Identification of Two Populations of Immunoglobulin-Bearing Lymphocytes in Man

Human peripheral blood lymphocytes bearing easily detectable surface immunoglobulin were quantitated with routine immunofluorescence procedures. The mean value in 17 healthy adults were 18% (range 9 to 30%). When the cells were preincubated at 37 degrees C and washed at the same temperature before staining, the mean value decreased to 9% (range 4.5 to 18%) (p less than 0.001). The mean value increased to 32% (range 15 to 49%) when the cells were prepared and washed at 4 degrees C, and this value was also significantly different from values at room temperature (p less than 0.01). These temperature-related effects were explained by IgG that remained bound to the cell membrane at 4 degrees C, but eluted at 37 degrees C in serum-free medium. The total number of Ig-bearing lymphocytes and T lymphocytes determined by rosette formation with sheep erythrocytes approached 100%. These studies indicate two populations of Ig-bearing lymphocytes in healthy subjects: one with surface-stable Ig determinants, and another that lacks these markers, but has receptors capable of binding IgG.