Infectious diseases - immunity

Vaccines are not the only form of medical treatment which relies on the immune systemimmune system
The body's natural defence mechanism against infectious diseases. .

Monoclonal antibodiesmonoclonal antibodies
Antibodies all made from a single clone of specialist cells used in both medical diagnostics and treatments.  are antibodies which are made to target particular cells or chemicals in the body. Some lymphocytes (called B lymphocytesB lymphocytes
Lymphocytes made in the bone marrow that are found both in the lymph glands of the body and free in the blood once they mature. ) make antibodies but cannot divide. Scientists combine mouse B lymphocytes which have been stimulated to make a particular antibodyantibody
A protein in the blood which is produced in response to a specific antigen. Antibodies attach to antigens to remove them from the body. with a type of tumour cell to make a cell called a hybridomahybridoma
Hybridoma cells are formed by fusing a specific antibody-producing cell with a type of cancer cell that grows well in tissue culture. They produce monoclonal antibodies. .

Hybridoma cells can both make a specific antibody and divide. The hybridoma cells are clonedcloned
To propagate (an organism or cell) as a clone to make a large number of identical cells which all make the same antibodies. The antibodies are collected and purified. These are monoclonal antibodies - antibodies from a single clone of cells

• Pregnancy tests rely on monoclonal antibodies which bind to a hormone (HCG) which is made in the early stages of pregnancy. Tiny amounts of the hormone are passed out of the body in the urine. This is what is picked up by the monoclonal antibodies in the pregnancy test.

• Diagnosis of disease - monoclonal antibodies can be made which bind to specific antigenantigen
  A protein, nucleic acid, or other molecule, which can stimulate a response from the immune system. s on blood clotblood clot
  A mass of fibrin, platelets and red blood cells which form a solid mass and stop blood loss at a wound. s or on cancer cells. The monoclonal antibodies can also carry markers which make it easy for doctors to see where they have built up. This allows doctors to detect problems before they seriously affect a person's health. For example, the blood test for prostate cancer uses monoclonal antibodies to bind to prostrate-specific antigens.

• Treatment of disease - monoclonal antibodies can be used to carry drugs to specific tissues. Because they bind to the antigens in a tumour, for example, they can be used to take drugs or radioactive substances directly to the cancer cells.