In the specific immune response, effector cells are the cells that actually carry out the attack on the pathogen. In the humoral response the effector cells are plasma cells, and the effector stage is when they secrete large quantities of antibodies.Plasma cells are specialised for making and secreting protein. They have:
• a large amount of rough endoplasmic reticulum, where ribosomes synthesise the antibody polypeptides
• a large Golgi apparatus, which modifies the antibodies (adding carbohydrate to form glycoproteins) and packages them into vesicles
• many mitochondria to supply ATP for protein synthesis and secretion.Antibodies are released by exocytosis into the blood and lymph. A single plasma cell can secrete around 2000 antibody molecules per second, but plasma cells live for only a few days. All the antibodies from one clone of plasma cells are identical, with binding sites complementary to the antigen that triggered the response.The antibodies circulate in body fluids and bind to the antigen wherever it is found, forming antigen-antibody complexes. This labels pathogens for phagocytes, clumps them together and neutralises toxins (see the Antibodies lesson).
Worked example: a plasma cell secretes 2000 antibodies per second. In one hour it secretes 2000 × 3600 = 7 200 000 (7.2 × 106) antibodies.In a first infection, antibody concentration in the blood peaks after roughly 10 to 14 days. Once the antigen is removed, the plasma cells die and antibody levels fall, but memory cells remain.
• a large amount of rough endoplasmic reticulum, where ribosomes synthesise the antibody polypeptides
• a large Golgi apparatus, which modifies the antibodies (adding carbohydrate to form glycoproteins) and packages them into vesicles
• many mitochondria to supply ATP for protein synthesis and secretion.Antibodies are released by exocytosis into the blood and lymph. A single plasma cell can secrete around 2000 antibody molecules per second, but plasma cells live for only a few days. All the antibodies from one clone of plasma cells are identical, with binding sites complementary to the antigen that triggered the response.The antibodies circulate in body fluids and bind to the antigen wherever it is found, forming antigen-antibody complexes. This labels pathogens for phagocytes, clumps them together and neutralises toxins (see the Antibodies lesson).
Worked example: a plasma cell secretes 2000 antibodies per second. In one hour it secretes 2000 × 3600 = 7 200 000 (7.2 × 106) antibodies.In a first infection, antibody concentration in the blood peaks after roughly 10 to 14 days. Once the antigen is removed, the plasma cells die and antibody levels fall, but memory cells remain.