Health, disease and the development of medicines study guide

Monoclonal antibodies are highly specific antibodies that are produced from a single clone of B lymphocytes. The process of creating them involves a technique called hybridoma technology. Firstly, an animal is immunised with a specific antigen to stimulate its immune system to produce lymphocytes that make the desired antibody. These lymphocytes are then extracted, but they have a limited lifespan and do not divide indefinitely in culture. To overcome this limitation, they are fused with myeloma cells (a type of cancer cell) which are immortal and can divide indefinitely. The resulting hybrid cells, called hybridomas, possess both the antibody-producing capability of the lymphocyte and the rapid division characteristic of the myeloma cell. These hybridoma cells are then screened to identify and select those that produce the desired antibody. Once selected, these hybridoma cells are cultured to produce large quantities of identical monoclonal antibodies for various applications.

The specific immune system provides a targeted defence against disease. When the human body is exposed to a pathogen, it recognises foreign molecules called antigens on the pathogen's surface. These antigens trigger a specific immune response, leading to the production of antibodies by specialised white blood cells. Antibodies are proteins that specifically bind to and neutralise the invading pathogen. In addition to antibody production, exposure to antigens also stimulates the creation of memory lymphocytes (both B and T lymphocytes). These memory cells persist in the body for long periods, sometimes for life. If the same pathogen re-enters the body, these memory lymphocytes quickly recognise the antigen, initiating a much faster and stronger secondary immune response. This rapid and potent response effectively eliminates the pathogen before it can cause significant illness, providing long-term immunity.