Cancer may develop when the immune system breaks down or is not functioning adequately. Biological therapies are designed to repair, stimulate, or enhance the immune system s responses. Types of lymphocytes include B cells , T cells , and Natural Killer cells . Each type of B cell makes one specific antibody , which recognizes one specific antigen. T cells also regulate the immune response by signaling other immune system defenders.
T cells work primarily by producing proteins called lymphokines.
They attack without first having to recognize a specific antigen. Monocytes are white blood cells that can swallow and digest microscopic organisms and particles in a process known as phagocytosis. Monocytes can also travel into tissue and become macrophages , or big eaters. Antibodies respond to antigens by latching on to, or binding with, the antigens. Specific antibodies match specific antigens, fitting together much the way a key fits a lock.