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.
Cytokines are substances produced by some immune system cells to communicate with other cells.
Types of cytokines include lymphokines, interferons , interleukins , and colony-stimulating factors . These cytokines attack cancer cells directly. Nonspecific Immunomodulating Agents Nonspecific immunomodulating agents are substances that stimulate or indirectly augment the immune system. Often, these agents target key immune system cells and cause secondary responses such as increased production of cytokines and immunoglobulins. BCG, which has been widely used as a tuberculosis vaccine , is used in the treatment of superficial bladder cancer following surgery.