07/02/2024
Understanding immunity
If we see the immune system as a whole we see it better. The common view is that the immune system is our defence against infections. This is still the default explanation in medical textbooks and websites, and for most people preventing infection is an understandable priority. However a better way to understand and support immunity is to see it as something much wider than that.
The immune system is a vast array of interlinked mechanisms designed to distinguish substances that are normally found in the body from those that should not be there, and then to set these up for removal.
Why the need for this vigilance? The main focus of the immune system is on proteins and their larger fragments (peptides), as well as other complex molecules. These are known as antigens. However these are the same kind of compounds as the messengers and enablers within the body, the lines of communication between our cells, and the way they have of affecting each other. Our healthy functions would be impossible if internal communications were disrupted by agents that should not be there. So our bodies expend huge resources to keep the channels clear.
When we look at where disruptions to our internal communications can come then we can see that infections are only a minor source. There are two constant and major sources of antigens into the bloodstream and circulating fluids:
1. Our food. This is obviously made up of foreign materials, and we would suffer great harm for example if food was injected straight into our tissues. We rely on a healthy digestive system to make food safe. Our digestive juices not only sterilise our food and reduce infection from this source, but render large antigenic molecules into small safe building blocks (eg amino acids and simple sugars).
2. The internal contents of our own cells. Proteins inside a cell belong just there. Mostly they have no role in the body fluids and often become antigens if they get out. Cells die and are recycled constantly. This is normally done very rigorously so that internal contents are pre-digested before the cell membrane is breached, a process known as apoptosis. Illness or severe tissue damage can disrupt apoptosis and many forms of immune disease are autoimmunity to our own intracellular contents.
The main role of the immune system is to deliver preventive and eliminative measures against antigenic junk from any source. It also provides an intricate fallback to identify, isolate and flag anything that slips through into the body fluids, so that it can be disposed of.
Essentially therefore the immune system regulates our internal environment. It determines our health. It is also individual: my immune system is also as unique as my fingerprint – it has my name on it!
Note: this broader view of immunity is not new. One of the founding French immunologists Dr Pierre Grabar, wrote that the immune system is a complex ‘transport’ system designed to identify and carry antigens out of the body, particularly from the gut and after cell death.
However because of their complexity immune responses can go wrong. Many modern health conditions, especially if they are long term and severe, involve some degree of immune disruption, particularly autoimmunity, when our immune system targets our own tissues. We should understand the immune system as well as possible so as to develop herbal strategies that may help when it goes wrong.
