Quantitation of β2-Microglobulin and HLA on the Surface of Human Cells

Relative amounts of beta2-microglobulin (beta2m) and of HLA specificities were analysed on the surface of resting unfractionated peripheral human lymphocytes, enriched B and T cells, and on in-vivo- and in-vitro-stimulated lymphoblasts. Single-cell cytofluorometry and a very sensitive radioimmunoassay were used to determine as closely as possible the absolute amounts of membrane-bound beta2m/HLA antigens. B and T "resting" and "stimulated" lymphoid cells express very similar numbers of beta2m and HLA antigenic determinants, respectively, per unit of surface area when compared with each group, although beta2m was found to exist in two- to three-fold excess of HLA.