CHARACTERIZATION OF A MONOCLONAL ANTI-BETA-2-MICROGLOBULIN ANTIBODY AND ITS USE IN THE GENETIC AND BIOCHEMICAL-ANALYSIS OF MAJOR HISTOCOMPATIBILITY ANTIGENS

A monoclonal anti‐β2‐microglobulin (BBM.1 antibody) was produced by cell fusion between the mouse myeloma, P3‐X 63‐Ag8, and spleen cells from a BALB/c mouse immunized with Molt 4, a human T cell line. BBM.1 antibody was fully inhibited by soluble β‐microglobulin and purified HLA‐A, B antigens and reacted with humanmouse somatic cell hybrids only if they had chromosome 15 and expressed human β‐microglobulin. It was cytotoxic in complement‐dependent lysis and of the IgG class. BBM.1 and a monoclonal anti‐HLA‐A, B, C glycoprotein antibody, W6/32 (Barnstable, C. J. et al., Cell 1978. 14: 9.), were used to quantitate relative amounts of β2 ‐microglobulin and HLA‐A, B, C glycoproteins on different human cell types. Thymocytes and the Molt 4 cell line showed a considerable excess of β2‐microglobulin over HLA‐A, B, C glycoproteins, as measured by W6/32 reactivity. B cell lines, peripheral blood lymphocytes, fibroblasts, a HeLa cell derivative, and HSB 2, another T cell line, had equal amounts. Immunological cross‐reactions between HLA‐A, B, C antigens and β‐microgloglobulin and their homologues in other species were detected with the BBM.1 and W6/32 antibodies. The W6/32 antigenic determinant appears to be more highly conserved than that recognized by the BBM.1 antibody. Copyright © 1979 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim