Characterization of BLR1⁻ B cells. PBL were incubated with CD19-PE, BLR1-biotin/strepavidin-cychrome, and FITC-conjugated CD38 MoAb. CD19⁺ cells were gated and analyzed. If not indicated otherwise, the horizontal and vertical scales are log 10 antibody fluorescence intensities. Lymphocyte forward scatter intensity (FSC) reflects cell size. Representative experiments from an HIV⁺ (WR5) and an HIV⁻ individual are shown.