Plasma B cells

Plasma B cells (or plasma cells) are the terminal, fully differentiated effector state of activated B lymphocytes. They are antibody factories, specializing in the massive secretion of antibodies of a single specificity. They possess extensive endoplasmic reticulum and a prominent Golgi apparatus to support high-rate protein synthesis. Most are short-lived, but some become long-lived plasma cells that reside in the bone marrow, providing sustained antibody levels.