Flow cytometric analysis of Epstein-Barr virus receptor among the different B-cell subpopulations using simultaneous two-color immunofluorescence

The distribution of Epstein-Barr virus receptor (EBVR) among the different B-cell subpopulations was analyzed by flow cytometry, using simultaneous two-color immunofluorescence of EBVR and cell-surface markers. The expression of EBVR was established by the binding of fluorescein isothiocyanate (FITC)-labeled EBV to the cells, while surface markers were stained by phycoerythrin (PE)-indirect immunofluorescence, using monoclonal antibodies. All cells of both the resting B-cell subpopulation defined by L30 and the B-cell subpopulations expressing surface IgM, IgD, IgA, and IgG were EBVR-positive. In contrast, EBVR was absent from about 10% cells of the activated B-cell subpopulation recognized by OKT9, as well as from about 10% cells of the highly differentiated B-cell subpopulation which reacted with OKT10. These results suggest that the expression of EBVR on the B-cell lineage varies with the maturation stage and with the state of activation. This postulation was further supported by analyses based on in vitro B-cell activation.