Question
What are the major constituents of the human immune response?
Answer
The immune response is the way in which the body is able to defend itself from foreign pathogens or harmful substances. The immune response is a multi-tiered system which utilises a range of biological processes to protect against disease in a layered fashion of increasing specificity. The ‘innate’ immune system is the bodies first line of defence against invading pathogens, and is composed of a range of non-specific defences such as surface barriers; the skin, or natural killer cells, which are a component of the immune system that target and destroy compromised host cells such as tumours or those infected with a virus. The ‘adaptive’ immune system is the second line of defence which allows for a stronger more specific immune response through adaptability (as the name suggests) and immunological memory. The adaptive immune system is ‘antigen’ (a molecule which resides on the invading cell which triggers an immune response) specific, and upon detection of a foreign antigen, the body produces a range of cells to specifically target the invading pathogen, which after a short delay phase provides long term immunity to the specific pathogen through a process called immunological memory. Adaptation of pathogens through mutation can however, prevent the success of immunological memory, as the surface antigens they present may be altered triggering a new response from the adaptive immune system.
