Regulation of Human B Cell Growth

The study of human B cell function involves examination of the events leading to maturation of B cells from B lineage lymphoid progenitor cells as well as the stages of activation, proliferation and differentiation which mature resting B lymphocytes must undergo to become immunoglobulin producing plasma cells [1–3]. In human B cell physiology (as opposed to murine B cell physiology) there appear to be molecules which act only at specific stages to induce either activation, proliferation or differentiation. However, as in murine B cell physiology, there are also molecules which can act at various stages. Antigen or anti-Ig will activate cells while B cell growth factors (BCGFs) [4–8] will induce their proliferation and B cell differentiation factors including interleukin-6 (IL-6) [9–11] will induce their differentiation. IL-2 in high concentrations can induce activation [12], proliferation, and differentiation [13] of human lymphocytes. In the next section, we will discuss some of our work examining the action of BCGFs in the regulation of normal human B cell proliferation.