contributed to the biological activity of rHuIFN-γ. A combination of one of these MAB and a previously described MAB directed to the carboxyl-terminal region (residues 131-146) of HuIFN-γ enables a quantitative and sensitive assay method of biologically active rHuIFN-γ.