The many faces of B Cells: From generation of antibodies to immune regulation

B lineage lymphocytes (B cells) produce exquisitely specific and long-lasting antibodies that recognize a broad and ever-changing array of foreign antigens and microbial pathogens. Perturbations in B-cell development maturation lead to specific immune disturbances. Certain features intrinsic to fetal and neonatal B cells contribute to what has been called the relative immunodeficiency of infancy. Although the primary function of B lineage cells is to produce antibodies for host defense, emerging data show that B cells are key activators and regulators of the immune response.