Monoclonal antibodies

• What are monoclonal antibodies?

  proteins that are produced to target particular cells/ chemicals in the body
• Lymphocytes - make antibodies but can't divide

  Tumour cells - don;t make antibodies but do divide
• Production of monoclonal antibodies:

  1. All mammals produce lymphocytes - scientists combine mice lymphocytes (have been stimulated to make a particular antibody) with a tumour cell to make a hybridoma
  2. Single hybridoma cells divide to make a large number of identical cells that all produce the same antibodies.
  3. These antibodies are collected and purified = monoclonal antibodies - antibodies produced from a single clone of cells.

  
• Monoclonal antibodies bind to one specific antigen, making them useful in many ways, including pregnancy tests, disease diagnosis, measuring and monitoring, and research.
• Monoclonal antibodies are used in pregnancy tests to bind to the hormone 'human chorionic gonadotrophin', which is made in the early stages of pregnancy.
• Tiny amounts of hormone are passed out of the body in the urine.
• Monoclonal antibodies in the pregnancy test bind to the hormone if it is present, producing the colour change.
• Monoclonal antibodies are used in disease diagnosis to bind to specific antigens found on pathogens, blood clots, and cancer cells.
• Monoclonal antibodies may carry markers that make it easy for the doctor to detect before they are affecting a person's health, for example, the blood test for prostate cancer uses monoclonal antibodies to bind to prostate specific antigens.
• Monoclonal antibodies are used in measuring and monitoring in hospitals and labs to measure or monitor the levels of hormones and other chemicals in the blood, for example, screening donated blood for an HIV infection.
• Mabs treating cancer:

  1. To block receptors on the surface of cancer cells + stop the cells growing + dividing
  2. Used to carry toxic drugs / radioactive substances for radiation therapy / chemicals that stop cells growing + dividing to attack the cancer cells directly without harming other cells in the body.
  3. To trigger the immune system to recognise, attack + destroy cancer cells
• When monoclonal antibodies bind to the desired molecules, scientists can see what has happened by observing the build up of fluorescence.
• Monoclonal antibodies are used in research to locate or identify specific molecules in a cell or tissue.
• Scientists produce monoclonal antibodies linked to a molecule of fluorescent dye.
• Advantages of monoclonal antibodies:

  • only bind to the specific diseased / damaged cells that need treatment. Healthy cells aren't affected at all. In contrast, conventional drug treatment is carried all around the body in the blood + can have a devastating effect on healthy cells as well as e.g. Cancer cells.
  • The specificity of MAbs means that they can be used to treat a wide range of conditions.
  • Currently they are expensive but they could become cheaper to develop than conventional drugs because the treatemtns would be based on a tested technology
• MAbs are currently expensive.
• MAbs were not widely used due to the creation of more side effects than expected due to the use of mouse cells in the formation of hybridoma cells.
• The production of mouse-human hybrid cells and the use of fraction of antibodies to carry drugs to target cells are reducing side effects.
• Producing the right monoclonal antibodies and attaching them to drugs and other compounds is more difficult than expected.
• MAbs are now being used in different ways due to the development of more skills and technology.