The immune system
The immune system is essential to keeping healthy and being able to make the changes needed for a new life. It protects the body from invaders or rogue cells that can do harm, and if it’s a bit “lazy” unwanted cells can avoid detection. However, if it’s too aggressive then healthy tissue can be removed, so both imbalances can reduce health and encourage disease.
The immune system works constantly and in the average adult between 50 to 70 billion old or damaged cells are removed and recycled a day in a process called “apoptosis”. This is essential for us to stay healthy, and it also means the body can quickly make repairs and change structures when it needs to. This is particularly important in puberty, and changes to the womb and its blood supply are essential for a pregnancy to progress.
There are two parts to the immune system:
(1) The innate immune system
This is the body’s first, non-specific line of defence. At its most simple this includes the protection our skin gives us, as well as tears, saliva and the mucus lining the digestive tract and lungs which trap possible threats to the body.
If a bacteria or virus enters the body white blood cells called “leukocytes”, “macrophages” and “neutrophils” can literally “eat” or destroy them with toxic chemicals. These white blood cells aren’t specific to any diseases but simply recognise ‘self’ or ‘non-self’ markers on the cell walls and act on that basis.
(2) The acquired immune system
This is the body’s second line of defence. It’s a specialised “learnt” response where certain white blood cells bind to pathogens (infectious agents). They recognise them because the person’s either been exposed to (or been immunised against) the illness before. There are exceptions to this general rule, as it’s possible for this type of response to be passed to babies from their mothers. There are two specialist cell types:
- B cells which develop in the bone marrow
- T cells which originate in the thymus gland that’s next to the heart
The acquired immune system response is able to produce a rapid and specific response to a recognised threat, which is a step up from a general innate response. It needs to be able to recognise the intruder to do this…. which is where antibodies and antigens come in.
Antibodies and Antigens
- ‘Antibodies’ are types of proteins (they’re also known as ‘immunoglobins’ (Ig) produced by the B cells and their function is to identify antigens.
- ‘Antigens’ are other specific proteins, usually found on foreign objects like bacteria and viruses (but can also be hormones made by the body) and the term ‘antigen’ comes from the understanding that they stimulate antibody generation.
- Neither antibodies nor antigens are “alive” as such, but they’re specific types of proteins, with an exact match between the structure of an antibody and its antigen which allows them to physically bind together with precision; like a lock and key.
- Once the antibody attaches to its antigen, the antigen’s been “tagged”, and other players in the body can now recognise and respond to the antigen. In terms of immunity, this often means attacking and destroying the tagged object.
- The specialist antibodies are coded according to their antigen receptors (called “clusters of differentiation” “CD”). There are now hundreds of known CDs, and a single antibody can have a number of CDs.
When the body’s first exposed to an infectious foreign substance (which will have antigens on it) it produces B cells ‘primed’ to make antibodies to tag it. The antibody that’s the perfect match is then produced in large numbers and a successful antibody to a virus or bacteria can remain in the body a long time. The advantage of an “acquired immunity” is that when a person’s exposed to an illness again it can rapidly produce large numbers of antibodies that stop this particular infection before it can damage the body too much.
The body produces different classes of antibodies to the same antigen, which relate to different ‘layers’ of the immune system:
- IgM is antibodies in the blood.
- IgG is antibodies in the lymphatic system and lymph nodes.
- IgA is antibodies in the mucous membranes.
The immune system in balance
The immune system has two sides to it:
- The aggressive autoimmune response (also called the Th1 response).
- The restraining suppressive response (also called the Th2 response).
A relative balance between the Th1 and Th2 immune responses is needed to maintain good health, and this is especially true in pregnancy:
- An immune system that’s too aggressive (Th1 excess, or Th2 deficient) can lead to immune cells attacking healthy cells.
- An immune system that’s too suppressive (Th2 excess, or Th1 deficient) can result in the immune system failing to protect the body against foreign illnesses, or not recognising and removing dysfunctional cells, such as cancers.
Many factors contribute to the health and balance of the immune system, including genetics, diet, lifestyle, the environment and stress. morefertile® promotes natural ways to raise health and fertility, which includes explaining science.
