B cells activated via CD40 and IL-4 undergo a division burst but require continued stimulation to maintain division, survival and differentiation.

Abstract

T cell stimulation of B cell proliferation during T-B collaboration requires membrane-bound stimulatory ligands, such as CD40 ligand and the secretion of soluble cytokines, such as IL-4. Nevertheless, it remains unclear whether T cell contact is required to provoke each consecutive B cell division, or whether B cells divide in a T cell-free burst following the initial stimulation. To test this, naive B cells were cultured with anti-CD40 monoclonal antibody (mAb) and IL-4 and, after various times, these stimuli were removed and the cells re-cultured with or without further stimulation. Following stimulus removal, B cells were able to continue proliferating, with the size of the B cell burst d..