Characterization of Two Murine Monoclonal Antibodies Reactive with Human B Cells

Abstract

Two monoclonal antibodies, HH1 and HH2, are described. Both reacted selectively with surface Ig (sIg)-positive human B cells. Both antibodies stained on average 7-8% of peripheral blood mononuclear cells. They have not been found to react with cells or cell lines of other hematopoietic cell lineages, except that HH2 was positive on a small percentage of cells of the erythroid cell line K562. The MW of the HH1 antigen was 95 kD [kilodalton], as established by Western blotting. Neither of these 2 antibodies reacted with Ig determinants, Fc receptors, complement receptors, or known class-I or class-II molecules. A combination of these antibodies was used in a direct panning technique for high-yield enrichment of normal B lymphocytes from peripheral blood. The enriched B cells could be further purified by lysis of T cells (final yield, on average 72 .+-. 8% of initial B cells) or by a second panning (yield, 35 .+-. 11%). The purified B cells contained < 1% contaminating T cells and < 0.5% monocytes and were used in an assay for B-cell-stimulating factor which they showed a normal and very reproducible proliferative response.