Immunology is the study of the system that protects our body from infections. Problems with the immune system are linked to many serious health conditions. Our immunology researchers are discovering how the immune system functions in health and disease.
One-third of our research effort is devoted to immunology. Our researchers are:
Immunology is the study of the immune system, which is comprised of specialised cells and molecules. These work together to protect our body from infection by bacteria, viruses, parasites and fungi. The immune system can also prevent the formation of some cancers.
Our immune system can stop most microbes from entering the body, and can stifle their growth and spread. Sometimes, the immune system cannot prevent an infection. Some microbes have developed sophisticated strategies to evade the immune system, allowing them to survive and reproduce within the body.
Our immune system has diverse strategies to prevent infection. The functions of the immune system can be broadly divided into:
Innate immune system: responds rapidly to microbes, but does not alter significantly on repeat exposure. Important aspects of this are:
Adaptive immune system: develops ‘memory’ to microbes, allowing subsequent immune responses to the same microbe to be faster and larger. This immunological memory can last a lifetime.
Important aspects of adaptive immunity are:
Innate immune responses typically occur more rapidly than adaptive responses. The innate and adaptive immune systems have many interactions, and can involve some of the same cells and molecules.
The immune system involves many different types of cells working together. Many of these are ‘white blood cells’ that develop from blood stem cells in the bone marrow.
Our researchers are contributing to the understanding of how immune cells develop and function. In doing this, they have revealed many sub-types of these cells.
Important immune cells include:
These are innate immune cells that can engulf (phagocytose) microbes or other particles. They are important in triggering inflammation, and some can alert adaptive immune cells to an infection. Important phagocytes include:
These cells include adaptive and innate immune components, with many functions in controlling, stimulating and executing immune responses. Long-lived memory lymphocytes are the source of lifelong immunity to certain infections.
The broad types of lymphocytes are:
There are many factors released by immune cells that are important for immune reactions. These include:
For good health, both innate and adaptive immune responses need to:
The immune system contains many safeguards that regulate its functions. Many strategies are used to prevent harmful immune responses. This includes systems for destroying or silencing potentially harmful cells that could attack the body’s own tissues.
Usually the immune system can distinguish our own tissues from invading microbes, and respond appropriately, killing the microbes or infected cells but not harming uninfected or otherwise healthy cells. Defective control of the immune response, leading to misdirected, excessive or inadequate immune responses, underly many immune disorders.
Inflammatory disorders occur when the immune system causes excessive inflammation that damages the body. This may be triggered by an infection, such as in rheumatic fever or occur for no known reason, such as in inflammatory bowel disease.
Autoimmunity is a type of inflammatory disorder that occurs when the immune system mistakenly attacks the body’s own tissues. These disorders are caused by lymphocytes or antibodies reacting to the body’s own tissues.
Significant autoimmune diseases include:
Allergy occurs when the immune system over-reacts to harmless factors in our diet or environment.
Immunodeficiency is a weakened immune system. This causes a person to be infected by microbes more easily than a healthy person.
The normal functioning of our immune system is vital to our health. Immune cells can also be harnessed to treat disease, a field called immunotherapy. Examples of immunotherapy include: