Lymphocytes

The specific immune response depends on B and T lymphocytes.The main types of T lymphocytes are T helper cells, T killer cells, T memory cells and T regulator cells.B cells are B plasma cells, B effector cells and B memory cells.1. T helper cells T helper cells bind to antigens on APCs and then produce interleukins to stimulate B cells to produce more antibodies, attract macrophages and stimulate phagocytosis and stimulate the production of T cells.2. T killer cells produce a chemical called perforin that kills bacteria by making holes in the cell membrane.3 . T regulator cells suppress the immune system so the immune response is stopped once a pathogen has been eliminated.4. T memory cells live for a long while after the primary immune response. If they encounter the antigen a second time they divide rapidly to form a huge number of clones of T killer cells to destroy the pathogen.5. B plasma cells produce antibodies and secrete them into the blood plasma
B effector cells divide to form B plasma cell clones
B memory cells provide the immunological memory and enable a rapid response when the antigen is encountered a second time.