A human monoclonal antibody that detects HLA‐A1, A23 and A24 antigens

Abstract

We report the production and characterization of a human monoclonal IgM (μ, μ) antibody recognizing the HLA A1, A23 and A24 antigens. B lymphocytes obtained from a multiparous Japanese woman were transformed in vitro by Epstein‐Barr virus, screened with an immune adherence assay, and fused with a murine myeloma cell line, P3‐X63‐Ag8.653. After subcloning by limiting dilution three times, a stable antibody‐secreting hybridoma cell line, 4‐35‐7, was identified. The culture supernant had a titer of 1:32‐64 against each of A1‐, A23‐ and A24‐positive lymphocyte panels, and showed complete correlation (r=1.00) with the A1, A23 and A24 antigens on a lymphocyte panel of 287 unrelated, class I HLA‐typed donors by the NIH cytotoxicity assay. Monoclonality of the antibody was ensured by Southern blot analysis of the human immunoglobulin heavy chain gene of 4–35–7. In view of the published data on HLA class I nucleotide sequences, the antibody may recognize an antigeneic determinant including two amino acid residues, Asp‐166 and Gly‐167, in the α2 helix of the class I molecule that are specific for A1, A23 and A24 so far analyzed.