- Plasma Cells are effector B-cells which are actively synthesizing and secreting large amounts of Antibody. Consequently, these leukocytes represent the final end-point of B-cell differentiation and are the main effectors of Humoral Immunity.
- Plasma Cells are specialized for synthesis and excretion of large amounts of antigen-specific antibody which targets microbes for destruction by other immune cells. Indeed, Plasma Cells are the primary source of circulating antibodies within the plasma and extracellular fluid.
- Like all lymphocytes plasma cells possess a large unlobulated nucleus, justifying their classification as Mononuclear Cells. To maintain their enormous synthetic and secretory activity, Plasma Cells possess an expanded Endoplasmic Reticulum. To accommodate this expanded organelle, Plasma Cells possess a more prominent cytosol than do most lymphocytes.
- Plasma Cells develop from naive, mature B-cells following the processes described in Humoral Immunity. Briefly, differentiation to a Plasma Cell requires a naive, mature B-cell to encounter its specific antigen and be stimulated with cytokines from Th2 Cells.