Establishment of monoclonal antibody NI-58 which inhibits homotypic cell adhesion of LPS-stimulated U937 cells

A mouse monoclonal IgG1 antibody, referred to as NI-58, has been produced. In immunofluorescence assay, this antibody reacted with myelomonocytes, EBV-B cells, Burkitt's lymphoma cells, T cell leukemia cells and peripheral blood mononuclear cells, but not with erythroid cells. The surface antigen on U937 cells recognized by NI-58 had a molecular size of 65kDa as determined by immunoblotting analysis. As a biological function, NI-58 strongly inhibited the homotypic cell adhesion of LPS-stimulated U937 cells. It was found that the antigen defined by NI-58 was distinct from CD54 (intercellular adhesion molecule-1) in it's pattern of cellular expression and molecular weight, suggesting that NI-58 recognizes a new adhesion molecule and inhibits the homotypic cell adhesion of LPS-stimulated U937 cells.