The Human B Cell Lineage Studied with Monoclonal Antibodies

B lymphocytes derive from bone marrow pluripotent stem cells and mature through a number of discernible stages. Antigen stimulates B cells to differentiate either into memory cells or into antibody-producing plasma cells. Distinct stages of B cell maturation can be recognised by the expression of immunoglobulin (Ig), which is the characteristic functional product of B lymphocytes. However, studies of B cell maturation and differentiation based solely on Ig expression lack detail, and additional markers are needed to allow a clearer understanding of the entire B cell lineage.