The negative surface charge density is a maturation marker of human B lymphocytes

Small resting B lymphocytes were highly enriched and completely depleted of all preactivated large B lymphocytes using countercurrent centrifugal elutriation and free flow electrophoresis. They required T lymphocytes, monocytes, and a mitogen to produce antibodies after 5 days of preincubation. Large activated B lymphocytes were obtained in cell fractions which were free of resting ones. They produced antibodies even in the absence of a mitogen. Two groups were distinguished, differing in their stage of differentiation and their negative surface charge density. The cells of one group had an electrophoretic mobility (EM) like resting B lymphocytes ranging from 0.85 to 0.99 X 10(-4) (cm2 V-1 s-1). They took 2 to 3 days of preincubation before they started to secrete antibodies. Interleukin 2 and pokeweed mitogen enhanced their antibody production capability. The cells of the other group had an EM between 0.99 and 1.13 X 10(-4) (cm2 V-1 s-1). They secreted antibodies even during the first day of incubation. The quantity of the antibodies which they produced depended only on the blood donor. It could not be influenced by a mitogen or by interleukin 2. The study shows that large B lymphocytes with high negative surface charge density are in a later maturation stage than those with lower negative surface charge density.