Antibodies to Surface IgM Can Accelerate Apoptosis of Mature B-Lymphocytes at Sub - Stimulatory Concentrations

Antibody to B-cell surface immunoglobulin D (IgD) or surface IgM results in crosslinking of Ig molecules and signal transduction. The function of these surface immunoglobulins has traditionally been investigated by extensive crosslinking experiments and interest has been focused on activation assays. We investigated the effects on apoptosis of culture with anti-(mathematical symbol) antibody (anti-(mathematical symbol)) concentrations ranging from 0.001 (mathematical symbol) mL-1 to 50 (mathematical symbol)g mL-1. Previous experiments have shown that weak dose anti-(mathematical symbol) antibody (anti-(mathematical symbol)) increases mature B-cell apoptosis at both 16- and 64-hour time points, while greater dose anti-(mathematical symbol) results in cell cycle entry at 64 hours. The question addressed is whether anti-(mathematical symbol) induces the same biphasic response. After 16 hours of culture, both a monoclonal and a polyclonal anti-(mathematical symbol). at weak concentrations caused much less of an increase in apoptosis than anti-(mathematical symbol), although cell cycle entry at 64 hours was similar. Together, these results suggest a mechanism for low-zone B-cell tolerance induction, a process that was previously thought only to occur in T-cells